RFC 5519
Multicast Group Membership Discovery MIB
RFC 5519: Multicast Group Membership Discovery MIB 🦋
okay bestie, let's get into RFC 5519 💖 (part 1 of 6)
the title block tea ☕ This one is a Standards Track doc from April 2009. J. Chesterfield from the University of Cambridge and B. Haberman, Ed. from JHU/APL wrote it. It obsoletes RFC 2933 and RFC 3019, so those two are officially retired 💀. The title block doesn't list anything it updates.
Status of This Memo
So this section is basically the disclaimer part 🙈. The doc is an Internet standards track protocol for the Internet community, and it's asking people to chime in with discussion and suggestions for improvements. For the current standardization state and status, you check the latest "Internet Official Protocol Standards" (STD 1). And distribution of the memo is unlimited, so share away 🌸.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. ✨
This doc is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents, as they were on the publication date. The legal stuff lives at http://trustee.ietf.org/license-info. Read it carefully, because it explains your rights and restrictions for this doc 📜.
Abstract
The abstract is the quick pitch 💅. This memo defines a portion of the Management Information Base (MIB) for network management protocols in the Internet community. Specifically, it covers objects for managing the Internet Group Management Protocol (IGMP) and the Multicast Listener Discovery (MLD) protocol 🌈.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. The Internet-Standard Management Framework . . . . . . . . . . 2
3. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 38
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 39
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 39
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 40
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10.1. Normative References . . . . . . . . . . . . . . . . . . 40
10.2. Informative References . . . . . . . . . . . . . . . . . 411. Introduction ✨
okay so this memo is the MIB chunk for network management protocols across the Internet community 🧚. It covers the objects used to manage IGMP version 1 [RFC1112], version 2 [RFC2236], or version 3 [RFC3376], plus the Multicast Listener Discovery (MLD) protocol version 1 [RFC2710] or version 2 [RFC3810]. Both protocols give you multicast membership discovery. IGMP is for IP version 4 clients, and MLD is for IP version 6 clients 💖.
This version of the MIB obsoletes both RFC 2933 [RFC2933] and RFC 3019 [RFC3019]. It's giving one unified interface for both IGMP and MLD implementations, and it adds changes that enable "source filtering" in multicast clients 🔥. The MIB covers both router and host nodes, with management objects defined for each one.
2. The Internet-Standard Management Framework
If you want the full tour of the current Internet-Standard Management Framework docs, check section 7 of RFC 3410 [RFC3410] 🎀.
Managed objects are accessed through a virtual information store called the Management Information Base, or MIB. Usually you reach MIB objects through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant with SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580] 📚.
3. Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119] 🫶.
4. Overview
the MGMD (Multicast Group Membership Discovery) MIB module has eight tables, and it's honestly a whole lineup 👑:
- the MGMD Host Interface Table, which contains one row for each interface on which IGMP or MLD is enabled on a host,
- the MGMD Router Interface Table, which contains one row for each interface on which MGMD is enabled on a router,
- the MGMD Host Cache Table, which contains one row for each IP multicast group that has members on a particular interface on a host,
- the MGMD Router Cache Table, which contains one row for each IP multicast group that has members on a particular interface on a router,
- the reverse MGMD Host Table, which contains one row for each interface that has active multicast groups on a host,
- the reverse MGMD Router Table, which contains one row for each interface that has active multicast groups on a router,
- the MGMD HostSrcList Table, which contains one row for each entry in the source filter record for an interface and multicast group pair on a host, and
- the MGMD RouterSrcList Table, which contains one row for each entry in the source filter record for an interface and multicast group pair on a router.
All tables are meant for EITHER router OR host functionality, as the name and description say. Still, it's expected that some scenarios will have both terms apply to one device. For example, a router that joins a multicast group as a host for measurement purposes 🧐. The source list tables extend the cache tables to show the source-specific includes or excludes tied to each IP multicast group on each specific interface. This only works on IGMPv3- and MLDv2-capable nodes 🦋.
The MGMD MIB tables also include objects for managing IGMP and MLD proxy devices, as described in RFC 4605 [RFC4605]. Proxies are handy in simple topologies where you don't need to run a full multicast routing protocol. A proxy device can make forwarding decisions based on IGMP or MLD group membership activity 💅.
The MIB references the InterfaceIndex and InterfaceIndexOrZero objects defined in RFC 2863 [RFC2863], which is the MIB for generic objects of network interface sub-layers. It also makes extensive references to the InetAddress and InetAddressType objects defined in RFC 4001 [RFC4001] 🌸.
5. Definitions
Here's the MIB module itself, copied exactly as written 🍓. This part ends at the mgmdHostInterfaceIfIndex definition.
MGMD-STD-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, mib-2, Counter32, Gauge32,
Unsigned32, TimeTicks FROM SNMPv2-SMI
InetAddress, InetAddressType FROM INET-ADDRESS-MIB
RowStatus FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF
InterfaceIndexOrZero,
InterfaceIndex FROM IF-MIB;
mgmdStdMIB MODULE-IDENTITY
LAST-UPDATED "200903300000Z" -- March 30, 2009
ORGANIZATION "INTERNET ENGINEERING TASK FORCE MULTICAST and
ANYCAST GROUP MEMBERSHIP Working
Group.
www: http://www.ietf.org/html.charters/magma-charter.html
EMail: magma@ietf.org"
CONTACT-INFO
"Julian Chesterfield
University of Cambridge,
Computer Laboratory,
15 JJ Thompson Avenue,
Cambridge,
CB3 0FD
UK
EMail: julian.chesterfield@cl.cam.ac.uk"
DESCRIPTION
"The MIB module for MGMD management.
A new version of MGMD combining RFC 2933 and RFC 3019.
Includes IGMPv3 and MLDv2 source filtering changes.
Copyright (c) 2009 IETF Trust and the persons
identified as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, are permitted provided that the
following conditions are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials
provided with the distribution.
- Neither the name of Internet Society, IETF or IETF Trust,
nor the names of specific contributors, may be used to endorse
or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This version of this MIB module is part of RFC 5519;
see the RFC itself for full legal notices."
REVISION "200903300000Z" -- March 30, 2009
DESCRIPTION
"This MIB obsoletes both RFC 2933 and RFC 3019."
::= { mib-2 185 }
mgmdMIBObjects OBJECT IDENTIFIER ::= { mgmdStdMIB 1 }
--
-- The MGMD Host Interface Table
--
mgmdHostInterfaceTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdHostInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the interfaces on which
IGMP or MLD is enabled."
::= { mgmdMIBObjects 1 }
mgmdHostInterfaceEntry OBJECT-TYPE
SYNTAX MgmdHostInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) representing an interface on
which IGMP or MLD is enabled."
INDEX { mgmdHostInterfaceIfIndex,
mgmdHostInterfaceQuerierType }
::= { mgmdHostInterfaceTable 1 }
MgmdHostInterfaceEntry ::= SEQUENCE {
mgmdHostInterfaceIfIndex InterfaceIndex,
mgmdHostInterfaceQuerierType InetAddressType,
mgmdHostInterfaceQuerier InetAddress,
mgmdHostInterfaceStatus RowStatus,
mgmdHostInterfaceVersion Unsigned32,
mgmdHostInterfaceVersion1QuerierTimer TimeTicks,
mgmdHostInterfaceVersion2QuerierTimer TimeTicks,
mgmdHostInterfaceVersion3Robustness Unsigned32
}
mgmdHostInterfaceIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The ifIndex value of the interface for which IGMP or MLD is
enabled. The table is indexed by the ifIndex value and the
InetAddressType to allow for interfaces that may be
configured in both IPv4 and IPv6 modes."
::= { mgmdHostInterfaceEntry 1 }okay bestie, we're picking up right where the host interface table left off 🦋 the next few objects are all about what the host knows about its querier and how it talks to the router ✨
mgmdHostInterfaceQuerierType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of this interface. This entry along with
the ifIndex value acts as an index to the mgmdHostInterface
table. A physical interface may be configured in multiple
modes concurrently, e.g., in IPv4 and IPv6 modes connected
to the same interface; however, the traffic is considered
to be logically separate."
::= { mgmdHostInterfaceEntry 2 }
mgmdHostInterfaceQuerier OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The address of the IGMP or MLD Querier on the IP subnet to
which this interface is attached. The InetAddressType,
e.g., IPv4 or IPv6, is identified by the
mgmdHostInterfaceQuerierType variable in the
mgmdHostInterface table."
::= { mgmdHostInterfaceEntry 3 }
mgmdHostInterfaceStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The activation of a row enables the host side of IGMP or
MLD on the interface. The destruction of a row disables
the host side of IGMP or MLD on the interface."
::= { mgmdHostInterfaceEntry 4 }so the querier type is the bit that says "is this an IPv4 or IPv6 row?", and the querier is the address of the IGMP or MLD querier on that subnet 🌸 the row's status is the on/off switch for the host side of IGMP or MLD. activate the row and the host side turns on, destroy it and it turns off. iconic control, no cap 💅
mgmdHostInterfaceVersion OBJECT-TYPE
SYNTAX Unsigned32 (1..3)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum version of MGMD that the host can run on
this interface. A value of 1 is only applicable for IPv4,
and indicates that the host only supports IGMPv1 on the
interface. A value of 2 indicates that the host also
supports IGMPv2 (for IPv4) or MLDv1 (for IPv6). A value of
3 indicates that the host also supports IGMPv3 (for IPv4)
or MLDv2 (for IPv6)."
DEFVAL { 3 }
::= { mgmdHostInterfaceEntry 5 }
mgmdHostInterfaceVersion1QuerierTimer OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the host assumes that there are
no IGMPv1 routers present on the interface. While this is
non-zero, the host will reply to all queries with version 1
membership reports. This variable applies to IGMPv2 or 3
hosts that are forced to run in v1 for compatibility with
v1 routers present on the interface. This object may only
be present when the corresponding value of
mgmdHostInterfaceQuerierType is ipv4."
REFERENCE "RFC 2236, Section 4 and RFC 3376, Section 7.2.1"
DEFVAL { 0 }
::= { mgmdHostInterfaceEntry 6 }
mgmdHostInterfaceVersion2QuerierTimer OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the host assumes that there are
no MGMDv2 routers present on the interface. While this is
non-zero, the host will reply to all queries with version 1
or 2 membership reports. This variable applies to MGMDv3
hosts that are forced to run in v2 for compatibility with
v2 hosts or routers present on the interface."
REFERENCE "RFC 3376, Section 7.2.1 and RFC 3810, Section 8.2.1"
DEFVAL { 0 }
::= { mgmdHostInterfaceEntry 7 }
mgmdHostInterfaceVersion3Robustness OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The robustness variable utilised by an MGMDv3 host in
sending state-change reports for multicast routers. To
ensure the state-change report is not missed, the host
retransmits the state-change report
[mgmdHostInterfaceVersion3Robustness - 1] times. The
variable must be a non-zero value."
REFERENCE "RFC 3376, Section 8.1 and RFC 3810, Section 9.14.1"
DEFVAL { 2 }
::= { mgmdHostInterfaceEntry 8 }the version object is the host's max version, and it's giving "I can go up to this, no higher" 🎀 value 1 is IPv4 only, and 2 and 3 pick up the matching IGMP or MLD versions. the two QuerierTimers are the "how long until I stop assuming there are old routers around" clocks 🧚 and the robustness one controls how many times a state-change report gets resent so it doesn't get lost 🫶 the default is 2 and it has to be non-zero, periodt 💜
--
-- The MGMD Router Interface Table
--
mgmdRouterInterfaceTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdRouterInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the interfaces on which
IGMP or MLD is enabled."
::= { mgmdMIBObjects 2 }
mgmdRouterInterfaceEntry OBJECT-TYPE
SYNTAX MgmdRouterInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) representing an interface on
which IGMP or MLD is enabled."
INDEX { mgmdRouterInterfaceIfIndex,
mgmdRouterInterfaceQuerierType }
::= { mgmdRouterInterfaceTable 1 }
MgmdRouterInterfaceEntry ::= SEQUENCE {
mgmdRouterInterfaceIfIndex InterfaceIndex,
mgmdRouterInterfaceQuerierType InetAddressType,
mgmdRouterInterfaceQuerier InetAddress,
mgmdRouterInterfaceQueryInterval Unsigned32,
mgmdRouterInterfaceStatus RowStatus,
mgmdRouterInterfaceVersion Unsigned32,
mgmdRouterInterfaceQueryMaxResponseTime Unsigned32,
mgmdRouterInterfaceQuerierUpTime TimeTicks,
mgmdRouterInterfaceQuerierExpiryTime TimeTicks,
mgmdRouterInterfaceWrongVersionQueries Counter32,
mgmdRouterInterfaceJoins Counter32,
mgmdRouterInterfaceProxyIfIndex InterfaceIndexOrZero,
mgmdRouterInterfaceGroups Gauge32,
mgmdRouterInterfaceRobustness Unsigned32,
mgmdRouterInterfaceLastMemberQueryInterval Unsigned32,
mgmdRouterInterfaceLastMemberQueryCount Unsigned32,
mgmdRouterInterfaceStartupQueryCount Unsigned32,
mgmdRouterInterfaceStartupQueryInterval Unsigned32
}now we're on the router side 👑 this table is the list of interfaces where IGMP or MLD is turned on, and it's indexed by the ifIndex plus the querier type, so the same physical port can be in IPv4 and IPv6 mode at once 🌈 and the traffic is still logically separate, which is so clean 😭
mgmdRouterInterfaceIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The ifIndex value of the interface for which IGMP or MLD
is enabled. The table is indexed by the ifIndex value and
the InetAddressType to allow for interfaces that may be
configured in both IPv4 and IPv6 modes."
::= { mgmdRouterInterfaceEntry 1 }
mgmdRouterInterfaceQuerierType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of this interface. This entry along with
the ifIndex value acts as the index to the
mgmdRouterInterface table. A physical interface may be
configured in multiple modes concurrently, e.g., in IPv4
and IPv6 modes connected to the same interface; however,
the traffic is considered to be logically separate."
::= { mgmdRouterInterfaceEntry 2 }
mgmdRouterInterfaceQuerier OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The address of the IGMP or MLD Querier on the IP subnet to
which this interface is attached. The InetAddressType,
e.g., IPv4 or IPv6, is identified by the
mgmdRouterInterfaceQuerierType variable in the
mgmdRouterInterface table."
::= { mgmdRouterInterfaceEntry 3 }
mgmdRouterInterfaceQueryInterval OBJECT-TYPE
SYNTAX Unsigned32 (1..31744)
UNITS "seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The frequency at which IGMP or MLD Host-Query packets are
transmitted on this interface."
DEFVAL { 125 }
::= { mgmdRouterInterfaceEntry 4 }
mgmdRouterInterfaceStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The activation of a row enables the router side of IGMP or
MLD on the interface. The destruction of a row disables
the router side of IGMP or MLD on the interface."
::= { mgmdRouterInterfaceEntry 5 }
mgmdRouterInterfaceVersion OBJECT-TYPE
SYNTAX Unsigned32 (1..3)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The version of MGMD that is running on this interface.
Value 1 applies to IGMPv1 routers only. Value 2 applies
to IGMPv2 and MLDv1 routers, and value 3 applies to IGMPv3
and MLDv2 routers.
This object can be used to configure a router capable of
running either version. For IGMP and MLD to function
correctly, all routers on a LAN must be configured to run
the same version on that LAN."
DEFVAL { 3 }
::= { mgmdRouterInterfaceEntry 6 }the ifIndex and querier type are the index pair, and the querier is the one on your subnet 🎀 the query interval is how often Host-Query packets go out (default 125 seconds, the classic 💖). the router status flips the router side on and off the same way the host one does. and the version object is so important: every router on a LAN has to run the same version or things go sideways, so the default is 3 ✨
mgmdRouterInterfaceQueryMaxResponseTime OBJECT-TYPE
SYNTAX Unsigned32 (0..31744)
UNITS "tenths of seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum query response interval advertised in MGMDv2
or IGMPv3 queries on this interface."
REFERENCE "RFC 3810, Section 9.3"
DEFVAL { 100 }
::= { mgmdRouterInterfaceEntry 7 }
mgmdRouterInterfaceQuerierUpTime OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time since mgmdRouterInterfaceQuerier was last
changed."
::= { mgmdRouterInterfaceEntry 8 }
mgmdRouterInterfaceQuerierExpiryTime OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The amount of time remaining before the Other Querier
Present Timer expires. If the local system is the querier,
the value of this object is zero."
::= { mgmdRouterInterfaceEntry 9 }
mgmdRouterInterfaceWrongVersionQueries OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of general queries received whose IGMP or MLD
version does not match the equivalent
mgmdRouterInterfaceVersion, over the lifetime of the row
entry. Both IGMP and MLD require that all routers on a LAN
be configured to run the same version. Thus, if any general
queries are received with the wrong version, this indicates
a configuration error."
::= { mgmdRouterInterfaceEntry 10 }
mgmdRouterInterfaceJoins OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times a group membership has been added on
this interface, that is, the number of times an entry for
this interface has been added to the Cache Table. This
object can give an indication of the amount of activity
between samples over time."
::= { mgmdRouterInterfaceEntry 11 }
mgmdRouterInterfaceProxyIfIndex OBJECT-TYPE
SYNTAX InterfaceIndexOrZero
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Some devices implement a form of IGMP or MLD proxying
whereby memberships learned on the interface represented by
this row cause Host Membership Reports to be sent on the
interface whose ifIndex value is given by this object.
Such a device would implement the mgmdV2RouterBaseMIBGroup
only on its router interfaces (those interfaces with
non-zero mgmdRouterInterfaceProxyIfIndex). Typically, the
value of this object is 0, indicating that no proxying is
being done."
DEFVAL { 0 }
::= { mgmdRouterInterfaceEntry 12 }last bit of this chunk and it's a lot 💀 the max response time is in tenths of seconds (default 100), the uptime and expiry timers are the "who's the querier and how long do they stay" clocks 🧚, and the wrong-version counter is basically the tattletale 🙈 if general queries show up with the wrong version, that's a config error, full stop. the joins counter ticks up every time a group membership gets added to the Cache Table on that interface, so you can watch activity over time 📈 and proxying is the one where memberships on one interface cause Host Membership Reports to go out on another, with 0 meaning no proxying happening 🌸
Okay bestie, the router side of this MIB is where it gets spicy 🔥 Every object here is a knob the router turns to keep track of who's in each multicast group 🧚
Here's the first batch. The group count is read-only, but the Robustness knob is read-create, so you can set it yourself 🎀
mgmdRouterInterfaceGroups OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current number of entries for this interface in the
mgmdRouterCacheTable."
::= { mgmdRouterInterfaceEntry 13 }
mgmdRouterInterfaceRobustness OBJECT-TYPE
SYNTAX Unsigned32 (1..255)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Robustness Variable allows tuning for the expected
packet loss on a subnet. If a subnet is expected to be
lossy, the Robustness Variable may be increased. IGMP and
MLD are robust to (Robustness Variable-1) packet losses."
DEFVAL { 2 }
::= { mgmdRouterInterfaceEntry 14 }Robustness is basically the "my network is kinda flaky" dial 🫶 If the subnet drops packets, you can bump it up. IGMP and MLD are robust to (Robustness Variable-1) packet losses, so the default of 2 covers one lost packet 💅
Next up is the Last Member Query Interval, which is all about leave latency. It's measured in tenths of seconds, and it's irrelevant if the version is 1 🙈
mgmdRouterInterfaceLastMemberQueryInterval OBJECT-TYPE
SYNTAX Unsigned32 (0..31744)
UNITS "tenths of seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Last Member Query Interval is the Max Query Response
Interval inserted into group-specific queries sent in
response to leave group messages, and is also the amount
of time between group-specific query messages. This value
may be tuned to modify the leave latency of the network. A
reduced value results in reduced time to detect the loss of
the last member of a group. The value of this object is
irrelevant if mgmdRouterInterfaceVersion is 1."
DEFVAL { 10 }
::= { mgmdRouterInterfaceEntry 15 }Then come the count and interval objects, which are all read-only. The Last Member Query Count is how many group-specific and group-and-source-specific queries the router sends before it decides there are no local members left. The Startup Query Count and Startup Query Interval cover the burst of queries sent on startup 🌸
mgmdRouterInterfaceLastMemberQueryCount OBJECT-TYPE
SYNTAX Unsigned32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Represents the number of group-specific and group-and-
source-specific queries sent by the router before it assumes
there are no local members."
::= { mgmdRouterInterfaceEntry 16 }
mgmdRouterInterfaceStartupQueryCount OBJECT-TYPE
SYNTAX Unsigned32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Represents the number of Queries sent out on startup,
separated by the Startup Query Interval."
::= { mgmdRouterInterfaceEntry 17 }
mgmdRouterInterfaceStartupQueryInterval OBJECT-TYPE
SYNTAX Unsigned32 (0..31744)
UNITS "seconds"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This variable represents the interval between General
Queries sent by a Querier on startup."
::= { mgmdRouterInterfaceEntry 18 }
--
-- The MGMD Host Cache Table
--
mgmdHostCacheTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdHostCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the IP multicast groups for
which the host is a member on a particular interface."
::= { mgmdMIBObjects 3 }
mgmdHostCacheEntry OBJECT-TYPE
SYNTAX MgmdHostCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the mgmdHostCacheTable."
INDEX { mgmdHostCacheAddressType, mgmdHostCacheAddress,
mgmdHostCacheIfIndex }
::= { mgmdHostCacheTable 1 }
MgmdHostCacheEntry ::= SEQUENCE {
mgmdHostCacheAddressType InetAddressType,
mgmdHostCacheAddress InetAddress ,
mgmdHostCacheIfIndex InterfaceIndex,
mgmdHostCacheUpTime TimeTicks,
mgmdHostCacheLastReporter InetAddress,
mgmdHostCacheSourceFilterMode INTEGER
}
mgmdHostCacheAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the mgmdHostCacheTable entry. This
value applies to both the mgmdHostCacheAddress and the
mgmdHostCacheLastReporter entries."
::= { mgmdHostCacheEntry 1 }
mgmdHostCacheAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information. The InetAddressType, e.g., IPv4 or
IPv6, is identified by the mgmdHostCacheAddressType variable
in the mgmdHostCache table."
::= { mgmdHostCacheEntry 2 }
mgmdHostCacheIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information
for an IP multicast group address."
::= { mgmdHostCacheEntry 3 }
mgmdHostCacheUpTime OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time elapsed since this entry was created."
::= { mgmdHostCacheEntry 4 }
mgmdHostCacheLastReporter OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The IP address of the source of the last membership report
received for this IP multicast group address on this
interface. If no membership report has been received, this
object has a value of 0. The InetAddressType, e.g., IPv4 or
IPv6, is identified by the mgmdHostCacheAddressType variable
in the mgmdHostCache table."
::= { mgmdHostCacheEntry 5 }
mgmdHostCacheSourceFilterMode OBJECT-TYPE
SYNTAX INTEGER {include (1),
exclude (2) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The state in which the interface is currently set. The
value indicates the relevance of the corresponding source
list entries in the mgmdHostSecListTable for MGMDv3
interfaces."
::= { mgmdHostCacheEntry 6 }The host cache is the hosts' own little notebook of which groups they've joined on each interface 📓 Up next is the router cache, which is the router's version of that notebook, and it's packed with timers ⏰
--
-- The MGMD Router Cache Table
--
mgmdRouterCacheTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdRouterCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the IP multicast groups for
which there are members on a particular router interface."
::= { mgmdMIBObjects 4 }
mgmdRouterCacheEntry OBJECT-TYPE
SYNTAX MgmdRouterCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the mgmdRouterCacheTable."
INDEX { mgmdRouterCacheAddressType, mgmdRouterCacheAddress,
mgmdRouterCacheIfIndex }
::= { mgmdRouterCacheTable 1 }
MgmdRouterCacheEntry ::= SEQUENCE {
mgmdRouterCacheAddressType InetAddressType,
mgmdRouterCacheAddress InetAddress,
mgmdRouterCacheIfIndex InterfaceIndex,
mgmdRouterCacheLastReporter InetAddress,
mgmdRouterCacheUpTime TimeTicks,
mgmdRouterCacheExpiryTime TimeTicks,
mgmdRouterCacheExcludeModeExpiryTimer
TimeTicks,
mgmdRouterCacheVersion1HostTimer TimeTicks,
mgmdRouterCacheVersion2HostTimer TimeTicks,
mgmdRouterCacheSourceFilterMode INTEGER
}
mgmdRouterCacheAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the mgmdRouterCacheTable entry. This
value applies to both the mgmdRouterCacheAddress and the
mgmdRouterCacheLastReporter entries."
::= { mgmdRouterCacheEntry 1 }
mgmdRouterCacheAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information. The InetAddressType, e.g., IPv4 or
IPv6, is identified by the mgmdRouterCacheAddressType
variable in the mgmdRouterCache table."
::= { mgmdRouterCacheEntry 2 }
mgmdRouterCacheIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information
for an IP multicast group address."
::= { mgmdRouterCacheEntry 3 }
mgmdRouterCacheLastReporter OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The IP address of the source of the last membership report
received for this IP multicast group address on this
interface. If no membership report has been received, this
object has the value 0. The InetAddressType, e.g., IPv4 or
IPv6, is identified by the mgmdRouterCacheAddressType
variable in the mgmdRouterCache table."
::= { mgmdRouterCacheEntry 4 }
mgmdRouterCacheUpTime OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time elapsed since this entry was created."
::= { mgmdRouterCacheEntry 5 }
mgmdRouterCacheExpiryTime OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This value represents the time remaining before the Group
Membership Interval state expires. The value must always be
greater than or equal to 1."
::= { mgmdRouterCacheEntry 6 }
mgmdRouterCacheExcludeModeExpiryTimer OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This value is applicable only to MGMDv3-compatible nodes
and represents the time remaining before the interface
EXCLUDE state expires and the interface state transitions
to INCLUDE mode. This value can never be greater than
mgmdRouterCacheExpiryTime."
::= { mgmdRouterCacheEntry 7 }
mgmdRouterCacheVersion1HostTimer OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the local router will assume that
there are no longer any MGMD version 1 members on the IP
subnet attached to this interface. This entry only applies
to IGMPv1 hosts, and is not implemented for MLD. Upon
hearing any MGMDv1 Membership Report (IGMPv1 only), this
value is reset to the group membership timer. While this
time remaining is non-zero, the local router ignores any
MGMDv2 Leave messages (IGMPv2 only) for this group that it
receives on this interface."
::= { mgmdRouterCacheEntry 8 }
mgmdRouterCacheVersion2HostTimer OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the local router will assume that
there are no longer any MGMD version 2 members on the IP
subnet attached to this interface. This entry applies to
both IGMP and MLD hosts. Upon hearing any MGMDv2 Membership
Report, this value is reset to the group membership timer.
Assuming no MGMDv1 hosts have been detected, the local
router does not ignore any MGMDv2 Leave messages for this
group that it receives on this interface."
::= { mgmdRouterCacheEntry 9 }
mgmdRouterCacheSourceFilterMode OBJECT-TYPE
SYNTAX INTEGER {include (1),
exclude (2) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current cache state, applicable to MGMDv3-compatible
nodes. The value indicates whether the state is INCLUDE or
EXCLUDE."
::= { mgmdRouterCacheEntry 10 }
--
-- The MGMD Inverse Host interface/cache lookup Table
--Okay bestie, the inverse host table is up first 💖 It's basically a lookup in reverse: instead of asking "which groups does this interface have," it tells you which interfaces are in a given group 🦋
mgmdInverseHostCacheTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdInverseHostCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the interfaces that are
members of a particular group. This is an inverse lookup
table for entries in the mgmdHostCacheTable."
::= { mgmdMIBObjects 5 }
mgmdInverseHostCacheEntry OBJECT-TYPE
SYNTAX MgmdInverseHostCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the
mgmdInverseHostCacheTable."
INDEX { mgmdInverseHostCacheIfIndex,
mgmdInverseHostCacheAddressType,
mgmdInverseHostCacheAddress}
::= { mgmdInverseHostCacheTable 1 }
MgmdInverseHostCacheEntry ::= SEQUENCE {
mgmdInverseHostCacheIfIndex InterfaceIndex,
mgmdInverseHostCacheAddressType InetAddressType,
mgmdInverseHostCacheAddress InetAddress
}
mgmdInverseHostCacheIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information."
::= { mgmdInverseHostCacheEntry 1 }
mgmdInverseHostCacheAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the mgmdInverseHostCacheTable entry."
::= { mgmdInverseHostCacheEntry 2 }
mgmdInverseHostCacheAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information about an interface. The
InetAddressType, e.g., IPv4 or IPv6, is identified by the
mgmdInverseHostCacheAddressType variable in the
mgmdInverseHostCache table."
::= { mgmdInverseHostCacheEntry 3 }Now the router side, which is the mirror image of the host one but looks at the router's cache instead ✨ Same vibe, different table 🎀
--
-- The MGMD Inverse Router interface/cache lookup Table
--
mgmdInverseRouterCacheTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdInverseRouterCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the interfaces that
are members of a particular group. This is an inverse
lookup table for entries in the mgmdRouterCacheTable."
::= { mgmdMIBObjects 6 }
mgmdInverseRouterCacheEntry OBJECT-TYPE
SYNTAX MgmdInverseRouterCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the
mgmdInverseRouterCacheTable."
INDEX { mgmdInverseRouterCacheIfIndex,
mgmdInverseRouterCacheAddressType,
mgmdInverseRouterCacheAddress }
::= { mgmdInverseRouterCacheTable 1 }
MgmdInverseRouterCacheEntry ::= SEQUENCE {
mgmdInverseRouterCacheIfIndex InterfaceIndex,
mgmdInverseRouterCacheAddressType InetAddressType,
mgmdInverseRouterCacheAddress InetAddress
}
mgmdInverseRouterCacheIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information
for an IP multicast group address."
::= { mgmdInverseRouterCacheEntry 1 }
mgmdInverseRouterCacheAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the mgmdInverseRouterCacheTable entry."
::= { mgmdInverseRouterCacheEntry 2 }
mgmdInverseRouterCacheAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information. The InetAddressType, e.g., IPv4 or
IPv6, is identified by the mgmdInverseRouterCacheAddressType
variable in the mgmdInverseRouterCache table."
::= { mgmdInverseRouterCacheEntry 3 }Next up is the host source list, which is where it gets a little spicy 🔥 Each row is keyed by address type, group, interface, and host address, so you can track exactly who's asking for what 🫶
--
-- The MGMD Host Source list Table
--
mgmdHostSrcListTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdHostSrcListEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the Source List entries
corresponding to each interface and multicast group pair
on a host."
::= { mgmdMIBObjects 7 }
mgmdHostSrcListEntry OBJECT-TYPE
SYNTAX MgmdHostSrcListEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the mgmdHostSrcListTable."
INDEX { mgmdHostSrcListAddressType, mgmdHostSrcListAddress,
mgmdHostSrcListIfIndex, mgmdHostSrcListHostAddress }
::= { mgmdHostSrcListTable 1 }
MgmdHostSrcListEntry ::= SEQUENCE {
mgmdHostSrcListAddressType InetAddressType,
mgmdHostSrcListAddress InetAddress,
mgmdHostSrcListIfIndex InterfaceIndex,
mgmdHostSrcListHostAddress InetAddress,
mgmdHostSrcListExpire TimeTicks
}
mgmdHostSrcListAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the InetAddress variables in this
table. This value applies to the mgmdHostSrcListHostAddress
and mgmdHostSrcListAddress entries."
::= { mgmdHostSrcListEntry 1 }
mgmdHostSrcListAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information."
::= { mgmdHostSrcListEntry 2 }
mgmdHostSrcListIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information
for an IP multicast group address."
::= { mgmdHostSrcListEntry 3 }
mgmdHostSrcListHostAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The host address to which this entry corresponds. The
mgmdHostCacheSourceFilterMode value for this group address
and interface indicates whether this host address is
included or excluded."
::= { mgmdHostSrcListEntry 4 }
mgmdHostSrcListExpire OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This value indicates the relevance of the SrcList entry,
whereby a non-zero value indicates this is an INCLUDE state
value, and a zero value indicates this to be an EXCLUDE
state value."
::= { mgmdHostSrcListEntry 5 }Last bit of this chunk is the router source list, which is basically the host one's twin but living on the router side 🧚 It has the same INCLUDE and EXCLUDE vibes, so it's giving déjà vu 💅
--
-- The MGMD Router Source list Table
--
mgmdRouterSrcListTable OBJECT-TYPE
SYNTAX SEQUENCE OF MgmdRouterSrcListEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the Source List entries
corresponding to each interface and multicast group pair on
a Router."
::= { mgmdMIBObjects 8 }
mgmdRouterSrcListEntry OBJECT-TYPE
SYNTAX MgmdRouterSrcListEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the mgmdRouterSrcListTable."
INDEX { mgmdRouterSrcListAddressType,
mgmdRouterSrcListAddress,
mgmdRouterSrcListIfIndex,
mgmdRouterSrcListHostAddress }
::= { mgmdRouterSrcListTable 1 }
MgmdRouterSrcListEntry ::= SEQUENCE {
mgmdRouterSrcListAddressType InetAddressType,
mgmdRouterSrcListAddress InetAddress,
mgmdRouterSrcListIfIndex InterfaceIndex,
mgmdRouterSrcListHostAddress InetAddress,
mgmdRouterSrcListExpire TimeTicks
}
mgmdRouterSrcListAddressType OBJECT-TYPE
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The address type of the InetAddress variables in this
table. This value applies to the
mgmdRouterSrcListHostAddress and mgmdRouterSrcListAddress
entries."
::= { mgmdRouterSrcListEntry 1 }
mgmdRouterSrcListAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information."
::= { mgmdRouterSrcListEntry 2 }
mgmdRouterSrcListIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information
for an IP multicast group address."
::= { mgmdRouterSrcListEntry 3 }
mgmdRouterSrcListHostAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE(4|16))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The host address to which this entry corresponds. The
mgmdRouterCacheSourceFilterMode value for this group address
and interface indicates whether this host address is
included or excluded."
::= { mgmdRouterSrcListEntry 4 }
mgmdRouterSrcListExpire OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This value indicates the relevance of the SrcList entry,
whereby a non-zero value indicates this is an INCLUDE state
value, and a zero value indicates this to be an EXCLUDE
state value."
::= { mgmdRouterSrcListEntry 5 }Now we're getting into conformance, which is the part where the MIB spells out what an implementation has to support 🌈 Here's the start of the conformance block, with the IGMPv1 host compliance statement ✨
-- conformance information
mgmdMIBConformance OBJECT IDENTIFIER ::= { mgmdStdMIB 2 }
mgmdMIBCompliance OBJECT IDENTIFIER ::= { mgmdMIBConformance 1 }
mgmdMIBGroups OBJECT IDENTIFIER ::= { mgmdMIBConformance 2 }
-- Protocol Version Conformance
-- Read Compliance statement for IGMPv1 Hosts
-- IGMPv1 only supports the IPv4 Address Family
mgmdIgmpV1HostReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-only compliance statement for hosts running IGMPv1
[RFC1112] and implementing the MGMD MIB. IGMPv1 hosts must
support the IPv4 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdHostBaseMIBGroup }
OBJECT mgmdHostInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdHostInterfaceVersion
SYNTAX Unsigned32 (1)
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required. Only version 1 needs to be
supported."
GROUP mgmdHostExtendedMIBGroup
DESCRIPTION
"Supporting this group can be especially useful in
an environment with a router that does not support the
MGMD MIB."
::= { mgmdMIBCompliance 1 }
-- Read Compliance statement for IGMPv1 Routers
-- IGMPv1 only supports the IPv4 Address FamilyOkay bestie, we're picking up right where the IGMPv1 router read statement starts, so let's go 🦋✨
Here's the read-only compliance statement for IGMPv1 routers. It's giving "IPv4 or bust" 💅
mgmdIgmpV1RouterReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-only compliance statement for routers running
IGMPv1 [RFC1112] and implementing the MGMD MIB. IGMPv1
routers only support the IPv4 address type.
Non-accessible index objects that only need IPv4
support are:
OBJECT mgmdRouterCacheAddressType
SYNTAX InetAddressType { ipv4(1) }
OBJECT mgmdRouterCacheAddress
SYNTAX InetAddress (SIZE(4))
OBJECT mgmdRouterInterfaceQuerierType
SYNTAX InetAddressType { ipv4(1) }
OBJECT mgmdInverseRouterCacheAddressType
SYNTAX InetAddressType { ipv4(1) }
"
MODULE -- this module
MANDATORY-GROUPS { mgmdRouterBaseMIBGroup }
OBJECT mgmdRouterCacheLastReporter
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"IGMPv1 routers only support IPv4 addresses."
OBJECT mgmdRouterInterfaceQuerier
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"IGMPv1 routers only support IPv4 addresses."
OBJECT mgmdInverseRouterCacheAddress
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"IGMPv1 routers only support IPv4 addresses."
OBJECT mgmdRouterInterfaceVersion
SYNTAX Unsigned32 (1)
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required. Only version 1 needs to
be supported."
OBJECT mgmdRouterInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdRouterInterfaceQueryInterval
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { mgmdMIBCompliance 2 }Now the write version for IGMPv1 routers, which is the same vibe but with read-create energy ✍️🎀
-- Write Compliance statement for IGMPv1 Routers
-- IGMPv1 only supports the IPv4 Address Family
mgmdIgmpV1RouterWriteMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-create compliance statement for routers running
IGMPv1 [RFC1112] and implementing the MGMD MIB. IGMPv1
routers only support the IPv4 address type.
Non-accessible index objects that only need IPv4
support are:
OBJECT mgmdRouterCacheAddressType
SYNTAX InetAddressType { ipv4(1) }
OBJECT mgmdRouterCacheAddress
SYNTAX InetAddress (SIZE(4))
OBJECT mgmdRouterInterfaceQuerierType
SYNTAX InetAddressType { ipv4(1) }
OBJECT mgmdInverseRouterCacheAddressType
SYNTAX InetAddressType { ipv4(1) }
"
MODULE -- this module
MANDATORY-GROUPS { mgmdRouterBaseMIBGroup }
OBJECT mgmdRouterCacheLastReporter
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"Only IPv4 addresses needed for IGMPv1 router support."
OBJECT mgmdRouterInterfaceQuerier
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"Only IPv4 addresses needed for IGMPv1 router support."
OBJECT mgmdInverseRouterCacheAddress
SYNTAX InetAddress (SIZE(4))
DESCRIPTION
"Only IPv4 addresses needed for IGMPv1 router support."
OBJECT mgmdRouterInterfaceVersion
SYNTAX Unsigned32 (1)
DESCRIPTION
"Write access is not required. Only version 1 needs to
be supported."
::= { mgmdMIBCompliance 3 }Next up is the read-only statement for hosts running IGMPv2 or MLDv1. Two protocols, two address families, one vibe 🌈
-- Read Compliance statement for IGMPv2 and MLDv1 Hosts
-- IGMPv2 only supports the IPv4 Address Family
-- MLDv1 only supports the IPv6 Address Family
mgmdIgmpV2MldV1HostReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-only compliance statement for hosts running IGMPv2
[RFC2236] or MLDv1 [RFC2710] and implementing the MGMD
MIB. IGMPv2 hosts only support the IPv4 address type and
MLDv1 hosts only support the IPv6 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdHostBaseMIBGroup,
mgmdV2HostMIBGroup
}
OBJECT mgmdHostInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdHostInterfaceVersion
SYNTAX Unsigned32 (1..2)
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required. Only versions 1 and 2 need
to be supported."
GROUP mgmdHostExtendedMIBGroup
DESCRIPTION
"Supporting this group can be especially useful in an
environment with a router that does not support the
MGMD MIB."
::= { mgmdMIBCompliance 4 }And the write version for those same hosts, which is lowkey simpler 🍓
-- Write Compliance statement for IGMPv2 and MLDv1 Hosts
-- IGMPv2 only supports the IPv4 Address Family
-- MLDv1 only supports the IPv6 Address Family
mgmdIgmpV2MldV1HostWriteMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-create compliance statement for hosts running
IGMPv2 [RFC2236] or MLDv1 [RFC2710] and implementing
the MGMD MIB. IGMPv2 hosts only support the IPv4 address
type and MLDv1 hosts only support the IPv6 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdHostBaseMIBGroup,
mgmdV2HostMIBGroup }
OBJECT mgmdHostInterfaceVersion
SYNTAX Unsigned32 (1..2)
DESCRIPTION
"Only versions 1 and 2 need to be supported."
::= { mgmdMIBCompliance 5 }Okay, now the read-only statement for routers running IGMPv2 or MLDv1. This one has a bunch of read-only objects, so it's a whole vibe 👑
-- Read Compliance statement for IGMPv2 and MLDv1 Routers
-- IGMPv2 only supports the IPv4 Address Family
-- MLDv1 only supports the IPv6 Address Family
mgmdIgmpV2MldV1RouterReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-only compliance statement for routers running
IGMPv2 [RFC2236] or MLDv1 [RFC2710] and implementing
the MGMD MIB. IGMPv2 routers only support the IPv4
address type and MLDv1 routers only support the IPv6
address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdRouterBaseMIBGroup,
mgmdV2RouterBaseMIBGroup
}
OBJECT mgmdRouterInterfaceLastMemberQueryInterval
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceRobustness
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceQueryMaxResponseTime
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceVersion
SYNTAX Unsigned32 (1..2)
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required. Only versions 1 and 2
need to be supported."
OBJECT mgmdRouterInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdRouterInterfaceQueryInterval
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
GROUP mgmdV2ProxyMIBGroup
DESCRIPTION
"Write access is not required."
::= { mgmdMIBCompliance 6 }The write statement for routers covers four protocols at once: IGMPv2, IGMPv3, MLDv1, and MLDv2. It's a whole squad 🧚
-- Write Compliance statement for IGMPv2, IGMPv3, MLDv1, and MLDv2
-- Routers
-- IGMPv2 and IGMPv3 only support the IPv4 Address Family
-- MLDv1 and MLDv2 only support the IPv6 Address Family
mgmdIgmpV2V3MldV1V2RouterWriteMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-create compliance statement for routers running
IGMPv2 [RFC2236], IGMPv3 [RFC3376], MLDv1 [RFC2710], or
MLDv2 [RFC3810] and implementing the MGMD MIB. IGMPv2 and
IGMPv3 routers only support the IPv4 address type, while
MLDv1 and MLDv2 routers only support the IPv6 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdRouterBaseMIBGroup,
mgmdV2RouterBaseMIBGroup
}
GROUP mgmdV2ProxyMIBGroup
DESCRIPTION
"Read-create access is required."
::= { mgmdMIBCompliance 7 }Next are the read-only statements for hosts running IGMPv3 or MLDv2. Same four-protocol energy, but on the host side 🫶
-- Read Compliance statement for IGMPv2, IGMPv3, MLDv1, and MLDv2 Hosts
-- IGMPv2 and IGMPv3 only support the IPv4 Address Family
-- MLDv1 and MLDv2 only support the IPv6 Address Family
mgmdIgmpV3MldV2HostReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for hosts running IGMPv3
[RFC3376] or MLDv2 [RFC3810] and implementing the
MGMD MIB. IGMPv3 hosts only support the IPv4 address
type and MLDv2 hosts only support the IPv6 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdHostBaseMIBGroup,
mgmdV2HostMIBGroup,
mgmdV3HostMIBGroup
}
OBJECT mgmdHostInterfaceVersion
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdHostInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdHostInterfaceVersion3Robustness
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
GROUP mgmdHostExtendedMIBGroup
DESCRIPTION
"Supporting this group can be especially useful in
an environment with a router that does not support the
MGMD MIB."
::= { mgmdMIBCompliance 8 }Then the write version for those hosts 💜
-- Write Compliance statement for IGMPv2, IGMPv3, MLDv1, and MLDv2 Hosts
-- IGMPv2 and IGMPv3 only support the IPv4 Address Family
-- MLDv1 and MLDv2 only support the IPv6 Address Family
mgmdIgmpV3MldV2HostWriteMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for hosts running IGMPv3
[RFC3376] or MLDv2 [RFC3810] and implementing the
MGMD MIB. IGMPv3 hosts only support the IPv4 address
type and MLDv2 hosts only support the IPv6 address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdHostBaseMIBGroup,
mgmdV2HostMIBGroup,
mgmdV3HostMIBGroup
}
GROUP mgmdHostExtendedMIBGroup
DESCRIPTION
"Supporting this group can be especially useful in
an environment with a router that does not support the
MGMD MIB."
::= { mgmdMIBCompliance 9 }And we're ending on the header for the next read-only router statement, the one for IGMPv2, IGMPv3, MLDv1, and MLDv2 routers. Stay tuned, it's about to get good 👀
-- Read Compliance statement for IGMPv2, IGMPv3, MLDv1, and MLDv2
-- Routers
-- IGMPv2 and IGMPv3 only support the IPv4 Address Family
-- MLDv1 and MLDv2 only support the IPv6 Address FamilymgmdIgmpV3MldV2RouterReadMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"A read-only compliance statement for routers running
IGMPv3 [RFC3376] or MLDv2 [RFC3810] and implementing
the MGMD MIB. IGMPv3 routers only support the IPv4
address type and MLDv2 routers only support the IPv6
address type."
MODULE -- this module
MANDATORY-GROUPS { mgmdRouterBaseMIBGroup,
mgmdV2RouterBaseMIBGroup,
mgmdV3RouterMIBGroup
}
OBJECT mgmdRouterInterfaceLastMemberQueryInterval
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceRobustness
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceQueryMaxResponseTime
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceVersion
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT mgmdRouterInterfaceStatus
SYNTAX RowStatus {active(1)}
MIN-ACCESS read-only
DESCRIPTION
"Read-write or read-create access is not required and only
the value 'active(1)' needs to be supported."
OBJECT mgmdRouterInterfaceQueryInterval
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
GROUP mgmdV2ProxyMIBGroup
DESCRIPTION
"Write access is not required."
::= { mgmdMIBCompliance 10 }
-- units of conformance
mgmdHostBaseMIBGroup OBJECT-GROUP
OBJECTS { mgmdHostInterfaceStatus,
mgmdHostInterfaceVersion
}
STATUS current
DESCRIPTION
"The basic collection of objects providing management of
MGMD version 1, 2, or 3 for hosts."
::= { mgmdMIBGroups 1 }
mgmdRouterBaseMIBGroup OBJECT-GROUP
OBJECTS { mgmdRouterInterfaceStatus,
mgmdRouterInterfaceQueryInterval,
mgmdRouterCacheUpTime, mgmdRouterCacheExpiryTime,
mgmdRouterInterfaceVersion,
mgmdRouterInterfaceJoins, mgmdRouterInterfaceGroups,
mgmdRouterCacheLastReporter,
mgmdRouterInterfaceQuerierUpTime,
mgmdRouterInterfaceQuerierExpiryTime,
mgmdRouterInterfaceQuerier,
mgmdInverseRouterCacheAddress
}
STATUS current
DESCRIPTION
"The basic collection of objects providing management of
MGMD version 1, 2, or 3 for routers."
::= { mgmdMIBGroups 2 }
mgmdV2HostMIBGroup OBJECT-GROUP
OBJECTS { mgmdHostInterfaceVersion1QuerierTimer
}
STATUS current
DESCRIPTION
"A collection of additional read-only objects for management
of IGMP version 2 in hosts for MGMD version 2 compliance."
::= { mgmdMIBGroups 3 }
mgmdHostExtendedMIBGroup OBJECT-GROUP
OBJECTS { mgmdHostCacheLastReporter, mgmdHostCacheUpTime,
mgmdHostInterfaceQuerier, mgmdInverseHostCacheAddress }
STATUS current
DESCRIPTION
"A collection of optional objects for MGMD hosts."
::= { mgmdMIBGroups 4 }
mgmdV2RouterBaseMIBGroup OBJECT-GROUP
OBJECTS { mgmdRouterInterfaceWrongVersionQueries,
mgmdRouterInterfaceLastMemberQueryCount,
mgmdRouterInterfaceStartupQueryCount,
mgmdRouterInterfaceStartupQueryInterval,
mgmdRouterCacheVersion1HostTimer,
mgmdRouterInterfaceQueryMaxResponseTime,
mgmdRouterInterfaceRobustness,
mgmdRouterInterfaceLastMemberQueryInterval
}
STATUS current
DESCRIPTION
"A collection of additional read-only objects for
management of MGMD version 2 in routers."
::= { mgmdMIBGroups 5 }
mgmdV2ProxyMIBGroup OBJECT-GROUP
OBJECTS { mgmdRouterInterfaceProxyIfIndex }
STATUS current
DESCRIPTION
"A collection of additional read-create objects for
management of MGMD proxy devices."
::= { mgmdMIBGroups 6 }
mgmdV3HostMIBGroup OBJECT-GROUP
OBJECTS { mgmdHostInterfaceVersion2QuerierTimer,
mgmdHostCacheSourceFilterMode,
mgmdHostInterfaceVersion3Robustness,
mgmdHostSrcListExpire
}
STATUS current
DESCRIPTION
"A collection of additional objects for
management of MGMD version 3 in hosts."
::= { mgmdMIBGroups 7 }
mgmdV3RouterMIBGroup OBJECT-GROUP
OBJECTS { mgmdRouterCacheSourceFilterMode,
mgmdRouterCacheVersion2HostTimer,
mgmdRouterCacheExcludeModeExpiryTimer,
mgmdRouterSrcListExpire
}
STATUS current
DESCRIPTION
"A collection of additional read-only objects for
management of MGMD version 3 in routers."
::= { mgmdMIBGroups 8 }
END6. Security Considerations 🔒
Okay, bestie, this part is serious 🥺 There are a bunch of management objects in this MIB module with a MAX-ACCESS of read-write and/or read-create. Those objects can be sensitive or vulnerable depending on the network, and SET operations in a non-secure environment, without proper protection, can seriously mess up network operations 💀 Here are the tables and objects and how sensitive or vulnerable they are:
- The
mgmdRouterInterfaceTablegives read-create access to 2 values:mgmdRouterInterfaceStatusandmgmdRouterInterfaceQueryInterval.mgmdRouterInterfaceStatuslets a remote user enable or disable multicast support on a router interface, so it's a significant denial-of-service vulnerability 🚨mgmdRouterInterfaceQueryIntervalcontrols how often host-query packets get sent. That's less of a vulnerability, but it still needs secure access control 🔐 - The
mgmdRouterCacheTablealso gives access to read-create objects.mgmdRouterInterfaceVersioncontrols the protocol conformance of an interface, so it's a potential denial-of-service vulnerability 😬mgmdRouterInterfaceQueryMaxResponseTime,mgmdRouterInterfaceRobustness, andmgmdRouterInterfaceLastMemberQueryIntervalare all tuning parameters for the characteristics of host-query packets. Messing with them can be disruptive to local multicast communication 🌸 - The
mgmdHostInterfaceTablegives a read-create object,mgmdHostInterfaceVersion3Robustness, which controls how robust the interface is to packet loss. Disabling robustness when packets are getting lost could cause denial of service to hosts. In general though, this is a low risk 🦋
Real talk: SNMP versions before SNMPv3 did not have adequate security 🙈 Even if the network itself is secure (for example, by using IPsec), there's no control over who on that secure network gets to access and GET/SET (read/change/create/delete) the objects in this MIB module. Not it! 💅
It is RECOMMENDED that implementers consider the security features provided by the SNMPv3 framework (see [RFC3410], section 8), including full support for the SNMPv3 cryptographic mechanisms (for authentication and privacy) 🔐✨
Further, deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED 🚫 Instead, it is RECOMMENDED to deploy SNMPv3 and to enable cryptographic security. It's then a customer/operator responsibility to make sure the SNMP entity giving access to an instance of this MIB module is configured so the objects are only accessible to principals (users) with legitimate rights to GET or SET (change/create/delete) them. Lock it down, babe 🔒👑
7. IANA Considerations 🌈
This MIB introduces a new term for two existing multicast protocols: Multicast Group Membership Discovery. It covers both the IPv4 multicast discovery protocol, IGMP, and the IPv6 multicast discovery protocol, MLD, as defined in RFCs 2933 [RFC2933] and 3019 [RFC3019], respectively 🧚
The MIB module in this document uses the following IANA-assigned OBJECT IDENTIFIER value recorded in the SMI Numbers registry:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
mgmdStdMIB { mib-2 185 }8. Contributors 🫶
The authors of RFC 2933 [RFC2933] and RFC 3019 [RFC3019], which this document is derived from, are:
- Keith McCloghrie
- Dino Farinacci
- Dave Thaler
- Brian Haberman
- Randy Worzella
9. Acknowledgements 💖
Special thanks to James Lingard, Bill Fenner, and Dave Thaler for detailed comments on the MIB 🙌
Bert Wijnen deserves special recognition for his exhaustive reviews and constructive feedback on SNMP and SMI issues related to this MIB 👑
10. References 📚
10.1. Normative References
[RFC1112] Deering, S., "Host extensions for IP multicasting", STD 5,
RFC 1112, August 1989.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2236] Fenner, W., "Internet Group Management Protocol, Version
2", RFC 2236, November 1997.
[RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.
[RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast
Listener Discovery (MLD) for IPv6", RFC 2710,
October 1999.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB", RFC 2863, June 2000.
[RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
Thyagarajan, "Internet Group Management Protocol, Version
3", RFC 3376, October 2002.
[RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery
Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.
[RFC4001] Daniele, M., Haberman, B., Routhier, S., and J.
Schoenwaelder, "Textual Conventions for Internet Network
Addresses", RFC 4001, February 2005.10.2. Informative References
[RFC2933] McCloghrie, K., Farinacci, D., and D. Thaler, "Internet
Group Management Protocol MIB", RFC 2933, October 2000.
[RFC3019] Haberman, B. and R. Worzella, "IP Version 6 Management
Information Base for The Multicast Listener Discovery
Protocol", RFC 3019, January 2001.
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.
[RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick,
"Internet Group Management Protocol (IGMP) / Multicast
Listener Discovery (MLD)-Based Multicast Forwarding
("IGMP/MLD Proxying")", RFC 4605, August 2006.Authors' Addresses 🦋
Julian Chesterfield
University of Cambridge
15 JJ Thompson Avenue
Cambridge CB3 0FD
UK
EMail: julian.chesterfield@cl.cam.ac.uk
Brian Haberman (editor)
Johns Hopkins University / Applied Physics Laboratory
11100 Johns Hopkins Road
Laurel, MD 20723
USA
EMail: brian@innovationslab.net📦 where this page comes from
- ietf: rfc5519 2009-04
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms