IP SLA out the Internet

[Michael Durham]

We are using IP SLA to watch our two Internet connections. When I configure the SLA as follows it never comes up:

ip sla 1
 icmp-echo 4.2.2.2 source-ip 192.168.254.1
 threshold 750
 timeout 900
 frequency 1
ip sla schedule 1 life forever start-time now

But if I config it this way it does.

ip sla 1
 icmp-echo 192.168.254.254 source-ip 192.168.254.1
 threshold 750
 timeout 900
 frequency 1
ip sla schedule 1 life forever start-time now

192.168.254.254 is my edge router to the Internet. 

I need the SLA to test out to make sure my ISP is providing working Internet, not that my edge router is running.  Any suggestions as how to configure the SLA to meet my needs?

Thanks

[Jon Marshall · Accepted solution]

Michael

Using you other post as a guide it looks like you are translating all internal subnets to the 192.168.254.1 IP on the 2851 so the edge router must be doing NAT for that IP otherwise you would have no internet access.

So assuming it is then it must be due to routing ie. when you ping 192.168.254.254 that is in the same IP subnet so it knows where to send traffic.

When you ping 4.2.2.2 it must use the default route and again checking your last post that is pointing to the 192.168.0.254 although that may be because you shut down 192.168.254.254 for testing ?

So basically NAT or more likely routing.

What you could do to test is add this to your 2851 -

"ip route 4.2.2.2 255.255.255.255 192.168.254.254"

Jon

[Michael Durham]

Routing, and the worked!  I wish I had your smarts!  Thanks so much.  Now only one issue left, CME call forwarding had no audio. Already started a post on that one.

Again, thank you so much!!!