topic Re: hostname length in Operating System - HP-UX

hostname length

Mauro Gatti — Tue, 13 Jan 2004 04:13:31 GMT

Hi all, could You explain to me if there is any limit to hostname lenght?
Which problem types can I find using a long hostname?

Thank You

Re: hostname length

Robert-Jan Goossens — Tue, 13 Jan 2004 04:17:41 GMT

Hi,

The max lenght of the hostname should be 8 characters.

Robert-Jan

Re: hostname length

Michael Tully — Tue, 13 Jan 2004 04:22:22 GMT

8 characters is the standard maximum length. You will find problems attempting to make it longer.

Re: hostname length

Stefan Farrelly — Tue, 13 Jan 2004 04:25:16 GMT

The limit is 64 characters, although you can use a hostname up to 255 characters anything greater >64 characters may cause problems so its advisable to stick to <=64.

Check out this detailed question and answers;

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=301546

Re: hostname length

Ravi_8 — Tue, 13 Jan 2004 04:31:06 GMT

Hi,

8 characters is the maxumum standard length, you can also set the name longer the 8 characters, but it gives problem while executing problems like, swlist etc.

In such case set the hostname from command line

#hostname

Re: hostname length

Fabio Ettore — Tue, 13 Jan 2004 04:31:27 GMT

Ciao Mauro,

you could have problems with long hostname; they are about resolution names, using uname or something else. Just another example: I know a lot of cases about problem of systems with long hostname working on Omniback (now Data Protector).

From the hostname(1) man page:

The name_of_host argument is restricted to
MAXHOSTNAMELEN characters as defined in .

Running grep MAXHOSTNAMELEN /usr/include/sys/param.h shows:

#define MAXHOSTNAMELEN 64 /* max length of hostname */

So, the hostname can be 64 characters but the uname nodename can only be 8.

I hope this helps you.

Best regards,
Ettore

Re: hostname length

Jakes Louw — Wed, 14 Jan 2004 02:34:12 GMT

Ettore is on the button: while you can set hostname to more than 8 chars, other routines have a fit or just truncate this down to 8 anyway.

This would be, among others, DNS, NIS/YP, and so on.
Some of the sub-routines like gethostent and so on do not check the name length, but assume 8 chars, I suppose.

Funny how UNIX works, eh?

Re: hostname length

Jdamian — Wed, 14 Jan 2004 09:52:20 GMT

Did anybody in HP Labs think to plant the increasing of nodename length ?

The nodename is set for UUCP connections but... who uses UUCP connections today ?
Have you ever used a similar command to this:

uucp myfile.txt sys2!sys3!sys4!/home/joe

?

Re: hostname length

Rory R Hammond — Wed, 14 Jan 2004 19:59:23 GMT

I use uucp.

1. Unlike ftp UUCP does handle failed transfers and retries.
2. UUCP notifies the sysadmin when transfers fails

3. UUCP works for dailup and tcp transfers

4. You can restrict commands and directory locations for transfers. (Permissions)

5. UUCP provideds sane notification of arriving data files.
6. You can use scripting with UUCP

Rory

Re: hostname length

Bill Hassell — Thu, 15 Jan 2004 00:01:35 GMT

HP-UX is a standards-based system and uname must remain consistent with the standards. uname is defined as an 8-character (max) name as stated in the man page for hostname. Once a standard is changed, all sorts of problems with compatibility start showing up (can you say Windows?). Each man page documents the applicable standard(s) at the bottom.

Now hostname is limited to 64 characters but nodename (the value reported by uname) is limited to 8 characters. BOTH can be set by editing the /etc/rc.conig.d/netconf file and entering separate values for HOSTNAME and NODENAME.