Network Problem

[Namekian]

My Cisco router isn't going to be able to preform my wanted duties, so I am going to have to place my Firewall on the outside, and I don't know how to set it up as.

I have 5 public ips and a gateway for them. How can I set one port on a Cisco PIX 512 Firewall to handle all five IPs and the gateway?

 

[lgarner]

Assign one of your public IPs to the outside interface, set the default route to be your gateway device (The ISP's router, for example) and you're set as far as the networking goes.

I'm not sure I know what you mean by "handle all five IPs". If you mean that you have internal servers which need to be available from the Internet, then you use a static NAT statement and an access-list entry. Each interface on the Pix normally has only one address assigned to it.

 

[Namekian]

I have five public IPs. For instance 1.1.1.1, 2.2.2.2, 3.3.3.3, 4.4.4.4, 5.5.5.5, but I only have one line coming from the wall. Another issue is that the building that our office is in, supplies the connection via a switch port. Meaning we don't have access to the modem directly. I need to be able to use all 5 IPs, but I can only use one port to connect it all to the outside. So, I can only use a port on the router or the firewall.

The router doesn't seem to like it, but I could just be doing the command wrong. I am using the secondary IP option to assign 5 IPs onto one port.

 

[lgarner]

Sorry, I thought you meant 5 separate addresses on the same network, not 5 separate networks. I think the Pix can do this via VLANs, but I haven't done it myself.

Routers can do this via "ip secondary", but routing becomes an issue. For example, you must have 5 gateways to the Internet- which one should be chosen. You might have to look into policy-based routing. From my understanding, an IOS router will be more flexible in this than a Pix.

 

[Namekian]

I thought so at first also, but it didn't seem to like it when I placed the five IPs in there. I have a gateway also, how would I make it so that I use the gateway, and use the 5 IPs. I cant do VLANS, to old of a switch, it is a Cisco Catalyst 5000.

 

[lgarner]

You can't. For example, you can assign different networks to an interface:

int eth 0
ip address 192.168.1.0 255.255.255.0
ip address 192.168.2.0 255.255.255.0 secondary
ip address 192.168.3.0 255.255.255.0 secondary

But you get only one default gateway, and it has to match one of the networks that you're interface is configured for.

Network 192.168.1.0/24 can't route via 192.168.2.1, for example.

I'm still confused on what you're trying to do. How does traffic for all 5 networks get to you through 5 different gateways?