topic Re: Permanent MTU size changes. in Operating System - HP-UX

Permanent MTU size changes.

Marc Dijkstra — Fri, 07 Dec 2001 12:07:36 GMT

Hey there gurus

I have an L-Class running UX 11.0. I need to permanently change the MTU size on lan0. It cannot be done thru SAM, and although the
#lanadmin -M 1400 0 works, it is not permanent.

Where do I change the MTU size to make this permanent? I know one can do this for the lan address in /etc/rc.config.d/hpetherconf, but not MTU.

Also I was told that one can set the cards to MTU "autosense" with ndd, is anyone aware of this tweak?

Cheers
MND

Re: Permanent MTU size changes.

harry d brown jr — Fri, 07 Dec 2001 12:17:11 GMT

You make the change in the appropriate /etc/rc.config.d file that corresponds to your lan driver.

live free or die
harry

Re: Permanent MTU size changes.

Marc Dijkstra — Fri, 07 Dec 2001 12:22:49 GMT

Thanks Harry, but there are only 2 files:
/etc/rc.config.d/hpetherconf and /etc/rc.config.d/hpbase100conf.

They only let you do:
# HP_BASE100_INTERFACE_NAME Name of interface (lan0, lan1...)
# HP_BASE100_STATION_ADDRESS Station address of interface
# configured through lanadmin(1m)
# Prefixed with "0x".
# HP_BASE100_SPEED Manually set the driver's speed. Can be
# one of: 10HD, 10FD, 100HD, 100FD, auto_on

I am not sure if there is a setting in the /etc/rc.config.d/nddconf that can be set?

MND

Re: Permanent MTU size changes.

Steven Gillard_2 — Fri, 07 Dec 2001 12:42:10 GMT

You will probably have to write your own startup script for this one, so that the lanadmin -M command is run on every system boot. Start with a copy of /sbin/init.d/template as a guide and put your appropriate lanadmin commands under the 'start' section. You can then link it into /sbin/rc2.d somewhere after the hpbase100 script runs.

Regarding your other question, I think the ndd parameter you are referring to is ip_pmtu_strategy, which controls the way HPUX discovers the path MTU for a routing table entry. There are a couple of different ways this parameter can be set - check "ndd -h ip_pmtu_strategy" for details. This is not configurable on a card by card basis, however.

Regards,
Steve

Re: Permanent MTU size changes.

Eugen Cocalea — Fri, 07 Dec 2001 12:52:49 GMT

Hi,

Modify the /etc/rc2.d/S320hpether or /etc/rc2.d/S323hpbase100 files directly. Or you can make it more elegant, modifying the conf files and then read the configs from them. You can always define new variables in either the config files or scripts and the command line according to the new parameters...

E.