Internet Gateway
192.168.0.201
Server 1
192.168.0.101
192.168.1.101
192.168.2.101
gateway: 192.168.0.201
VIP: 192.168.1.100
VIP: 192.168.2.100
Server 2
192.168.0.102
192.168.1.102
192.168.2.102
gateway: 192.168.0.201
Client 1
192.168.2.201
gateway: 192.168.2.100
From Client 1, I can ping 192.168.2.102 (Server 2), this would make sense all three computers are on the same network. However, from client 1, I cannot ping or ssh to 192.168.1.102 (server 2). Why? I don't know. Using wireshark, I can see the ICMP echo request go through server 1 and pass to server 2. This path makes sense. I see the echo request being recieved on the 192.168.2.102 NIC on Server 2. But no response is sent out on either NIC on Server 2. Why?
I have made no routing table modification on either server. I have IP forwarding set in sysctl.conf on both servers. I have iptables turned off. The only way I can ping from client 1 to 192.168.1.102 (server 2) is enabling masquerading in iptables on both servers on all interfaces. The question is: why can't client 1 ping to 192.168.1.102 with no modifications to any routing table and with the iptables service stopped?