router/fw setup

[carl_townshend]

Can anyone tell me why most people have a router in front of the fw, as the firewall can route ? is it because routers support routing protocols etc ? and have the right serial/atm connections etc ?

[mmorris11]

Usually because of layer 2. So if I have an internet service via T1, I need a router as you cannot connect a T1 directly to a firewall.

HTH

[m-haddad]

Different reasons behind that below you can find some:

1- As stated before maybe the physical termination is an E1, T1, or Serial which is not supported on Pix/ASA firewalls

2- Firewalls can do basic routing and PIX/ASA support OSPF only. I am not sure if ASA do support BGP

3- PIX doesn't support ISP multi-homing, and ASA do support this functionality but is also limited

4- Offloading the firewall from routing processing

5- Policy based routing is done the router where more than one ISP terminates

Please rate if you find the above helpful,

Regards,