Using Dual ISP's with ASA5505

[razorbakill]

for the purpose of a redundency, incase the primary ISP goes down the backup kicks in.

Can this be done with the basic license (max 3 vlans) or you need to have the security plus license. (20 vlans)

Currently not using the 3rd vlan (dmz)

[Jia Liu · Accepted solution]

You would need the security plus license.

[Kureli Sankar · Accepted solution]

With the base license you do get  3 zone (2 regular zones and 1 restricted zone). But with the restricted zone you can only talk to one vlan either inside or outside.  For redundancy to work when one ISP goes down you would want the 3-rd zone to talk to the inside and outside.

http://www.cisco.com/en/US/docs/security/asa/asa82/configuration/guide/license.html#wp1330679

With the Base license, the third VLAN must be configured with the no forward interface command to restrict this VLAN from initiating contact to one other VLAN.

http://www.cisco.com/en/US/docs/security/asa/asa82/command/reference/ef.html#wp1934395

So, you need security plus license so, you will not have this restriction.

-KS

[razorbakill]

I had a feeling you needed the security plus,

Thanks for confirming

[Nikita Borodavko]

Can you explain me some in this case.

You said "But with the restricted zone you can only talk to one vlan either inside or outside"

Does this mean that restricted zone can only talk with one other zone?

For example, why we can't do so with ASA base license:

create VLAN 1 for INSIDE

create VLAN 2 for main ISP

create VLAN 3 ( restricted, this VLAN can communicate only with one other, right?) for backup ISP and it will communicate only with VLAN 1 INSIDE.

VLAN 3 (backup ISP) should not communicate with main ISP vlan.

What's wrong with my thinking?

Thanks in advance for your reply

[John Peterson]

It makes sence that you don't need a set plus license to have ISP failover as your outside traffic would never forward traffic to the failover ISP.