Port 81 - what is it and who uses it?

26 Jan 2001

      Hi.

Simple question:

I wonder what port 81 is for and what service on my DMZ is trying to connect to it.

I looked into several firewall books but the problem is they don't have a port number
index.

Of course I can read from /etc/services:

hosts2-ns        81/tcp                 # HOSTS2 Name Server
hosts2-ns        81/udp                 # HOSTS2 Name Server        

So what is HOSTS2 and to avoid future simple questions like this one,
where can I look for a reference?

thanks in advance,

	Rainer

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