irfan and ionannis,
You guys obviously are not following the mail thread or reading the results. This is not a "basic networking issue" that has been highlighted. The fact that the captures show results back from the router indicates that DNS and internet connectivity is working. The problem here is that the client is rejecting the DNS response (hence the ICMP port unreachable message). So we are not looking for a network connectivity problem as much as a operating system level issue as to why a perfectly valid DNS response is being rejected.
Regards, Martin
MartinVisser99@xxxxxxxxx