Redundancy through IPsla with two default routes for two different ISP not working

[rituporna111]

Hi Team,

We have a requirement to setup redundancy for two different ISP.

The configuration is below,

Int gi0/0 (primary ISP)

ip address 10.10.10.10

int gi0/1(seconadary isp)

ip address 20.20.20.20

ip sla 1
icmp-echo 10.10.10.1 source-interface gi0/0
timeout 5000
frequency 5
threshold 500
ip sla schedule 1 start-time now life forever

track 10 ip sla 1 reachability

ip route 0.0.0.0 0.0.0.0 10.10.10.1 track 10
ip route 0.0.0.0 0.0.0.0 20.20.20.1 5

R1#show ip route track-table
ip route 0.0.0.0 0.0.0.0 10.10.10.1 track 10 state is [up]

We can ping the secondary gateway 20.20.20.1 .

The issue is when I tried to shut gi0/0, the alternative link that is 20.20.20.X link is not getting up.

R1#show ip route track-table
ip route 0.0.0.0 0.0.0.0 10.10.10.1 track 10 state is [down]

Thanks and regards,

Rituporna Sarma

[Mark Malone]

Hi can you change the timers to this and test again

timeout 1000

thres 2

freq 5

[rituporna111]

Thanks  Mark,

timeout 1000 not accepting.

(config-ip-sla-echo)#timeout 1000
%Error: timeout is less than threshold 5000

But I need to tell you one more thing.In those gi0/0 and go1/0 nat overload is configured.the command I configured is-

route-map ISP1 permit 111
match ip address 111
match interface gi0/1
!
route-map ISP2 permit 111
match ip address 111
match interface gi0/0

ip nat inside source route-map ISP1 interface FastEthernet0/1 overload
ip nat inside source route-map ISP2 interface FastEthernet0/0 overload

Thanks and Regards,

Rituporna Sarma

[Mark Malone · Accepted solution]

Hi that should work prob have to delete the ip sla first ,  the reason I gave those is I know they work and yours says timeout 5 seconds , fre 5 seconds and threshold .5 of second  you could try speed them up and if that does not work slow it down sometimes the timers can be the cause of the ip sla not kicking in depending on software

is that just a typo in nat overload rule you have fastethernet ports ?

if it is does the nat work on when not in failover state on the 20 subnet if you wree just using it normally without ip sla ?

[rituporna111]

Hi,

With ip sla its working fine.

I reduced the timers and now its working fine.

[rituporna111]

Hi Mark,

The redundancy is working fine now :-)

Thanks for your support.