[PLUG] Router configuration: connecting laptop

[Rich Shepard]

To configure a new Ubiquiti EdgeRouter-X (the semi-bricked one will be
restored after this one's up and running) I use a Dell Latitude 2100 laptop.
The laptop's eth0 interface is configured 192.168.1.55, netmask
255.255.255.0, broadcast 192.168.1.255. The router has the generic default
address of 192.168.1.1.

The Dell's eth0 is UP and RUNNING but cannot ping the router; 'network is
unreachable.' There's no gateway for the two hosts, but the default on the
laptop is on a different subnet, that of the LAN (192.168.55.4).

The kernel's routing table shows no route for eth0. When I run:

route add -net 192.168.1.55 Nm 255.255.255.0 eth0

('dev' is optional) the response is a presentation of how the route command
should be run. The syntax looks correct to me. On a few occasions in the
past a host on the LAN subnet has lost its default route which I easily
restored using 'route add default ...' (but eth0 is always shown) so I'm in
new territory here.

While the location of specific files could be distribution-specific, the
commands are the same.

For this 2-host network what do I read to get a route for eth0 so I can ping
the router and communicate with it via its web interface?

TIA,

Rich