×

Warning message

  • Cisco Support Forums is in Read Only mode while the site is being migrated.
  • Cisco Support Forums is in Read Only mode while the site is being migrated.

ip sla source-interface

Unanswered Question
Oct 2nd, 2013
User Badges:

I'm looking for some clarification on ip sla and track operation specifically with respect to the outbound interface of the sla icmp-echo target.  If the source-interface is specific in the ip sla configuration, i.e.


ip sla 1

icmp-echo a.b.c.d source-interface gig0/0

ip sla schedule 1 life forever start-time now

track 1 ip sla 1

!

ip route 0.0.0.0 0.0.0.0 <next-hop> track 1


Is this configuration sufficient to forward the sla packets outbound on gig0/0 and to the next-hop as configured in the default route, assuming the next-hop is directly connected to gig0/0?  Does configuring the track statement with or without the reachability option have an impact on the outbound interface?


or


In order to ensure the outbound interface of the icmp-echo target, is a host route configuration required?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
rfalconer.sffcu Wed, 10/02/2013 - 08:45
User Badges:
  • Bronze, 100 points or more

If the next-hop is directly connected, your router will see it in the routing table as being directly connected as long as gig0/0 is up.

Directly connected networks will not be influenced by a default route since the default is used only when the router doesn't know where to send traffic.


Sh ip route:

C        a.b.c.x/x is directly connected, Gig0/0

pperreault Wed, 10/02/2013 - 09:15
User Badges:

I may not have been clear in my description.  The next-hop is our ISP gateway but the icmp-echo target is a host *behind* the ISP which obviously needs to be routed through the next-hop.

rfalconer.sffcu Wed, 10/02/2013 - 09:23
User Badges:
  • Bronze, 100 points or more

Understood, the icmp target is not a directly connected network to the router.

As you have it set, it will take the outbound interface of the default route.


If you have multiple external interfaces on the router that you want to work with, you can look at IP SLA used with policy based routing.

Actions

This Discussion