Default gateway (III)
Network map
localnet +-------------------------------------+ vmnet +--------------------+
------------|eth0 gateway eth1|---------|eth0 vm |
|192.168.1.44 192.168.56.101| |192.168.56.102 |
+-------------------------------------+ +--------------------+
Default gateway
Probably in the host that has to use the gateway – in our case a virtual machine called vm
– there isn’t configured any default gateway because it is only connected to a network and only needs to comunicate with other hosts in that network.
However if we want to reach hosts in some other networks, we must add a default gateway which in our case will be the server we are configuring right now. So all the outlined steps will happen in the virtual machine vm
.
(root@vm)_$: route add default gw 192.168.56.101 dev eth0
If we want to make this change permanent:
/etc/network/interfaces:
------------------------
auto eth0
iface eth0 inet static
address 192.168.56.102
network 192.168.56.0
netmask 255.255.255.0
gateway 192.168.56.101 <===
Check
From the vm
host we must be able to reach:
- The gateway
(root@vm)_$: ping 192.168.56.101
- Another host in the
vmnet
network
(root@vm)_$: ping 192.168.56.103
- Another host in the
localnet
network
(root@vm)_$: ping 192.168.1.1
-
Another host in the internet
We cannot ping
www.google.com
because we don’t have name resolution, but if we happen to know the IP address for a Google host, we should be able to reach it
(root@vm)_$: ping 173.194.35.147