routed mode versus transparent mode

[Ben Alex]

I am designing a new data center and will

be using an FWSM at the service layer.

Should  I consider using transparent mode over routed or vice versa?

Which mode offers me the best?

Thanks

[Maykol Rojas]

Hello Ben,

It really depends on how is everything setup and what is your final goal. If you have an infrastructure already in place and you want to introduce the firewall without making a lot of changes, I think Transparent will work for you just fine.

Cheers.

Mike

[Panos Kampanakis]

To add to MAykol 's suggestion:

Transparent FWSM will bridge 2 vlans and it is will "transparent to the users. They will be sending packets to the same MAC addresses they were sending before and the FWSM will "silently be in the middle".

In router mode the FWSM is a Layer3 hop in the middle and the hosts should be sending to it as a gateway or at least the FWSM will be in the path a layer 3 hop.

Keep in mnd that there are some features that are not supported in transparent mode which you can read here http://www.cisco.com/en/US/docs/security/fwsm/fwsm40/configuration/guide/fwmode_f.html#wp1222079

I hope it helps.

PK