FEATURE REQUEST - Probe with source-interface

[jayh]

I see a feature request section for the NV7000 series but not elsewhere. This feature would actually be useful for all platforms using AOS.

Scenario:

When building a redundant WAN setup, one uses a probe to ping the remote side of the primary link. Should the probe fail, the default route is withdrawn and the backup floating static default takes over. Besides switching the default route, there are several other cases where probing a link is useful to take action should it fail.

The issue:

AOS allows one to set the destination target as well as the source IP address with "source-address". This works when the primary interface has a static IP from the carrier. In many cases, particularly with cable modem service, DHCP is used to set the IP address supplied to the CE router.

If one sets the probe source-address to the dynamically assigned address and it later changes, then the probe will fail.

If one doesn't specify a source-address, then when the link goes down, the backup link will connect to the remote destination, the probe will again pass, and put the (failed) primary link back in service, causing the probe to fail again and causing the route to oscillate.

Proposed solution:

Create a configurable "source-interface" for probes that will initiate the probe from a specific interface regardless of the IP address assigned to that interface. If this were available, probes configured to test the link connected to a specific interface will work properly even if the IP address on that interface is dynamically assigned.

[Anonymous]

Jay,

Thanks for posting.  I may need to see a sample configuration of exactly what you are doing, so that I understand completely.  It is my understanding that in your scenario we just need to make sure we do not specify the source address, and we also need to make sure a local route map is in place such that the ping probe is only allowed out the interface to be tested.  This route map would prevent the probe ever using or "passing" on the backup link.  Please let me know if you are using the route map and still having issues, or I am just misunderstanding the issue entirely. You may also want to respond on this thread with the relevant configuration.

Thanks!

David