Proxy Server in DMZ - Bottleneck on FWSM??

ben_johnson · ‎08-17-2010

Hi all,

Just after some opinions or, even better, experience.

The web proxy server where I work currently exists within the organisations internal LAN structure (ie. traffic going to the proxy server from within the organisation does not cross the firewall). I'm wanting to move the proxy server into the security zone where the rest of our public-facing services live - notionally the DMZ. However, this will mean that all traffic from the internal networks going to the internet will cross the firewall twice in each direction, instead of once. For example:

CURRENT SITUATION:

Internal networks --> Proxy --> [ Firewall ] --> Internet

PROPOSED SITUATION:

Internal networks --> [ Firewall ] --> Proxy --> [ Firewall ] --> Internet

Does anyone know if this will pose a problem for the FWSM (SW 2.3) and therefore a noticeable performance hit for the users?

Thanks in advance,

Ben.

Yudong Wu · ‎08-18-2010

What's your traffic load on the proxy server?

FWSM has 6 X 1 gig links to connected to the switch backplane.

ben_johnson · ‎08-18-2010

We're going through the process of upgrading the proxy server hardware at the moment, but an important point that I left out is probably that we're 100Mbps to the desktop for all clients and that the speed of our internet connection is only 100Mbps also. As we expand however, the speed of the internet connection will certainly grow to 1Gbps and beyond.

Currently, and for the near future, the proxy has one NIC connected to a 1Gbps interface on a switch in the data centre.

I'm interested in whether making this change now would have any discernable effect from the perspective of our users, as well as whether the firewall can handle it (which it probably can, given the backplane connections you've mentioned).

Cheers,

Ben.