I changed the DHCP configuration on my current DHCP server. It now points toward the DNS server on this server. After a ipconfig /renew on my XP the DNS was pointing to the new DNS server. Unfortunatelly the ping did not work. In the log file I found that the firewall was blocking it. I added a rule to the firewall to enable port 53 and now it worked.
iptables -A ${LAN}_FW -p udp --dport 53 -j ACCEPT
After this small victory I decided to put Squid into action (I installed it yesterday). I changed (through DHCP) the gateway to the router. Again the firewall blocked the requests to port 3128. I added the rule to the firewall and now Squid took care of the requests. But that was all. There is something wrong with the configuration of Squid. I get a web page with:
The following error was encountered:
* Invalid URL
Some aspect of the requested URL is incorrect. Possible problems:
* Missing or incorrect access protocol (should be `http://'' or similar)
* Missing hostname
* Illegal double-escape in the URL-Path
* Illegal character in hostname; underscores are not allowed
Now I have to find where the problem lies.