ASA: IP address configuration on two interfaces of same subnet.

[suryakant.patil]

In Cisco ASA we can configure IP address from Supersubnet pool on two different VLAN as below.

If you check 10.231.23.145 is IP address of Supersubnet of 10.231.23.128/27.

Can any one know why this is allowed on Cisco ASA and same thing is not allowed in Router?

interface GigabitEthernet0/5.923

vlan 923

nameif Space

security-level 42

ip address 10.231.23.129 255.255.255.224

gs-cust-asa# sh run int gig0/5.934

!

interface GigabitEthernet0/5.934

vlan 934

nameif Test123

security-level 54

ip address 10.231.23.145 255.255.255.240

[Jennifer Halim]

it is incorrect configuration on the ASA.

The ASA does not check whether there is any overlapping ip address on its interfaces. however, this configuration will not work properly and might cause issue on the ASA.

You are absolutely correct where it overlaps and it shouldn't be configured with overlapping subnet on the networking devices, whether it is router or ASA.