ADSL failover scenerio

Hello Everyone,

I want to discuss a scenerio is which i have to distribute traffic incoming
from 3 different VLans, to three ADSL links and one leased line. i was able
to distribute traffic from all these vlans using policy based routing and by
distributing clients onto these circuits on odd and even ip basis. Below is
the clarification.

ADSL1---> Even Students,
ADSL2---> Odd Student
ADSL3---> Even Staff, All Guest
LL----------> Odd Staff

After achieving this, the requirment is to perform a failover of internet
traffic to another link incase any of these link fails. Like if ADSL1 fails,
the even students internet traffic should automatically start passing
through ADSL2 that is used for odd students and vice versa. Same goes for
Staff and Guests. I thought that i can achieve this using ip sla. I created
ip sla's for testing a icmp to a internet address using one of the inside
interface through the gateways of each dsl and lease line circuit. I made a
track object to check for the status. But now the problem is that how can i
use this tracking object to change policy based routing desicion. Is there a
way to use this track object inside route-map? Below is the hint of my
configuration.

This is one of the three IP sla for a adsl circuit test.

ip sla 1
 icmp-echo 8.8.8.8 source-ip 10.10.34.140 [lan ip adsl router 1]
 threshold 500
 timeout 1000
 frequency 1
ip sla schedule 1 life forever start-time now
!
track 1 ip sla 1 reachability
delay down 10 up 10
!

How can i use it to change the decision in the below route-map, so if there
is no icmp recieved from 8.8.8.8 using source ip of 10.10.34.140 it should
send the request to the other adsl router 10.10.34.141.

ip access-list extended STAFF_ACL_EVEN
 permit ip 10.10.12.0 0.0.0.254 any

route-map INTERNET_POLICY permit 10
 match ip address STUDENT_ACL_EVEN
 set ip next-hop 10.10.34.140
!

I hope someone had some experience doing this.

-- 
Khurram Noor
CCIE # 24419
http://www.linkedin.com/in/khurramnoor
Blogs and organic groups at http://www.ccie.net