Hi ,
Explaination in Document Id : S3100005739
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.
Programs that use icmp protocol, such as ping, use a type of
socket called SOCK_RAW. The nature of using raw IP sockets is
that ALL packets received that match the protocol type of the raw
socket are delivered to ALL the sockets using that protocol. It is
up to the application to read all the data in it's socket buffer
and discard the data it's not interested in. If any of these
sockets are full, the icmp source quench message will be generated.
One process that uses one of these sockets is part of DCE, and it
is 'rpcd'. This program opens a raw socket in order to listen for
icmp messages, which it uses to monitor the health of other systems
on the network running DCE. In this case 'rpcd' used a 32K buffer,
and processed the messages received every 5 minutes, which led to
the buffer full condition.
PHSS_17810 addresses the problem by increasing
the buffer size to 128K and processing the messages every 2 minutes.
-USA..
Good Luck..
