Cannot ping outside university

[David]

Thanks for the many fast responses.

/etc/resolv.conf showed that the DNS servers on the PC were correct
nameserver 194.57.91.200
nameserver 194.57.91.201

But on the laptop despite trying many times with the networking GUI to set the
DNS servers to those values something kept automatically changing them to 

nameserver 10.0.1.1

I have no idea why these automated edits were going on or how I might
stop them, but I edited /etc/resolv.conf manually to match that of the
PC.

Then there was a difference in the /etc/network/interf files. For the PC this file looked like 

dave at PC:~$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 193.55.70.186
        netmask 255.255.255.0
        network 193.55.70.0
        broadcast 193.55.70.255
        gateway 193.55.70.254
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 194.57.91.200 194.57.91.201

The "network 193.55.70.0" line was missing from the file for the laptop. So I added that line and what do you know

dave at Dell-Laptop:~$ ping -c 3 google.com
PING google.com (64.233.187.99) 56(84) bytes of data.
64 bytes from 64.233.187.99: icmp_seq=1 ttl=239 time=111 ms
64 bytes from 64.233.187.99: icmp_seq=2 ttl=239 time=110 ms
64 bytes from 64.233.187.99: icmp_seq=3 ttl=239 time=110 ms

--- google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 110.579/111.001/111.436/0.520 ms

Bingo!!!!!

Thanks for every one who has contributed to saving our skins! This is
my first posting to the Ubuntu forums and I gotta say...

... you guys rock!!!!

cheers and beers
Dave 87)




> 
> You might want to look in to DNS as a culprit? What are the DNS servers
> used on the PC? What are they on your laptop? Usually
> under /etc/resolv.conf   and perhaps listed in /etc/network/interfaces
> Also universities may use some kind of proxy system, is yours setup OK
> to cope with it? Is it possible the university changed it's system in
> someway recently?
> 
>