Bug #18
closed
Link loss can cause multi-WAN difficulties
Added by Chris Buechler almost 15 years ago.
Updated about 14 years ago.
Description
When you lose link on a NIC assigned as an OPT WAN, the static route that directs the monitor IP out the correct WAN may get dropped from the routing table, causing the monitor pings to follow the default gateway. Generally not an issue as a WAN failure rarely results in link failure, but something we need to address in 2.0.
Maybe the source address should be used for the icmp packets to make sure that it tries to go the correct interface!
For 2.0 that means that apinger sources might need modification(usually just try to bind to the source ip).
Source address alone isn't adequate, as that traffic will still follow the system routing table even when sourced with an OPT WAN's IP. A route-to rule is a possible solution I think, haven't had a chance to try.
- Affected Version set to 2.0
Patch added to prevent the removal of static routes upon interface link loss. This is also similar to #72 ?
- Status changed from New to Resolved
This has been resolved with my recent change. I just tested by pulling my Wimax network interface and the static route remains in the routing table and works as it should.
- Status changed from Resolved to Feedback
This needs more testing, and possibly a different solution, depending on how the routing functions in FreeBSD 8 and what unknown fallout there may be.
The code in filter.inc needs to be updated to never add a gateway on an interface that doesn't have link to help with this scenario.
- Status changed from Feedback to Resolved
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Updated by Ermal Luçi 
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