Try telnet on your listen port. It must be network issue due to port or firewall issue.
Sent from my iPhone > On Dec 22, 2017, at 5:28 PM, sat <sathish.al...@gmail.com> wrote: > > > > Hi, > > We have 3 nodes in cluster, we rebooted one of the cassandra VM, we noticed > nodetool status returning "UN" for itself and "DN" for other node, although > we observe gossip sync and ack messages being shared between these nodes. > > Issue in Detail > > Nodes in cluster > Node1 > Node 2 > Node 3 > > All above nodes formed cluster and nodetool status in all 3 machines were "UN" > > We rebooted Node 1 and restarted cassandra on node1, then we ran nodetool > status and observed > > Node 1 - UN > Node 2 - DN > Node 3 - DN > > However when we run nodetool status on other 2 nodes (Node2, and Node 3) they > claim all 3 nodes are "UN" > > We enabled "Trace" level and checked Gossip messages and noticed "SYN", "ACK" > and "ACK2" initiated and received messages in Node 1 for other 2 nodes, but > still nodetool status marks other 2 nodes as down. > > Please let us know how nodetool detects other nodes as "DOWN". Any help is > highly appreciated. > > Thanks > A.SathishKumar