Connected node would remain in "alive" state indefinitely after unplugging Ethernet cable connecting two agents

[ashuels]

I hit a potential issue where if I unplug the Ethernet cable connecting two nodes the interface would go down resulting in the serf pings failing to send with the error "[ERR] memberlist: Failed to send ping: write udp [::]:8001->10.7.32.148:8002: sendto: network is unreachable". However this error did not result in a member update event indicating that the connected node was no longer alive.

[ashuels]

The code where the failed ping does not get added to the suspect message is here