Test remote UDP port.

[hcampuzano]

Hello community,

Is there a way to test connectivity from CLI to a public IP address over an UDP port?
I want to verify if UDP/5060 (SIP) is listening on a public IP address of a vendor.
I couldn't find a way to test it from the firewall so far.

I' appreciate if someone could assist me.

Thanks!

[PhoneBoy · Accepted solution]

You can use netcat (expert mode command) to generate a UDP packet.
Something like: netcat -uv 10.6.5.4 5060
Then you'll need to type something and press return.
If you get back a "Refused," then nothing is listening on that port.
Not sure how it will respond if something IS listening on that port.
However, if a firewall is blocking the traffic, you may get no response or possibly an ICMP Port Unreachable message.

[hcampuzano]

This was very helpful, however I don't get any reply. The traffic logs are generated though.