Oracle DB 11.1.0.7.2 on Linux x86-64 (RHEL 5.3). The tnslsnr process is bound to port 6150 on localhost with high sendq and recvq values. This is only the case on a production server, and does not appear to be causing any issues for users. However it seems quite strange.
[oracle@hostname ~]$ netstat -antp | egrep '(tnslsnr|^(Proto|Active))'
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:1521 0.0.0.0:* LISTEN 2282/tnslsnr
tcp 73904 139136 127.0.0.1:6150 127.0.0.1:6150 ESTABLISHED 2282/tnslsnr
tcp 0 0 [blocked]:1521 [blocked]:11356 ESTABLISHED 2282/tnslsnr
None of my other servers have tnslsnr on any ports other than 1521. Has anybody else seen this behavior before? I can't find anything useful on MOS, the only doc remotely applicable looks like 831153.1 which shows some lsof output with tnslsnr connected to port 6150.
I have an incorrect /etc/hosts entry with the server's short hostname (non-FQDN) assigned to 127.0.0.1 (the FQDN is assigned to the proper IP). Could something that simple cause this? I'll fix that at my next maintenance window, but I wouldn't expect that to cause the listener to do something on port 6150 without any other reason.