When the customer have all cables connected to RTN, everything works OK
When the customer test the vrrp backup (disconnecting one of the cables) and wants to access the web interface remotely, its not possible. They ping the IP address, and it fails.
The client is connected on another vlan segment, the gateway is correctly configured, so it must ping.
With both cables connected, we test through ping to each device on the local side and remote side.
Ping is OK
We remove one cable to test the vrrp, and the ping to the remote RTN is lost, but all other devices are OK.
So we have checked the network segments, and we have found that the client was on the same network segment as the RTN, so when the interface is down, the RTN keep sending the packets through this interface,
According to the attached topology, the local RTN sends the packet through the interface NMS/COM, and when this is disconnected, the packets are back through this same interface, which causes to fail because this interface is down,.
We have advised the customer to change the RTN NMS/COM IP address, after this, the service is normal.