topic Re: IP packet size in Operating System - HP-UX

IP packet size

Animesh Chakraborty — Fri, 31 Aug 2001 01:06:36 GMT

Hi All,
How can I change the default IP packets size in hp-ux ?
In AIX it is tcp_mssdflt=512 and also is there any equivelent parameter in hp-ux to set send/receive buffer size?
In AIX it is
tcp_sendspace=16384
tcp_recvsize=16384

Thanks in Advance
Animesh

Re: IP packet size

Varghese Mathew — Fri, 31 Aug 2001 01:32:30 GMT

Hi Animesh ,

Should be like this..

Use recive socket buffer size and send socket buffer size options along with rcp command to get better performance

ex.
rcp -R -S

where "-R" is for receive buffer sixe and "-S" is for sending buffer size.

Hope this helps

Cheers !!!
Mathew

Re: IP packet size

Sridhar Bhaskarla — Fri, 31 Aug 2001 06:00:52 GMT

I don't think there is anyway we can change these settings on HP-UX. I am interested to know what command (not calls) you use in AIX to alter this behaviour globally?

In HP-UX, following are the equivalents for your AIX parameters.

tcp_mssdflt -> TCP-MSS = 536
IP-MSS= 576

For socket buffer send and receive sizes,

SO_SNDBUF = 4097
SO_RCVBUF = 4098

-Sri

Re: IP packet size

Animesh Chakraborty — Fri, 31 Aug 2001 06:40:55 GMT

Hi Sridhar,
Frankly speaking I work only with hp-ux.
I will check with my AIX colleguae how do they change these paramater.
The equivalent parameter you mentaioned in hp-ux,how to find them out ?? I think they are not tunable kernel parameter.

Thanks
Animesh

Re: IP packet size

Animesh Chakraborty — Fri, 31 Aug 2001 07:03:07 GMT

Hi sridhar,

In AIX they use the network options command

no -o tcp_mssdflt=XXXX i.e.

Anything in hp-ux?
Thanks
Animesh

Re: IP packet size

Sridhar Bhaskarla — Fri, 31 Aug 2001 10:25:00 GMT

Animesh,

In HP, we use ndd command to tune most of the network related parameters. I don't remember seeing any of such parameters that are related to your send and receive buffer sizes.

I don't know if there are other unsupported parameters by HP with ndd command.

-Sri

Re: IP packet size

mostefai mourad — Sat, 01 Sep 2001 16:18:19 GMT

hello,

I think you should try this:set up a route (just for testing between both hosts) with an MTU size of 512 (route -p 512 add host

if both servers are
in the same subnet :

Example :
# route -p 512 add host 192.6.2.10 192.6.2.2

Mourad.

Re: IP packet size

harry d brown jr — Sat, 01 Sep 2001 20:04:57 GMT

I think you need to take a close look at "lanadmin" to make your network changes.