Time to live exceeded, result after pinging the gateway from host in one subnet

Solution 1:

If you run a traceroute, you'll probably see it bounce between two hops. This often happens when a route is missing.

Solution 2:

The most probable cause is: the gateway is down.

Check if the gateway (router) is up, check the IP (if it's set correctly), check if you can ping the computers from that gateway, and if there is no firewall rule blocking pings/traffic to the gateway.

Solution 3:

Could be that you made a loop with routing? TTL is reduced by 1 at every hop, and will cancel the packet if it reaches 0. To prevent circling packets all over the internet.

Anyway give routing tables a tough check again. Might be there is a small bug inside...