I have configured a topology which contains ip sla , route map , dual natting.It work perfect but when I used route map natting the eigrp become flapping and show the error is "retry limit exceeded". as shown in this image

Comp_R: configured Eigrp 10 between Comp_R and Tel_isp to reach to network on Tel_isp interface f1/0. configured ip sla on Comp_R Router to track if down then it will revert to Zon_isp. configured natting using route map on Comp_R Router.

 configuration on Comp_R Router:

 Comp_R (config)#Router eigrp 10
       Passive-interface f0/0 //no to send update on f0/0 

   Configure Ip sla and track 

      Comp_R(config)#ip sla 10
      Comp_R(config-ip-sla)#icmp-echo source-ip
      Comp_R(config-ip-sla-echo)#frequency 5
      Comp_R(config-ip-sla-echo)#timeout 5000 
      Comp_R(config)#ip sla schedule 10 start-time now life forever

  Now configure track

     Comp_R(config)#track 15 ip sla 10 reachability 

    Comp_R(config)#ip route track 15
    Comp_R(config)#ip route 10

 Configure Nat on Comp_R using route map

    Comp_R(config)#int f0/0 
    Comp_R(config-if)#ip nat outside 
    Comp_R(config)#int f1/0
    Comp_R(config-if)#ip nat outside 
    Comp_R(config)#int f2/0
    Comp_R(config-if)#ip nat inside 

    Comp_R(config)#route-map natfortelisp permit 10 // route map name your choice
    Comp_R(config-route-map)#match interface f0/0
    Comp_R(config)#route-map natforzonisp permit 10
    Comp_R(config-route-map)#match interface f1/0
    Comp_R(config)#ip nat inside source route-map natfortelisp interface f0/0 overload 
    Comp_R(config)#ip nat insdie source route-map natforzonisp interface f1/0 overload 

 configuration on Tel_isp Router:

 Tel_isp(config)#Router eigrp 10
     No auto-summary

Problem create when configured route map and eigrp show the following message

*May  3 07:34:40.059: %DUAL-5-NBRCHANGE: EIGRP-IPv4 10: Neighbor (FastEthernet0/0) is up: new adjacency
*May  3 07:35:59.579: %DUAL-5-NBRCHANGE: EIGRP-IPv4 10: Neighbor (FastEthernet0/0) is down: retry limit exceeded
*May  3 07:36:01.887: %DUAL-5-NBRCHANGE: EIGRP-IPv4 10: Neighbor (FastEthernet0/0) is up: new adjacency
*May  3 07:37:21.407: %DUAL-5-NBRCHANGE: EIGRP-IPv4 10: Neighbor (FastEthernet0/0) is down: retry limit exceeded

  checking Comp_R routing table it shows:

    Comp_R#sh ip eig nei
    EIGRP-IPv4 Neighbors for AS(10)
    H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                               (sec)         (ms)       Cnt Num
    0                Fa0/0                    13 00:00:46    1  5000  1  0

  Tel_isp Routing table:

  Tel_isp#sh ip ei nei
   EIGRP-IPv4 Neighbors for AS(10)

what I misconfigured,I am using eve-ng

  • You cannot NAT EIGRP (or most routing protocols). EIGRP uses multicast ( and its own transport protocol (88), but NAT does not work well with multicast, and it only works with TCP, UDP, and ICMP. If you need to use EIGRP across a NAT connection, then you need to use a tunnel that supports multicast, e.g. GRE.
    – Ron Maupin
    May 3, 2021 at 18:29
  • if i use port forwarding which declare that forward network without NAT because I advertise in eigrp May 3, 2021 at 19:13
  • You need to use a tunnel to have EIGRP work correctly across a NAT. It is pretty simple. The tunnel packets will be carried across the Internet, and the two sites see the tunnel as a directly connected point-to-point link.
    – Ron Maupin
    May 3, 2021 at 19:17
  • I don't like to ,to use eigrp but there is no other way to reach to to monitor ip sla readability. May 3, 2021 at 19:21
  • This looks like an X-Y problem. You should ask a question about the actual problem, not your proposed solution. You cannot actually run EIGRP across the public Internet. You really need to establish a tunnel to connect the two sites, then there are methods you can use for IPSLA monitoring, and you may not need EIGRP, but we would need to see the configurations to help with that.
    – Ron Maupin
    May 3, 2021 at 19:35


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