Firewall That'll Replace ISA Server 2003

We have a 2003 ISA Server that's blocking a specific group of users from our network. The ISA server is also being used as a router.

What cisco firewall is there if any that might fulfill the same duties?

Will just about any firewall do? Can I just filter the mac address for the stations I want to block from the internet.

hi.
It depends about what are you doing now in your isa server? how many connections are crossing it? Mean the weight of your company.
at the pix you can also filter by mac-address.

try cheking by yourself at cisco.com, so you are the only who knows about your network, you must select what is the best product for you.

regards.