Pauline Middelink <[EMAIL PROTECTED]> writes:
>
> Now for the strange part; after some 50 minutes orso, the TV
> program ended, I pressed a button on the notebook, and presto...
> The mailreader responded immediately...
>
> HOW???? The notebook was suspended, how could the TCP stack
> on the mailmachine possible received acks? Or is the TCP/IP
> timeout that long?????
The only packets on an idle TCP connection that would need to be ACKed
are TCP keep-alives. According to RFC1122 "Requirements for Internet
Hosts" the minimum idle time before sending a keep-alive must be two
hours. (Moreover, keep-alives must by default be disabled on every
newly created socket. However, "ssh" and "sshd" can be configured to
turn keep-alives on with the "KeepAlive" configuration parameter---in
a default installation, I believe they are turned on in both cases.)
Though Linux 2.0.xxx gets it wrong and sets the default keep-alive
time (/proc/sys/net/ipv4/tcp_keepalive_time) to 15 minutes, Linux
2.1.xxx sets the default keep-alive time to a whooping 3 hours, so
that's why your 50 minutes of idle time didn't disconnect you.
Kevin <[EMAIL PROTECTED]>
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