2006-Apr-03

On a Linux system, netstat was outputting

warning, got duplicate tcp line

This is apparently a harmless situation where there are identical recorded TCP connections, because of rapid connections re-connecting on the same address/port tuple.

I read that this can be turned off with the net.ipv4.tcp_tw_recycle and net.ipv4.tcp_tw_reuse sysctl's.

(I also read the netstat output may be "warning, got BOGUS tcp line".)