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: Code: sudo lsof -i in the terminal... One of them makes me a bit curious: Code: 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.