NAT Advertisement through EIGRP

ccie1yrccie1yr Member Posts: 19 ■□□□□□□□□□
in CCIE
All,

Another scenario where I need help.

I am performing NAT on a router and would like to know how can I advertise NAT IP address through EIGRP?

R1
R2 (NAT)

R2 real IP -192.168.1.1
R2 NAT IP - 10.10.1.1

Question is how to receive 10.10.1.1 on R1 through EIGRP.
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Comments

  • stuh84stuh84 Member Posts: 503
    I'm not 100% sure, but could you set up a loopback with an address from the same subnet, set it as a NAT inside interface, and advertise out that interfaces network?
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  • ccie1yrccie1yr Member Posts: 19 ■□□□□□□□□□
    stuh84 wrote: »
    I'm not 100% sure, but could you set up a loopback with an address from the same subnet, set it as a NAT inside interface, and advertise out that interfaces network?

    Thanks, I was thinking the same, and actually loopback interface doesn't need any NAT configuration. I can just advertise that interface in EIGRP.

    Does anyone have any other experience?
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  • deth1kdeth1k Member Posts: 312
    ccie1yr wrote: »
    Thanks, I was thinking the same, and actually loopback interface doesn't need any NAT configuration. I can just advertise that interface in EIGRP.

    Does anyone have any other experience?

    So where are you NATTING to and what are you trying to achieve, is there a 3rd router involved in this? Are you NATTING from 10 network to 192, if so there is no need for router 1 to know about network 10.
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  • ccie1yrccie1yr Member Posts: 19 ■□□□□□□□□□
    deth1k wrote: »
    So where are you NATTING to and what are you trying to achieve, is there a 3rd router involved in this? Are you NATTING from 10 network to 192, if so there is no need for router 1 to know about network 10.

    I am NATTING from 192.x network to 10.x network and wants to receive 10.x network onto R1 through EIGRP.

    No other router is involved in this environment.
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  • deth1kdeth1k Member Posts: 312
    ccie1yr wrote: »
    I am NATTING from 192.x network to 10.x network and wants to receive 10.x network onto R1 through EIGRP.

    No other router is involved in this environment.


    Do you have the two routers in different subnets is that what you mean?
    Can you advise what ip addresses are used for R1?

    Thanks
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  • burbankmarcburbankmarc Member Posts: 460
    I know this has been answered but when I need to do something like this I just create a static route to null and then redistribute that into the routing protocol.
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  • ccie1yrccie1yr Member Posts: 19 ■□□□□□□□□□
    deth1k wrote: »
    Do you have the two routers in different subnets is that what you mean?
    Can you advise what ip addresses are used for R1?

    Thanks

    router.png

    Diagram shows the IP addressing scheme, I am performing NAT on R2 router to move 192.168.1.x network to 10.10.1.x network.
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  • ccie1yrccie1yr Member Posts: 19 ■□□□□□□□□□
    This is what I have done till now. All these solution works, do let me know if something else can be done.

    1. Create loopback interface and assign it to the same IP range, than advertise the range through EIGRP
    2. Create static route pointing to null, and advertise it through EIGRP by network statement.
    3. Create static route pointing to null, than redistribute static route to EIGRP. Only problem is you will end up redistributing all static routes and to restrict the same you have to use route-map.

    My personal fav is 2nd step, as it require minimum configuration and less admin work.
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