Traceroute Vs Netcat

Hello Everyone,

I have two RHEL 7 servers on an private network where Traceroute can reach a port but Netcat cannot. I don't see any SELinux messages (/var/log/messages) or anything in the firewalld logs either. I believe that this is related to why the (Slurm) nodes in our cluster can't communicate with each other. Here is an example:

$ sudo nc -zv 172.30.0.186 6818 Ncat: Version 7.50 ( https://nmap.org/ncat ) Ncat: Connection refused. $ sudo traceroute -T -p 6818 172.30.0.186 traceroute to 172.30.0.186 (172.30.0.186), 30 hops max, 60 byte packets 1 172.30.0.186 (172.30.0.186) 0.105 ms 0.106 ms 0.103 ms 

Note that I am not ruling out that this could be a firewall or an SELinux issue. Does anyone have any ideas on how to troubleshoot this?