Operating System - HP-UX
1848533 Members
4163 Online
104033 Solutions
New Discussion

Re: Permanent MTU size changes.

 
SOLVED
Go to solution
Marc Dijkstra
Trusted Contributor

Permanent MTU size changes.

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
"A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila"
4 REPLIES 4
harry d brown jr
Honored Contributor

Re: Permanent MTU size changes.

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

live free or die
harry
Live Free or Die
Marc Dijkstra
Trusted Contributor

Re: Permanent MTU size changes.

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
"A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila"
Steven Gillard_2
Honored Contributor
Solution

Re: Permanent MTU size changes.

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
Eugen Cocalea
Respected Contributor

Re: Permanent MTU size changes.

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.
To Live Is To Learn