I am using the GNS3 simulator, and I need to connect two Cisco C7200 routers.
When I enter the ip address 126.0.0.4 255.255.255.252
command, I get Bad mask /30 for address 126.0.0.4
.
I am using the GNS3 simulator, and I need to connect two Cisco C7200 routers.
When I enter the ip address 126.0.0.4 255.255.255.252
command, I get Bad mask /30 for address 126.0.0.4
.
That is because 126.0.0.4/30
is the network address, not a host address. See the answer to How do you calculate the prefix, network, subnet, and host numbers? for how to calculate that.
For a /30
network, there are two host addresses: subnet + 1
and subnet + 2
. In your particular example, that would be 126.0.0.5
and 126.0.0.6
.
126.0.0.4/30 is the network address. To work, the IP of the first host should be 126.0.0.5/30(Gateway) and the second host 126.0.0.6/30