YPSERV.CONF(5)

📦
version 4.2 · 3 versions
, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 ypserv.conf — the vibe guide 💖

okay bestie, listen up: this is the manual page for YPSERV.CONF(5) from the NIS Reference Manual, and it's literally the config file glow-up for ypserv and rpc.ypxfrd. it's giving "small file, big responsibilities". let's get into it 🫶

✨ NAME ✨

ypserv.conf — configuration file for ypserv and rpc.ypxfrd

🌸 DESCRIPTION 🌸

ypserv.conf is an ASCII file, and it's holding two whole jobs at once: it's got some options for ypserv, and it's also got a list of rules for special host and map access, for both ypserv and rpc.ypxfrd. the way this file gets read by ypserv and rpc.ypxfrd at startup, or when they receive a SIGHUP signal? iconic behaviour tbh.

one entry per line, no exceptions. if the line is an option line, the format is:

option: argument

and the line for an access rule has the format:

host:domain:map:security

all rules are tried one by one. and if no match is found, access to a map is allowed. periodt.

🎀 the options that exist 🎀

  • files: 30 — this one says how many database files should be cached by ypserv. if you set 0, caching is disabled. heads up though: decreasing this number is only possible if ypserv is restarted. no sneaky live edits 💅
  • trusted_master: server — if you set this on a slave server, new maps from the host server will be accepted as master. the default is that no trusted master is set, and new maps will not be accepted. it's giving trust issues, and honestly, valid.

example:

trusted_master: ypmaster.example.org
  • slp: [yes|<no>|domain] — if this option is enabled and SLP support is compiled in, the NIS server registers itself on a SLP server. if the variable is set to domain, an attribute domain with a comma seperated list of supported domainnames is set. else, that attribute will not be set. the default is "no" (disabled).
  • xfr_check_port: [<yes>|no] — with this option enabled, the NIS master server have to run on a port < 1024. the default is "yes" (enabled).

🦋 the access rule fields, explained 🦋

  • host — IPv4 only address. wildcards are allowed. but bestie… these rules are ignored for IPv6, which means it's better to not use this option at all anymore. lowkey deprecated energy 😭

examples:

131.234. = 131.234.0.0/255.255.0.0
131.234.214.0/255.255.254.0
  • domain — specifies the domain for which this rule should be applied. an asterix as a wildcard is allowed. yes, it's spelled asterix, that's what the page says, we don't edit ✨
  • map — name of the map, or asterisk for all maps.
  • security — one of none, port, deny:
    • none — always allow access. generous queen 👑
    • port — allow access if from port < 1024. otherwise, do not allow access.
    • deny — deny access to this map. not me being the bouncer 💀

📁 FILES 📁

  • /etc/ypserv.conf

👀 SEE ALSO 👀

⚠️ WARNINGS ⚠️

the access rules for special maps are no real improvement in security, but they make the life a little bit harder for a potential hacker. so like, it's a speed bump, not a fortress, okay?
Solaris clients don't use privileged ports. all security options which depend on privileged ports cause big problems on Solaris clients. this one is not a drill 🚨

💜 AUTHOR 💜

Thorsten Kukuk <kukuk@thkukuk.de>

and that's the whole page, bestie!! this was the NIS Reference Manual version dated 03/04/2016, and you just ate the entire YPSERV.CONF(5) page, no crumbs left 🌈💖 slay, go configure something. mwah 🎀

📦 where this page comes from