Resolved: CACTUS service unavailable
The service CACTUS had an issue with its Etherchannel network connection at 5:31 PM. While both links were up, it would not pass traffic on the one which was primary. We disabled both links and then enabled just one and the network connection started working. The service was back at 6:34 PM. We have since moved CACTUS to another server that has properly working Etherchannel.