Trunk configuration in ASA tranparent mode

[MrBeginner]

Hi,

I would like ask about tranparent mode ASA.

i want to integrate my network with customer network.

myl2 switch===>ASAtranparent===>customer switch.

Now problem is customer switch configure trunk port which connected to our firewall.

my side is create only one vlan on the switch .Firewall didn't create vlan.

So i would like to now can i create the trunk allow vlan in outside interface?

if i don't want to create the trunk link in outside interface what should we do?

let me know which way is the better?

[Aref Alsouqi · Accepted solution]

I would say if there is no requirement to trunk the connection, it would be better to ask you customer to remove the trunk and set up the connected port to the outside interface in access mode.

If that is not an option, then you can do something like this on the firewall outside interface to work on the trunk link:

interface Gi0/0
 no nameif
 no security-level

interface Gi0/0.xxx
 vlan xxx
 nameif outside
 bridge-group 1
 security-level 0

interface Gi0/1
 nameif inside
 bridge-group 1
 security-level 100

interface BVI1
 ip address xxx.xxx.xxx.xxx 255.255.255.0

That should work. If you don't want to use trunk, just configure the outside interface similar to Gi0/1 changing the nameif and the security level.

[MrBeginner]

Hi @Aref Alsouqi ,

let me know if i configure my switch port which connected to ASA inside interface and customer switch port which connected to asa outside interface are access port and same vlan ,it should work ?

Or can we allow all vlan on trunk link ?

[Aref Alsouqi]

Yes, you can configure both switches ports connected to both interfaces of the ASA in the same VLAN, that should work.