for school we have to do a linux routing vm between 4 subnet but the routing only works in one way. Let me explain, here is a schematic:
The router in the center is a CentOS 7 fully up-to-date with 4 nic, each one in a different subnet:
10.1.21.151/24 (top) -> lan of client pc and esxi server.
220.127.116.11/24 (left) -> lan of a first windowsServer2016 AD/Exchange
18.104.22.168/24 (bottom) -> lan of a nagios server
22.214.171.124/24 (right) -> lan of a second windowsServer2016 AD/Exchange
The default gateway is 10.1.21.254/24
After enabling ip forwarding in centOS, I can access the nagios web interface from my client so the routing in that way is ok.
But with the nagios server, when i try to quit his subnet and ping my client, esxi, windowsServer1 or 2 -> nothing
Since the router has access to all subnet directly, i did not create any static route. Am i wrong ?
I think it isn't a routing problem but a "software" problem... Firewalld and NetworkManager are disabled.
ip route list ->
default via 10.1.21.254 dev ens13 proto static metric 100
10.1.21.0/24 dev ens13 proto kernel scope link src 10.1.21.151
126.96.36.199/24 dev ens14 proto kernel scope link src 188.8.131.52
184.108.40.206/24 dev ens15 proto kernel scope link src 220.127.116.11
18.104.22.168/24 dev ens16 proto kernel scope link src 22.214.171.124