tcp_keepalive_interval

[Ed Hon]

What is the purpose of the tcp_keepalive_interval? Is the default of 2 hours "too long".

[Cheryl Griffin]

The parameter tcp_keepalive_interval determines the amount of time that TCP
waits for an idle connection with no unacknowledged data before sending
keepalive packets. The default is 2 hours.

[Alex Glennie]

The parameter tcp_keepalive_interval determines the amount of time that TCP
waits for an idle connection with no unacknowledged data before sending
keepalive packets. The default is 2 hours.

[John Palmer · Accepted solution]

Ed,

If you are on 11.00 do:-

ndd -h tcp_keepalive_interval

The default of 2 hours may be too long depending on your circumstances. Do you have lots of network connections that get lost (clients crashing and the like)?

If you reduce the interval then you may cause a slight increase in network traffic.

[Stefan Farrelly]

Yes, 2 hours is too long to keep alive idle TCP connections. Weve set ours down to a much more reasonable 15 minutes, but you should only do so if your suffering from lots of open TCP sockets waiting to finish - ie. do a netstat -a|grep tcp|grep FIN

[Cheryl Griffin]

Ed,

The two hour time limit should be fine. The connected machines, will stay connected and you won't know the difference. Then after the two hours, your machine will start polling the other to see if it is still there. Say the other machine crashes, no ACK will be sent back and the systems will disconnect. Otherwise it will just keep polling and wait for the response.

[CHRIS ANORUO]

Check these links for previous threads http://my1.itrc.hp.com/cm/QuestionAnswer/1,1150,0x8b4b49c5ae73d4118fef0090279cd0f9,00.html

http://my1.itrc.hp.com/cm/QuestionAnswer/1,1150,0x28a683667c40d4118feb0090279cd0f9,00.html