Hi There, I'm sorry if I've mailed this to the wrong mailing list , but I reckon you guys would know best :) Some off my clients started complaining that they're having problems connecting to my mail server. Now all this worked fine up until yesterday. I'm not blocking any ports nor am I blocking ICMP on the network. If I try and ping the mail server from the clients computer I get the following message. [root@ceda root]# ping 217.10.176.138 PING 217.10.176.138 (217.10.176.138) 56(84) bytes of data. >From 10.0.5.1: icmp_seq=2 Redirect Host(New nexthop: 217.10.176.138) >From 10.0.5.1: icmp_seq=3 Redirect Host(New nexthop: 217.10.176.138) And here comes the weird part, the moment I restart the client's network all problems disappear for at least an hour or two. I have about 50 customers on my network and only about half off them is experiencing this problem and it's on both Windows / linux boxes. I only have this problem accessing the mail server, the rest of the servers hosted on the 217.10.176.136/29 network works fine. I can also ping the same clients pc from the mail server without any problems. [root@mail routers]# ping 10.0.5.2 PING 10.0.5.2 (10.0.5.2) 56(84) bytes of data. 64 bytes from 10.0.5.2: icmp_seq=1 ttl=64 time=0.260 ms 64 bytes from 10.0.5.2: icmp_seq=2 ttl=64 time=0.235 ms Here's my network layout. Cisco Router : (217.10.176.149/255.255.255.252) ----------------------------- FIREWALL : eth0 (217.10.176.150/255.255.255.252) : eth1:client1 (10.0.5.1/255.255.255.252) : eth1:client2 (10.0.4.1/255.255.255.252) : eth1:mail (217.10.176.137/255.255.255.248) Routing table for the firewall. 10.0.5.0 0.0.0.0 255.255.255.252 U 0 0 0 eth1 10.0.4.0 0.0.0.0 255.255.255.252 U 0 0 0 eth1 217.10.176.136 0.0.0.0 255.255.255.248 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 217.10.176.149 0.0.0.0 UG 0 0 0 eth0 ----------------------------- MAIL SERVER : eth0 (217.10.176.138/255.255.255.248) Routing table on the Mail Server 217.10.176.136 0.0.0.0 255.255.255.248 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 217.10.176.137 0.0.0.0 UG 0 0 0 eth0 ----------------------------- Client PC 1 : eth0 (10.0.5.2/255.255.255.252) ----------------------------- Client PC 2 : eth0 (10.0.4.2/255.255.255.252) ----------------------------- Some input would be greatly appreciated. Kind Regards Stephan
