Impact of network tuning on cluster

[R.KrishnaKumar]

Hi all,
I am in need to do some network tuning of the following
tcp_syn_rcvd_max 400
tcp_conn_req_max 400
tcp_text_in_resets 0
ip_forwarding= 0
ip_forward_src_routed= 0
ip_forward_directed_broadcasts= 0
ip_respond_to_echo_broadcast= 0
ip_send_redirects= 0
ip_respond_to_address_mask_broadcast=0

I need do know whether these parameters affect the system performance and the clusters.(Give with docs or examples)

Points will be alloted to the answers,

regds..
Krishna

[Alessandro Pilati]

Krishna,
take a look at this:

tcp_syn_rcvd_max :
Controls the SYN attack defense of TCP. The value specifies
the maximum number of suspect connections that will be allowed
to persist in SYN_RCVD state. For SYN attack defense to work,
this number must be large enough so that a legitimate connection
will not age out of the list before an ACK is received from the
remote host. This number is a function of the speed at which
bogus SYNs are being received and the maximum round trip time
for a valid remote host. This is very difficult to estimate
dynamically, but the default value of 500 has proven to be highly
effective.

tcp_text_in_resets:
This value controls whether or not TCP includes explanatory text in
RST segments it sends. RST segments are sent when there are protocol
violations, and the text included when the value of tcp_text_in_resets
is set to one (1 - the default) can be used to determine just what
sort of protocol violation took place. Newer versions of the tcpdump
utility from www.tcpdump.org can be told to display this text.

About the only time one would want to set this to a value of zero is
if he thought that such text would provide useful information to
someone trying to break into the system. This is probably not likely,
but some folks prefer to operate that way.

For the other check at the following documents:

http://www.docs.hp.com/en/TKP-90202/index.html

and at the pdf in attachment.

Hope it can help,
Rgds,
Alex

[Alessandro Pilati]

Krishna,
take also this other attachment ( very good ):

Rgds,
Alex

[Steven E. Protter]

I think in light of the documentation, you need to run some tests.

I would not change all of these parameters at once in a production cluster. I'd want to run some tests in a non-production cluster and see how they turn out.

If that is not an option, then try the changes one at a time.

SEP

[R.KrishnaKumar]

Hi Guys,

Thanks For ur Replies, The real thing is that i wanted to know whether it has any Impacts on the Clustered environment.

And can i set the above said values for these parameters.

If u find any other Docs, pls mail me,


regards,
KrishnaKumar

[R.KrishnaKumar]

The query is resolved. thanks for ur replies.