Re: Laptop Connects to WAP, But Cannot Access 'Net

On 26/03/2012 23:39, Rich Shepard wrote:
> On Mon, 26 Mar 2012, Bengt Richter wrote:
>
>> Hm, maybe a DNS problem? Can you put in fixed DNS numbers for your ISP's
>> DNS servers to see if there's a problem with automatic DNS, if that's 
>> what
>> you have going?
>
> Bengt,
>
>   It appears like a DNS issue. At yesterday's site when wicd 
> established a
> connection their DNS server filled /etc/resolv.conf with their search 
> domain
> name and their two DNS server IP addresses.

Start with an ifconfig -a to see what IP addresses are assigned to the 
offending machines. It could be that they lack an IP address from DHCP.

If they have a valid IP address, run route -n to give you your routing 
table.

Once you have the gateway IP address, attempt to ping that IP address.

Attempt to ping google by its IP address by looking up the IP address on 
a machine you know works, writing it down on a piece of paper and then 
typing it in.

Run a traceroute -n on google's IP address.

If you have a valid IP address, can ping your gateway IP and traceroute 
to google's servers without resolving DNS, you know its a DNS problem. 
If it fails on any one of these steps, you know where the problem lies.

If you know the router's address on a working machine, you could try 
setting a static IP address if DHCP has failed to find a suitable 
address, preferably a high number. If the router IP address is 
192.168.0.254 or 192.168.0.1, and you know working machines have been 
allocated 192.168.0.6 upwards, try allocating a static IP address of 
192.168.0.100

Best,

John