Port assignment

Linux and Unix-Like Linux
1

Hi all,

I am currently working with SIP protocol.

I have a node that is supposed to accept SIP invite. It should be listening on udp port 35060 but is not.

Every 2.0s: netstat -an| grep 5060                                                                                                                                     Thu Feb 26 13:45:36 2015

tcp        0	  0 192.168.2.106:35060         0.0.0.0:*                   LISTEN
tcp        0	  0 127.0.0.1:35060             0.0.0.0:*                   LISTEN
udp        0	  0 192.168.2.106:35060         0.0.0.0:*
udp        0	  0 127.0.0.1:35060             0.0.0.0:*

Because of this, when I run tcpdump , I get the following;

13:41:10.603075 IP pl-1 > 192.168.2.102: ICMP pl-1 udp port sip unreachable, length 556

How can I start listening on udp port rather than tcp ?

BR

2

UDP is connectionless, it never "listens". That it's there at all is good enough.

I suspect your client is either using a port you didn't expect, or blocked by a firewall. I am trying to figure out how to force tcpdump to print port numbers instead of service names...

What is pl-1 ?