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Tracked default route is not in the routing table

Julian Ortiz
Level 1
Level 1

Hi guys,

 

I have a default route which is tracked, the track is up, but the route is not being placed in the routing table. I copy only the relevant configuration:

 

!

track 1 ip sla 1
  delay down 9 up 3

ip route 0.0.0.0 0.0.0.0 10.20.15.1 track 1
ip route 0.0.0.0 0.0.0.0 10.20.16.4 50
ip route 0.0.0.0 0.0.0.0 172.19.12.1 100
ip route 192.168.40.253 255.255.255.255 172.19.12.1
!
!
ip sla 1
  icmp-echo 192.168.40.253 source-ip 172.19.12.243
  frequency 5
ip sla schedule 1 life forever start-time now
access-list 101 permit ip host 172.19.12.243 host 192.168.40.253
!
!
route-map ping_ipsla permit 10
  match ip address 101
  set ip next-hop 10.20.15.1 172.19.12.1

!

As said, the IP SLA returns OK and the track is up:




SALV_ROUTN1_12.243#show ip sla summary
IPSLAs Latest Operation Summary
Codes: * active, ^ inactive, ~ pending
All Stats are in milliseconds. Stats with u are in microseconds

ID Type Destination Stats Return Last
Code Run
-----------------------------------------------------------------------
*1 icmp-echo 192.168.40.253 RTT=20 OK 1 seconds ago




SALV_ROUTN1_12.243#show track
Track 1
IP SLA 1 state
State is Up
16 changes, last change 00:28:12
Delay up 3 secs, down 9 secs
Latest operation return code: OK
Latest RTT (millisecs) 20
Tracked by:
Static IP Routing 0


The only thing I am thinking is tight now I don't have a route for 10.20.15.1, but I don't think this should be the problem. What am I missing?

 

Regards,

Julián

1 Accepted Solution

Accepted Solutions

Jon Marshall
Hall of Fame
Hall of Fame

 

What do you mean by "you don't have a route to 10.20.15.1" ? 

 

If you mean the router does not have a directly connected interface in that subnet (10.20.15.x) and it cannot recursively resolve that next hop IP then it won't install the route in the routing table whether the track works or not. 

 

The router has to be able to reach 10.20.15.1 before it can use it as a next hop IP address for your default route. 

 

Jon

View solution in original post

6 Replies 6

Jon Marshall
Hall of Fame
Hall of Fame

 

What do you mean by "you don't have a route to 10.20.15.1" ? 

 

If you mean the router does not have a directly connected interface in that subnet (10.20.15.x) and it cannot recursively resolve that next hop IP then it won't install the route in the routing table whether the track works or not. 

 

The router has to be able to reach 10.20.15.1 before it can use it as a next hop IP address for your default route. 

 

Jon

Hi Jon,

 

Then that should be the reason. I have a interface in subnet 10.20.15.x/24, but it is shutdown, because the other ISP end (10.20.15.1) is currently down. If I no shutdown this interface, it will not reach 10.20.15.1 (because is currently down), the IP SLA will return timeout, and the track will be down, so the route won't be in the routing table either. I will no shutdown the interface once the ISP fix his end, then the route should be install in the routing table. Many thanks for your help, I needed this refresh about the routing table and the recursive lookup.

 

Regards,

Julián 

Hi,

 

Just checked and when I no shutdown the interface in the 10.20.15.x network, the default route was placed in the routing table. Then that was the reason

 

Regards,

Julián

Defualt route is up

Next hop is up

Track is up

 

As i mention before and according to your original post (track is up) how track up and route is missing????

Your config is wrong.

Just to make sure only shut down 

172.19.12.1
You will loss defualt route.

ip route 0.0.0.0 0.0.0.0 10.20.15.1 track 1
ip route 0.0.0.0 0.0.0.0 10.20.16.4 50
ip route 0.0.0.0 0.0.0.0 172.19.12.1 100
ip route 192.168.40.253 255.255.255.255 172.19.12.1<- change this to 10.20.15.1
!
!
ip sla 1
  icmp-echo 192.168.40.253 source-ip 172.19.12.243

track is up becuase you use static route toward different next hop than defualt route next hop use the track that the reason.

Image the isp is down if your config right then track must detect it,

You config is wrong find above how you correct it.

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