Re: tcp_keepalive_intvl vs tcp_keepalive_time?

From: Nivedita Singhvi (nivedita@us.ibm.com)
Date: Sat Feb 09 2002 - 23:40:15 EST


> Would someone be kind enough to explain the difference between
> tcp_keepalive_intvl and tcp_keepalive_time?
> Documentation/filesystems/proc.txt says tcp_keepalive_time is the
interval
> between sending keepalive probes, but doesn't mention
tcp_keepalive_intvl...

tcp starts a keepalive timer for each connection. if the connection is idle
for tcp_keepalive_time seconds, it starts sending probes to the other end.
It sends a maximum of tcp_keepalive_probes each tcp_keepalive_intvl
seconds apart, and if the other end hasnt responded by then, it drops the
connection.

default values:

tcp_keepalive_intvl = 75 seconds
tcp_keepalive_probes = 9
tcp_keepalive_time = 7200 seconds (2 hours)

> The problem I'm trying to track down is ssh connections where the
connection
> times out but the session doesn't go away until a key is pressed. (I.E.
> blocking reads don't notice the connection going down underneath them,
not
> even if left overnight.)

not clear from the info here whats happening in your case...
(stats?)

> Rob

thanks,
Nivedita

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This archive was generated by hypermail 2b29 : Fri Feb 15 2002 - 21:00:30 EST