SNMP - cannot connect to remote agent

[Hirscher]

Hi,
before I describe my problem I have to say that you give a great support. I've read some other topics that helped me well to understand the handling of HM and just want to thank you for that.

To my problem:
I created a little test environment for SNMP checks. A server (Windows Server 2003 RC2 SP2), two clients (Windows XP Pro SP2) and the HM 7.00b (Windows XP Pro SP2) are connected, all have SNMP service installed and running, there are no firewalls, no anti virus scanners, the RMA states are operable in passive mode, connected in active mode.
First I did the SNMP checks with active RMA, because later in the productive environment, I have to pass at least two firewalls.
I created an account in the Connection Manager, entered IP, login, password and set all methods as default.
The agents on all machines are configured correctly, RMA tells me the connection is established and I get ping replies, WMI-responses etc.
The SNMP-gets to the two clients work fine, but to the server I just get timeouts and the error message: Cannot connect to remote agent.
For testing I also tried passive mode, but same thing. Just timeouts. For the get-request I set timeout up to 1 min. but no change.

The SNMP-test I created has to check the sysUpTime, so that no missing or false MIB could interfere (OID: 1.3.6.1.2.1.1.3.0).
At SNMP Credentials I created a standard profile with SNMP version 1; 2c or 3 make no difference for getting timeouts.

The network sniffer Wireshark shows the get-requests, but no responses. So the problem has to be on the server, hasn't it?
But I can't explain it. SNMP service is running, netstat shows the connection for port 1055 is open, firewall service is deactivated, agent is running... What am I doing wrong?

[KS-Soft Europe]

before I describe my problem I have to say that you give a great support. I've read some other topics that helped me well to understand the handling of HM and just want to thank you for that.

Thank you!
We appreciate your opinion.

I created a little test environment for SNMP checks. A server (Windows Server 2003 RC2 SP2), two clients (Windows XP Pro SP2) and the HM 7.00b (Windows XP Pro SP2) are connected, all have SNMP service installed and running,

Let's clarify it a bit. You installed RMA on each machine: two XPSP2 and one Windows Server 2003 RC2 SP2. HostMontor is running on another XPSP2 machine. Correct?
If the test should be performed by RMA, you have to select appropriate agent from "Test by" dropdown in "Test Properties" window of the "SNMP Get" test method. Have you selected proper agent? If RMA send request to SNMP service, that is running on the same machine as RMA, you may specify "localhost" into "Host[:port]" input box in "Test Properties" window.

The SNMP-gets to the two clients work fine, but to the server I just get timeouts and the error message: Cannot connect to remote agent.

This error means HostMonitor is unable to estabilish connection with SNMP agent on target machine (default SNMP port is 161). If you are sure firewall is off, it might be a security issue. Please verify the SNMP agent accepts packets from the IP's where RMA and/or HostMonitor is running.

The network sniffer Wireshark shows the get-requests, but no responses. So the problem has to be on the server, hasn't it?
But I can't explain it. SNMP service is running, netstat shows the connection for port 1055 is open, firewall service is deactivated, agent is running... What am I doing wrong?

Probably, SNMP agent on the server uses another port (default is 161)? You may launch "netstat -nao" command in command line prompt to figure out what exact process uses port 161 and what port is used by SNMP agent.

Regards,
Max

[Hirscher]

Let's clarify it a bit. You installed RMA on each machine: two XPSP2 and one Windows Server 2003 RC2 SP2. HostMontor is running on another XPSP2 machine. Correct?

Correct.

If the test should be performed by RMA, you have to select appropriate agent from "Test by" dropdown in "Test Properties" window of the "SNMP Get" test method. Have you selected proper agent? If RMA send request to SNMP service, that is running on the same machine as RMA, you may specify "localhost" into "Host[:port]" input box in "Test Properties" window.

Yes, that are the properties, I selected.

This error means HostMonitor is unable to estabilish connection with SNMP agent on target machine (default SNMP port is 161). If you are sure firewall is off, it might be a security issue. Please verify the SNMP agent accepts packets from the IP's where RMA and/or HostMonitor is running.

Security is configured so that the SNMP service allows connections from the HM and the community has rights to read and write.

Probably, SNMP agent on the server uses another port (default is 161)? You may launch "netstat -nao" command in command line prompt to figure out what exact process uses port 161 and what port is used by SNMP agent.

Used port by snmp.exe is 161.

I found additional info that maybe could help. Active RMA on the Server shows "SNMP test .. error"
If I open MIB Browser, select sysUpTime and click on GetNext, I get the error mentioned above. If I perform the test I get the reply "SNMP error: Invalid response from SNMP agent" Does this mean the same?

[KS-Soft Europe]

Security is configured so that the SNMP service allows connections from the HM and the community has rights to read and write.

Ok. What about IP's of the machine, where RMA is running? Have you included it into the SNMP Service's accepts list? The test is performed by RMA, so RMA sends SNMP request from the machine, where it is running.

I found additional info that maybe could help. Active RMA on the Server shows "SNMP test .. error"

Hm. Strange error.
Could you try to perform the test by HostMonitor directly? Will it work?
Do you see any error messages in System Log (file if specified in menu "Options" -> "System Log"). You may access the "System Log" using menu "View" - > "System Log".
Also, could you provide us access to the SNMP agent for testing?

Regards,
Max

[Hirscher]

Ok. What about IP's of the machine, where RMA is running? Have you included it into the SNMP Service's accepts list? The test is performed by RMA, so RMA sends SNMP request from the machine, where it is running.

Yes, I also changed to accept connections from any IPs.

Hm. Strange error. :o
Could you try to perform the test by HostMonitor directly? Will it work?

I tried testing by HM, but I also got the SNMP error. In addition I created a test to monitor the RAID status of an Adaptec RAID controller. It's the same thing, again "cannot connect to SNMP agent" when I click on "GetNext".

Do you see any error messages in System Log (file if specified in menu "Options" -> "System Log"). You may access the "System Log" using menu "View" - > "System Log".

No errors in the Log, just "192.168.250.242: RMA 192.168.250.242: Agent "Juratest" already connected!"

Also, could you provide us access to the SNMP agent for testing?

I'm sorry, but remote access is not possible.

[KS-Soft]

To request SNMP agent HostMonitor uses our own library while MIB Browser uses Windows API. Both application cannot retrieve result, definitely there is something wrong with your SNMP agent. But we cannot say what exactly is wrong.
May be you have installed some SNMP Service extenstions?

Regards
Alex

[KS-Soft Europe]

In addition to Alex's request, I want to ask you to take a look at the Event Log on target system. Do you see any suspicious event records, that are related to SNMP?

Are you able to reach this particular agent using some third party SNMP clients?

Regards,
Max

[Hirscher]

May be you have installed some SNMP Service extenstions?

I checked it and there is actually "WMI SNMP Provider" installed. It shall provide access to dynamic and static SNMP informations. I removed it but that made no difference.

Are you able to reach this particular agent using some third party SNMP clients?

I'm afraid I can't test that because my boss said the server will be sent back to manufacturer today. I think it's best now to go on testing with another one, but I thank you very much for your help and patience.
You do a great job, keep on going.

Regards,
Thomas

[KS-Soft Europe]

I'm afraid I can't test that because my boss said the server will be sent back to manufacturer today.

Right decision. I think, the server was a culprit as well.

but I thank you very much for your help and patience.
You do a great job, keep on going.

You are welcome!
We do our best!

Regards,
Max