Hi,
As part of internal cybersecurity practices, our servers are subjected to regular vulnerability scans. On a recent scan, the scan result contained "SNMP Agent Default Community Name (public)" vulnerability. This basically means that there's an SNMP Agent listening to the default community name of "public".
After a check, I can reasonably conclude that DataMiner is the one listening on port 161. Is there anyway we can change the default community string to something else?
FYI, this DMA also has elements that communicate with devices via SNMP.
Thanks in advance.
Hi Andrew,
It is possible to change the default community string to something else. You can find more information here: Configuring SNMP agent community strings | DataMiner Docs
Now, security wise, it would even be better to just close that port altogether. The SNMP Agent of a DMA is listening on port UDP 161, and by default the recent installers of DataMiner keep this port closed by default. This SNMP Agent is typically not being used, because you only need this when an external system would need to query things from DataMiner over SNMP. This hardly ever happens, so you can typically close this UDP port 161.
Closing UDP port 161 has no impact on elements polling SNMP devices. DataMiner uses its SNMP Manager to poll SNMP devices. To poll an SNMP device, no port needs to be open on a DMA, because you only have an outgoing request to the SNMP device with a reply on that request. If the device does send SNMP traps or inform messages, then UDP port 162 must be opened on the DMA. Then the SNMP Manager of DataMiner will listen on that port for incoming traps.
So, in short, the SNMP Agent on a DMA is just listening on UDP 161 for external systems querying DataMiner. This is rarely being used and therefore UDP 161 can typically be closed. The SNMP Manager on a DMA is the one doing all the hard work to poll all the SNMP devices. Polling is possible without the need to open incoming ports. Only when you need to receive traps on DataMiner, you need to make sure UDP 162 is open so that the SNMP Manager on DataMiner can receive traps.
Let us know if something would not be 100% clear.
Bert
Hi Andrew,
I think this is what you are looking for: https://docs.dataminer.services/user-guide/Advanced_Functionality/SNMP_managers/Configuring_SNMP_managers/Changing_SNMP_agent_ports.html
Hi.. Thanks for pointing me in the right direction. I have managed to achieve what I wanted to do.
Hi Bert,
Thanks for your explainer and the link to the resources. I have managed to achieve what I wanted to do. In the end, I disabled the SNMP Agent functionality on my Agents as I needed port 161 for the operating system.
Regards,
Andrew