In a project we at vBridge are working on, we rely on a Virtual Private Network to link our connected devices, certain servers, and our webapp together. I had an issue where a specific server in the
10.55/24 range was nog being reachable.
While debugging the issue — going deeper into the rabbit hole called the 5 Whys — I eventually needed to verify if the proper routing tables from the VPN connection had been set up or not. To do so, I used
$ netstat -nr Routing tables Internet: Destination Gateway Flags Netif Expire default 192.168.83.1 UGSc en0 default link#19 UCSI utun10 10.77/16 10.77.0.5 UGSc utun10 10.77.0.5 10.77.0.5 UH utun10 127 127.0.0.1 UCS lo0 127.0.0.1 127.0.0.1 UH lo0 169.254 link#5 UCS en0 ! 192.168.83 link#5 UCS en0 ! 192.168.83.1/32 link#5 UCS en0 ! … 255.255.255.255 ff:ff:ff:ff:ff:ff UHLWbI en0 ! 255.255.255.255/32 link#19 UCSI utun10 …
As you can see, the
10.55/24 route indeed wasn’t registered indeed, explaining why the host wasn’t reachable.