You symptoms indicate that your DNS server isn't working. Although since you other comptuers are working, this doesn't really fit either.
You can use
harddrive > applications > utilities > network utility
to diagnose the situation.
You can ping <b>google.com</b>. Result:
Ping has started ...
PING google.com (64.233.167.99): 56 data bytes
64 bytes from 64.233.167.99: icmp_seq=0 ttl=244 time=215.362 ms
64 bytes from 64.233.167.99: icmp_seq=1 ttl=244 time=279.597 ms
64 bytes from 64.233.167.99: icmp_seq=2 ttl=244 time=189.747 ms
64 bytes from 64.233.167.99: icmp_seq=3 ttl=244 time=250.657 ms
64 bytes from 64.233.167.99: icmp_seq=4 ttl=244 time=183.232 ms
64 bytes from 64.233.167.99: icmp_seq=5 ttl=244 time=243.753 ms
64 bytes from 64.233.167.99: icmp_seq=6 ttl=244 time=173.108 ms
64 bytes from 64.233.167.99: icmp_seq=7 ttl=244 time=230.239 ms
64 bytes from 64.233.167.99: icmp_seq=8 ttl=244 time=180.639 ms
64 bytes from 64.233.167.99: icmp_seq=9 ttl=244 time=232.177 ms
--- google.com ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max/stddev = 173.108/217.851/279.597/33.615 ms
If that does work, try pinging <b>64.233.167.99</b> Result:
Ping has started ...
PING 64.233.167.99 (64.233.167.99): 56 data bytes
64 bytes from 64.233.167.99: icmp_seq=0 ttl=244 time=189.655 ms
64 bytes from 64.233.167.99: icmp_seq=1 ttl=244 time=213.471 ms
64 bytes from 64.233.167.99: icmp_seq=2 ttl=244 time=257.873 ms
64 bytes from 64.233.167.99: icmp_seq=3 ttl=244 time=172.745 ms
64 bytes from 64.233.167.99: icmp_seq=4 ttl=244 time=226.723 ms
64 bytes from 64.233.167.99: icmp_seq=5 ttl=244 time=171.883 ms
64 bytes from 64.233.167.99: icmp_seq=6 ttl=244 time=260.308 ms
64 bytes from 64.233.167.99: icmp_seq=7 ttl=244 time=172.963 ms
64 bytes from 64.233.167.99: icmp_seq=8 ttl=244 time=198.840 ms
64 bytes from 64.233.167.99: icmp_seq=9 ttl=244 time=181.215 ms
--- 64.233.167.99 ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max/stddev = 171.883/204.568/260.308/32.247 ms
If pinging 17.254.3.183 works but pinging Google.com doesn't. You have a bad DNS Server address.
BDAqua suggests in a post.
You can use OpenDNS for looking up web addresses.
Put these numbers in Network>TCP/IP>DNS Servers for a try...
208.67.222.222
208.67.220.220
I think they now pretend you need to join to use, but you don't.
https://www.opendns.com/homenetwork/start/device/apple-osx-tiger
(Please note that you do not need to a joint Open DNS to use it.)
http://discussions.apple.com/message.jspa?messageID=5908432#5908432
Google provides free dns lookup too. There numbers are:
8.8.8.8
8.8.4.4
Robert