порт удалённой машины? тогда nmap
$ nmap -P0 mail.ru
Starting Nmap 6.40 ( [url]http://nmap.org[/url] ) at 2014-03-31 14:32 EEST
Stats: 0:00:01 elapsed; 0 hosts completed (1 up), 1 undergoing Connect Scan
Connect Scan Timing: About 1.60% done; ETC: 14:33 (0:01:02 remaining)
Nmap scan report for mail.ru (94.100.180.201)
Host is up (0.023s latency).
Other addresses for mail.ru (not scanned): 217.69.139.199 217.69.139.201 94.100.180.199
rDNS record for 94.100.180.201: ko.mail.ru
Not shown: 983 filtered ports
PORT STATE SERVICE
25/tcp closed smtp
53/tcp closed domain
80/tcp open http
88/tcp closed kerberos-sec
110/tcp closed pop3
143/tcp closed imap
179/tcp open bgp
443/tcp open https
587/tcp closed submission
843/tcp closed unknown
993/tcp closed imaps
995/tcp closed pop3s
1935/tcp closed rtmp
2041/tcp closed interbase
2042/tcp closed isis
2043/tcp closed isis-bcast
2525/tcp closed ms-v-worlds
Nmap done: 1 IP address (1 host up) scanned in 4.34 seconds