Maximum name length of 63 characters respected these days?

[DanielOaks]

RFCs say server names and hostnames can only be a max of 63 characters, do servers actually respect that these days or do they allow longer names?

Related, is there an RPL_ISUPPORT token that specifies HOSTLEN or something (I think mammon may have proposed one, check out irc-defs lists).

[euank]

Just for an n=1, the below is what inspircd has.

Ref: inspircd/inspircd@f2db4b7

Notice that that commit is on master, but not included in any tags (¯_(ツ)_/¯)

Recent released versions of inspircd have 64 as the max in most places, and 63 in chghost, but after that change will have 64 everywhere by default (+ configuration possible).

Back in ancient times (v1 era) the maximum was bumped up from 63 to 64 for user hostnames (for some reason).

inspircd doesn't include HOSTLEN in its ISUPPORT.

[DanielOaks]

Awesome, that's really interesting. Thanks for looking into it, it's much appreciated.

It doesn't look like HOSTLEN is actually used, but fits the style of most other *LEN tokens so I kinda expected it to be out there honestly (especially since hostname lengths are flexible these days, or at least I think some like Freenode can be longer than 63/64).

[ailin-nemui]

some clients will split messages to keep within 510 bytes based on a hard-coded assumed 63: https://github.com/irssi/irssi/blob/master/src/irc/core/irc-servers.c#L62

[dequis]

RFCs say server names and hostnames can only be a max of 63 characters, do servers actually respect that these days or do they allow longer names?

A long time ago I got an absurdly long rnds and tried to connect to espernet (charybdis), when it was over 63 or 64 chars it showed a warning on the login notices saying that it ignored the rdns and showed the IP address instead.