topic Re: Quench Reply in Operating System - HP-UX

Quench Reply

Carme Torca — Tue, 01 Jul 2003 08:48:56 GMT

Hi,

I have two servers (S16K-A and N4000-75) with HP-UX v.11.11. When I do a ping outside these servers, it returns: QUENCH REPLY.

The people of routers have seen a lot of things, but they doesn't find anything... is anyone knows if it could be from the server.... maybe because the server is work a lot of???. Any idea?

Thanks a lot of,
Carmen.

Re: Quench Reply

T G Manikandan — Tue, 01 Jul 2003 09:01:53 GMT

/*
ICMP source quench messages are generated when an IP packet is
received by the 11.0 system that can't be delivered to the socket
buffer of the receiving application. The intent is to inform the
sender of the full buffer condition so the rate of the transmission
is slowed down until the buffer can be read by the receiving
application.

Setting the ndd parameter ip_send_source_quench to 0 can be an
effective way to deal with the messages.

Just do a
#ndd -get /dev/ip ip_send_source_quench

If it returns a 1 source quench turned on
turn it off using

#ndd -set /dev/ip ip_send_source_quench 0

to persist the change after reboot make entries in
/etc/rc.config.d/nddconf file

Re: Quench Reply

Enrico P. — Tue, 01 Jul 2003 09:08:55 GMT

Hi,
add this entry in the nddconf file for set quench to 0:

TRANSPORT_NAME[0]=ip
NDD_NAME[0]=ip_send_source_quench
NDD_VALUE[0]=0

and

ndd -c

for Read input from the configuration file
/etc/rc.config.d/nddconf and set the tunable parameters.

Enrico.

Re: Quench Reply

Steven Sim Kok Leong — Tue, 01 Jul 2003 11:00:43 GMT

Hi,

If you are performing a ping from the HP-UX servers and received a source quench from the pinged system, then it is the pinged system that has to disable ICMP source quench.

The source quench is a way for the pinged system to tell the pinging system that it is sending ICMP traffic too fast for it to handle i.e. giving a "please slow down" signal.

Hope this helps. Regards.

Steven Sim Kok Leong

Re: Quench Reply

Bill Douglass — Tue, 01 Jul 2003 11:07:39 GMT

Source Quench is sent back from a host when it cannot deliver packets to the destination socket quickly enough. There is a bug in HP-UX 11.0 that causes it to return excessive SQ messages as well.

Are you pinging an HP-UX 11.0 box from your 11i servers? If so, there is a patch to fix this problem in 11.0 (PHSS_27962 ).

If you are seeing this when pinging any host, then something else is afoot.