• Creator
  • #2200567

    Cisco IOS NAT/Dynamic routing


    by jimmie ·

    Need to figure out a way to dynamically tell the best path (router is down), while using NAT. We have 2 Internet routers (1 for ISP-A, and 1 for ISP-B) which does nothing except static routes to the Internet. Have a Cisco router underneath leading into LAN that handles NAT. We NAT/route out to ISP-A statically right now, but need to add redundancy in to ISP-B (all 3 Cisco routers, 1841 will have 3 interfaces, 1 to LAN, 1 to ISP-A router, and 1 to ISP-B router). I can get EIGRP working between them, but as soon as I re-apply NAT statements on the 1841 EIGRP stops working. Anyone have a better solution or a way to fix this one?

    (—) (—)
    (ISP-B) (ISP-A)
    (___) (___)
    \ /
    \ /
    \ /
    \ /
    \ /
    NAT out \(—)/NAT out
    (1841 )
    |NAT in

All Answers

  • Author
    • #2758727


      by jimmie ·

      In reply to Cisco IOS NAT/Dynamic routing


    • #2758716


      by netman1958 ·

      In reply to Cisco IOS NAT/Dynamic routing

      I am assuming the following, correct me if I am wrong:
      (1)The 2 routers that connect to the ISPs have public IPs on their outside interfaces and a private IP on the interfaces that connect to the inside.
      (2)Both interfaces on the router performing NAT have private IPs

      If this is correct, you need to disable NAT on the router that is closest to the LAN, and enable NAT on each router that connects to an ISP.

    • #2758668

      Question: EIGRP between interfaces? or routers?

      by cg it ·

      In reply to Cisco IOS NAT/Dynamic routing

      are there any neighbors in the table?

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