My client OS is Windows, and local IP is 172.16.2.21. The default gateway is 172.16.2.1, which is a 3-Layer switch. And the NAT router is 172.16.100.254. The client can access Internet.

Now I wanted to test a new router and a new Internet line. The new router IP is 172.16.101.254. But I didn’t want to change 3-Layer switch configuration before I verified the new devices and configs.

So I tried to change routing table in Client OS only. I removed the default routing 0.0.0.0/0.0.0.0, and added two static routing 172.16.0.0/16 via 172.16.2.1, and 0.0.0.0/0 via 172.16.101.254. So the routing table looks like this.

Network     Mask         Gateway         Interface    Metrics
0.0.0.0     0.0.0.0      172.16.101.254  172.16.2.21  6
172.16.0.0  255.255.0.0  172.16.2.1      172.16.2.21  6

I can ping to 172.16.101.254, but cannot ping Internet IPs like 8.8.8.8. The ping command returned network unreachable or timeout. What’s wrong?