Custom monitor IP route not reinstated after interface transition
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I'm on pfsense 2.6.0 on generic amd64 build.
My broadband link is DHCP based, and I've set a custom "Monitor IP" to an ISP-specific external IP on that link, since the actual ISP gateway doesn't answer reliably to icmp probes.
There was an outage today, and the interface showed 0.0.0.0 for a while (so likely an interface transition with DHCP not answering for a while).
After the interface came back, and got its (same) IP back, pfsense monitoring logic continued to consider the interface down with 100% packet loss.Checkin on the firewall for traffic with the monitoring IP (tcpdump), I saw pfsense was actually performing ARP requests for the monitor-IP, which was bogus because that IP is NOT part of the interface IP range.
Doing a route check showed:
[2.6.0-RELEASE][admin@pfSense.localdomain]/root: route -n get MONITORIP
route to: MONITORIP
destination: MONITORIP
fib: 0
interface: igb3
flags: <UP,HOST,DONE,STATIC>which is clearly wrong, it should "route to" the DHCP specific gateway instead.
I've for now configured a static route, but I don't know whether that is going to exhibit similar problems if there's another outage, since it's also tied to the DHCP gateway.What I'd expect to happen: if there's an interface transition, a monitor-IP to an IP that is not "connected" (part of the interface) needs to be explicitly reinserted by pfsense once it detects the interface is back operational.
The whole problem sounds related somehow to https://redmine.pfsense.org/issues/11142
Cheers,
Markus