The net_connect logs are full of DNS lookup failed on hub3A which is a windows server


Article ID: 192750


Updated On:


NIMSOFT PROBES DX Infrastructure Management


I'm seeing a lot of DNS lookup failed on hubXX which is a windows server. When I do an nslookup on the name that failed in the net_connect log, in a command prompt on the server it resolves. Why are the names not being resolved by the probe?


- Environmental/DNS changes/server decommissioning


Release : 20.1



In the Prod environment, some servers are resolved via Windows DNS and others are resolved via BIND (Linux, AIX, Solaris, etc.) The number of failures in the net_connect log and therefore traffic generated due to net_connect retrying the ping to the server were caused by various factors.

- Failed lookups due to server decommissioning (server no longer exists, and should be removed from monitoring)
- Failed lookups due to change in server domain, e.g., xxxxnez1 (Windows servers), to xxxxnez2 (UNIX, Linux, AIX, Solaris machines)
- No ticket(s) opened for DNS changes not being reported immediately to the UIM Administrator by the DNS team

For now customer can change the retries setting in net_connect to 0, to minimize the effect n the server - being hammered by continuous connection attempts due to consecutive failed lookups. When the DNS/environmental issues are resolved, the retries can be reset to 1, 2 or 3 when the changes are reconciled.