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ASA inter-vlan routing

Hi, I have this situation:

A client of mine has a switched network. On that network where no vlan is configured, he has multiple IP address on the same vlan (vlan 1). So, I´ve installed a 5505 with two vlans, and asigned each vlan to ethernet interfaces. I´ve made 2 connections, from switch to each ASA interface. The problem is when I execute show arp on the ASA, I receive the same entry on both interfaces.

I hope in first place that you understand my english, and in second place you can help me :-)

Best regards!

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

The ARP table will be built

The ARP table will be built based on the ASA seeing ARP broadcasts and replies. If the client has one VLAN (= one broadcast domain) then both interfaces will see all of that traffic and build identical ARP tables.

The correct way to change this would be to create a second VLAN for the second set of IP addresses and assign the appropriate interfaces (including the second ASA client-facing interface) to that VLAN.

1 REPLY
Hall of Fame Super Silver

The ARP table will be built

The ARP table will be built based on the ASA seeing ARP broadcasts and replies. If the client has one VLAN (= one broadcast domain) then both interfaces will see all of that traffic and build identical ARP tables.

The correct way to change this would be to create a second VLAN for the second set of IP addresses and assign the appropriate interfaces (including the second ASA client-facing interface) to that VLAN.

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