mdsnresponder on port 49159 or 49163

[ryesky]

This is my first post on these forums and I'm a relatively new Mac user. I've always been (excessively and obsessively) paranoid about what runs on my system, more specifically what shows up in netstat and/or lsof. Anyway, I notice there are 5 results for mdnsresponder when I do:

sudo lsof -i

in the terminal... One of them makes me a bit curious:

mDNSRespo 21 _mdnsresponder 12u IPv4 0x2c1d380 0t0 UDP *:49163

I notice it's either this port or port 49159. Like I mentioned, I'm probably going a bit overboard by posting something that's probably trivial, but I always like to know these things, ie: what port 49163/49159 are for with mdnsresponder AND if anybody else has similar results of the "lsof" command. Googling yielded no conclusions.

Thanks.

[wrldwzrd89]

mDNSResponder is a little system service which, I believe, is used to make DNS lookups and other DNS-related things. That is why it can't be disabled from the firewall interface.

[ryesky]

Yea, I figure that much. There are 4 other instances of it in the lsof output (on ports 5353 5351 and 5350 i think), but I can't figure out why it'd be open on such a high port like 49163

[wrldwzrd89]

Yea, I figure that much. There are 4 other instances of it in the lsof output (on ports 5353 5351 and 5350 i think), but I can't figure out why it'd be open on such a high port like 49163
Perhaps because there's an instance of it running for every user currently active on the system. If that's the case, then I suspect that the one on 49163 is yours, and the 535x ones belong to various system-created users.