Linux Gateway

How To Find Linux Gateway Address

This is NOT my work. I’ve just added it to my blog. The original post and author can be found here.

Find out Gateway / router IP address under Linux / UNIX using route command

You need to use route command. This command can manipulates the kernel’s IP routing tables. It can be also use to print gateway / router IP address. Type the following command to see default gateway:
$ route -n
Output:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 ra0
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 ra0

192.168.1.1 is gateway IP address for our computer. The flag U indicates that route is up andG indicates that it is gateway. You can print gateway name, enter:
$ route
Output:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     0      0        0 ra0
default         wrt             0.0.0.0         UG    0      0        0 ra0

Second column prints Gateway hostname / IP address. In our example wrt is gateway.

netstat command example to find out gateway/router IP

Open a terminal and type the following command:
# netstat -r -n
Sample outputs:

Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         192.168.1.254   0.0.0.0         UG        0 0          0 eth1
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth1
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