Firewall check
from an external host, e.g. lxplus, run
nc -v4z <server> 1094
nc -v6z <server> 1094
example:
nc -v4z ceph-svc16.gridpp.rl.ac.uk 1094
Network trace (network instability/connectivity issues against some other sites)
from a failed FTS transfer, get the destination URL from one of the logs and get their endpoint
login to one of our servers
do
traceroute <endpoint>
traceroute6 <endpoint>
example:
traceroute cephc04.gla.scotgrid.ac.uk
and check where/if the traffic disappears ( listed as **** until it hit the 30 max hops)
the problem also may be on their end, in which case you can ask them to traceback with the same commands to one of our servers