EIGRP over NAT

[Shtou]

Hello everyone, i have an issue with a remote location, accessible for me from 2 providers, to make it work, i use EIGRP on both linked, i used bandwidth and delay to make the links have the desired order on my hub router, the issue is that i use NAT on the remote location

to make eigrp work through NAT i used ip route 192.168.1.0 (inside global ip class) 255.255.255.0 null 0 so that EIGRP can promote the network, but the issue is that if the link to the local network fails he still promotes the network, even if the physical interface is down

can i connect someway the local physical interface to the route i made using null0 interface, so that router promotes link only when physical interface ip up?

[Shtou]

i was thinking about using track, to report route only when track detects physical link up, but dont know the right way to configure it

[Shtou]

yes, track worked over static route with null interface

[Georg Pauwen]

Hello,

so you got it to work ? If not, post the full configs...

[Julio E. Moisa · Accepted solution]

Hi,

I remember conditional advertisements in OSPF and BGP, you could use an EEM Script to avoid advertise the network once the link is down and restablish once it is up. Components:

- IP SLA

- Track

- EEM Script.

ip sla 10
icmp-echo <ip de destino> source-interface <source interface to make ping>
frequency 5

ip sla schedule 10 life forever start-time now
ip sla logging traps
ip sla enable reaction-alerts

track 10 ip sla 10 reachability
delay down 10 up 10

Some command lines could change per IOS images

Example:

track 10 rtr 10 reachability instead: track 10 ip sla 10 reachability

it will a generate a message like:

*Mar 1 00:08:15.371: %TRACKING-5-STATE: 10 rtr 10 reachability Up->Down

A basic example is the following, you can customize it:

event manager applet MI-SCRIPT
event syslog pattern "%TRACKING-5-STATE: 10 rtr 10 reachability Up->Down"
action 1 cli command "enable"
action 2 cli command "configure terminal"
action 3 cli command "interface fa0/0"
action 4 cli command "shutdown"
action 5 cli command "exit"
action 6 cli command "write memory"

Hope it is useful

:-)