VLAN-INTERFACES(5)

✨ VLAN-INTERFACES ✨ (that's the vlan manpage bestie 💅)

okay so this is the manual page for vlan — it's a file format page, sitting at section 5, and it's all about the vlan glow-up for /etc/network/interfaces. 🦋

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🌸 NAME 🌸

/etc/network/interfaces (vlan) — the vlan extensions for the interfaces(5) file format. that's it, that's the name, no notes. 💖

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💫 DESCRIPTION 💫

/etc/network/interfaces is where all the network interface configuration lives, and it's what ifup(8) and ifdown(8) read when they do their thing. ✨

this page is specifically about the vlan extensions to the standard interfaces(5) format. not the whole format, just the vlan part. iykyk. 🎀

so there's two kinds of extensions going on here:

• primary extensions — these make vlan interfaces and destroy vlan interfaces. the main characters. 👑
• secondary extensions — these do ipv4 interface manipulation, and you lowkey generally need them when you're running (a lot of) vlans.

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🧚 VLAN CREATION 🧚

a vlan interface definition is made of two things: the vlan interface name, and an optional raw-device parameter. that's the whole recipe bestie. 🍓

vlan interfaces are numbered 1 to 4095. ⭐

and here's the fun part — you get to choose how your interface names look: you can have them zero-padded to 4 numbers, or just the plain digits with no leading zero. both are valid, they just give you different names.

the following example shows four ways to create a vlan with id 1 on interface eth0. and no cap — they all result in different names. 💀

 iface eth0.1 inet static
      address 192.168.1.1
      netmask 255.255.255.0

 iface vlan1 inet static
      vlan-raw-device eth0
      address 192.168.1.1
      netmask 255.255.255.0

 iface eth0.0001 inet static
      address 192.168.1.1
      netmask 255.255.255.0

 iface vlan0001 inet static
      vlan-raw-device eth0
      address 192.168.1.1
      netmask 255.255.255.0

 # We don't have br support out of the box
 iface br0.2 inet static
      vlan-raw-device br0
      address 192.168.1.1
      netmask 255.255.255.0

 # Aliases are ignored
 iface br0.2:1 inet static
      address 192.168.1.1
      netmask 255.255.255.255

see how eth0.1 and vlan1 and eth0.0001 and vlan0001 are all the same vlan id but four totally different names? that's the zero-padding situation right there. 🫶

also peep the comments: no br support out of the box, and aliases are ignored. noted. 📝

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💅 EXTRA IFACE OPTIONS 💅

usually if you're out here using vlans, you also wanna do some other little manipulations with the ip stack or the interface. relatable honestly. so here's the extra options:

• vlan-raw-device devicename — tells it which device to create the vlan on. ⚠️ this one gets ignored when the devicename is already part of the vlan interface name. so if it's in the name, you don't need to say it again.
• ip-proxy-arp 0|1 — turns proxy-arp off (0) or on (1) for this specific interface. and yes bestie, this also works on plain ethernet-like devices. ✨
• ip-rp-filter 0|1|2 — sets the return path filter for this specific interface. same deal, this also works on plain ethernet-like devices. 🌈
• hw-mac-address mac-address — this sets the mac address of the interface before bringing it up. works on any device that lets you set the hardware address with the ip command. 🔥

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🎀 AUTHOR 🎀

this manpage was adapted from interfaces(5) by Ard van Breemen <ard@kwaak.net> — shoutout to them, real ones. 💜

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🔍 SEE ALSO 🔍

• vconfig(8)
• interfaces(5)

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💖 and that's the whole page bestie, you ate it. go forth and vlan responsibly. 💅✨

so this page is from the vlan manual and it's dated September 30 2007 — yeah it's giving vintage but it still serves. mwah. 🎀🦋🌸