topic Re: change of ip_pmtu_strategy value in Operating System - HP-UX

change of ip_pmtu_strategy value

Alan Buenaventura — Sat, 29 Mar 2003 07:39:47 GMT

Hi,

When changing ip_pmtu_strategy value from 1 to 0, is the change effected immediately?

Thanks.

Re: change of ip_pmtu_strategy value

Ravi_8 — Sat, 29 Mar 2003 07:56:35 GMT

Hi,
yes, it should

Re: change of ip_pmtu_strategy value

Alan Buenaventura — Sat, 29 Mar 2003 08:03:13 GMT

hi,

how come the sniffer trace shows that it is still 1?

here's how i changed it:
ndd -set /dev/ip ip_pmtu_strategy 0

is this correct or have i missed something?

Thanks.

Re: change of ip_pmtu_strategy value

U.SivaKumar_2 — Sat, 29 Mar 2003 08:43:35 GMT

Hi,

After changing PMTU strategy.

#route -f

Then

#/sbin/init.d/net start

Try again the sniffing

regards,

U.SivAKumar

Re: change of ip_pmtu_strategy value

T G Manikandan — Sat, 29 Mar 2003 15:57:54 GMT

You can use
ndd -get /dev/ip ip_pmtu_strategy

to check up the value.

These changes do not persist after reboot so make the appropriate changes in the /etc/rc.config.d/nddconf

Thanks

Re: change of ip_pmtu_strategy value

Alan Buenaventura — Mon, 31 Mar 2003 05:12:32 GMT

That's why the changes can't be seen bec. the sniffing was on the other side.
Switched to the proper sniffing location and saw the changes.
But the changes was not effected immediately, the routes have to be deleted and re-added for the changes to effect.

Re: change of ip_pmtu_strategy value

rick jones — Mon, 31 Mar 2003 18:34:58 GMT

Certainly, once you change ip_pmtu_strategy to zero from one, any _new_ connection will see the change. I'm not sure if it will affect the segment sizes of existing connections right away or not. It may not "take" for them until ip_ire_flush_interval or somesuch.

Of course, one might ask why the change to zero in the first place since it will cripple your TCP connections with a smaller MSS than they could otherwise use.