I have looked these over, and everything seems right.My only guess is that it's a problem with some static gateway assignment on 192.168.21.10. If the source that was pinging is outside the subnet, then it will route replies to the locally assigned gateway. (This is generally assigned through DHCP but can be overridden.)I think you'll might need to use Wireshark or tcpdump on the interface that is being pinged to see the traffic to/from the interface. You can detect which path is failing and trace out the problem, but I would check the gateway on 192.168.21.10 first.
I can't find any details on your hardware, is it virtual or real? Which type of interfaces?
Another question: Have you ever enabled Intrusion Prevention?
LAN (igb0) is shown as disconnected (no carrier). Is this expected / was it unplugged when taking the screenshot?
Just, i want to ask you that, is it anyway to re-configure the routes according to current interfaces and network structure? Is there any terminal code, shell script or any other?