topic Re: LINUX Red Hat AS 4.0 Hostname Character Limitation in Operating System - Linux

LINUX Red Hat AS 4.0 Hostname Character Limitation

Cliff Lim Kok Hwee — Wed, 18 Jan 2006 03:04:16 GMT

Hi Forum,

For HP-UX hostname is limited to 8 characters.

Query: How about for RedHat Linux AS4.0 server hostname? Any character limitation?

Thanks/cliff

Re: LINUX Red Hat AS 4.0 Hostname Character Limitation

Stuart Browne — Wed, 18 Jan 2006 03:26:12 GMT

The length of the fully-qualified hostname should be less than 255 characters.

But in reality, if 8-10 characters isn't enough, what the hell are you naming that poor thing?

:)

As for restrictions on the characters to use, try to keep it to alpha-numeric with _'s and -'s if you have to.

Re: LINUX Red Hat AS 4.0 Hostname Character Limitation

Cliff Lim Kok Hwee — Wed, 18 Jan 2006 03:30:32 GMT

HAHAHA. Thanks for the input Stuart.

Then should be fine.

Application folks like to keep it LONG. eg identify their application name + whether prod or dev etc.

Thanks/cliff

Re: LINUX Red Hat AS 4.0 Hostname Character Limitation

Ivan Ferreira — Wed, 18 Jan 2006 06:43:41 GMT

From RFC 952

A "name" (Net, Host, Gateway, or Domain name) is a text string up
to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
sign (-), and period (.). Note that periods are only allowed when
they serve to delimit components of "domain style names".

No blank or space characters are permitted as part of a
name. No distinction is made between upper and lower case. The first
character must be an alpha character [Relaxed in RFC 1123] . The last
character must not be a minus sign or period.

From RFC 1035

labels 63 octets or less
names 255 octets or less

[snip] limit the label to 63 octets or less.

To simplify implementations, the total length of a domain name (i.e.,
label octets and label length octets) is restricted to 255 octets or
less.

From RFC 1123

One aspect of host name syntax is hereby changed: the
restriction on the first character is relaxed to allow either a
letter or a digit. Host software MUST support this more liberal
syntax.

Host software MUST handle host names of up to 63 characters and
SHOULD handle host names of up to 255 characters.

Re: LINUX Red Hat AS 4.0 Hostname Character Limitation

dirk dierickx — Thu, 19 Jan 2006 03:11:10 GMT

yeah, that 8char limit on hpux has to go...

Re: LINUX Red Hat AS 4.0 Hostname Character Limitation

Steven E. Protter — Thu, 19 Jan 2006 03:18:32 GMT

Shalom cliff,

Note: HP-UX 11i v2 does have an add in software from software.hp.com to override the 8 character limit.

AS 4.0 does not have this limit and provides for more meaningful names.

Anyone need a hostname bigger than 15 characters though? Realistically?

SEP