A rebuilt Linux router answers pings but forwards nothing
TroubleshootingCore
The ticket
GW1 is an Ubuntu box that routes between the user LAN 10.20.0.0/24 (ens224, 10.20.0.1) and the server LAN
10.30.0.0/24 (ens192, 10.30.0.1). There is no NAT: both LANs route to each other through GW1. Last night it
was rebuilt from the company's new hardened server image and its netplan file was restored from backup.
This morning nobody on the user LAN can reach SRV1 (10.30.0.10). From PC1 (10.20.0.10, a Linux laptop),
ping 10.20.0.1 and ping 10.30.0.1 both work.
Step 1 of 3
PC1 can ping both of GW1's addresses. What does that tell you, and what do you do next?