Configure Cisco 2801, Juniper Firewall and DSL modem on same subnet

[m.aslam]

Hello,

I'm trying to setup a new branch office with a DSL Modem, Firewall and MPLS connected to a cisco 2801. I have a /29 IP block from my dsl provider. Since the router is going to have one interface to the Modem and another to the firewall, is it possible to assign one IP to each and have rest available for servers behind the firewall? Or do i need to break the /29 into /30 netblocks?

[thiru.vel10]

HI,

2801 router is directly connected in DSL modem. In this router having two Fastethernet interface so you configure one public IP address in that interface and put one hub to connect the firewall and server. Local LAN is connect to Firewall LAN . I hope this is cleared your doubt

[m.aslam]

thanks for your reply. i understood the first part where you suggested putting a public ip for the first interface. But i'm not clear on how to put a hub and connect the firewall ans server? could you explain a bit more?

[thiru.vel10]

Configure the Public IP address in one Ethernet interface in Cisco router , and put one Hub that is connected to Ethernet interface for Cisco router, then now you connect the firewall and server in HUB and configured the Public IP address in server and Firewall WAN interface. For more information please see the PDF.

[m.aslam]

Thanks. I have attached a diagram of what i wanted to do if possible. Instead of connecting a hub/switch in the mix, is there a way to connect the firewall on the other FE interface of the router and have the router act sort of what the hub would be doing?

[thiru.vel10]

Hi I saw the Diagram which you attached. How many fastethernet interface you are having in Cisco router? You would connect the server and LAN switch in Firewall lan interface. Then all the traffic going through firewall. I think in firewall having port forwarding option so it very easy give the server access out.

Note: if you put Hub in between the cisco router and forewall means you can use all the public Ip address. For example if you want to connect the wireless access point , voice over IP phone, webserver etc.