Cisco 1841 with dual cable modems and multiple IP

[jasonmichel]

Ok, we currently have an 1841 with a dialer card in it for our DSL, we recently upgraded to cable inet. we have 2 modems and a total of 20 IP from ISP. We got the second modem for another company in our building that only needs 1 static IP. Our 1841 has the 4 port switch addon card. How can i segment the 1 static IP to go to their linksys router they are using and have the remaining pool be in a block for our use? Thanks in advanced

 

[North323]

policy based routing

 

[jasonmichel]

can you give me and explantion/example. never done before, what i was thinking about doing was putting a switch to run both modems into and then run lines from there to the routers, but i'd be interested in seeing what you are talking about

 

[Kajitora]

As North pointed out you could use policy based routing, but that may be a little complicated. I would suggest a simple nat solution. You would assign a private Ip address to the linksys router and then Nat it to the single public that you want to give to them.

So it would look something like this:

int fa0/1
ip nat inside
ip address 10.1.1.1

int atm0/0/1
ip nat outside
ip address (Public address used for internet access)

ip nat inside source static 10.1.1.10 (Public address for linksys)


For more Nat information check this out:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094e77.shtml

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Your desc was a bit vague so if I am way of track here let me know.