Hi,

I am trying to setup SNMP traffic for my remote site via VSAT link.
I had simulated the SNMP traffic in shore network and found no problem on the device UID.
I also verified with provider there is no port blocking from their side.
The only difference I can from setup was the latency to remote which is around 800ms average.

Can you help to verify if this was related to latency or something else, will the SNMP timeout probably can resolved. Tried to modify the timeout but still failed.

Article Comments

To troubleshoot the SNMP communication You may want to download our latest SNMP Tester, ideally run it on the PRTG Host (or host of the Remote Probe), and perform the "Read Device Uptime" test against the target device, it will allow you to easily test different credential combinations to confirm the communication.

You can also increase the timeout in the SNMP Tester Tool to see if it makes a difference.

Best Regards,
Luciano Lingnau [Paessler Support]


May, 2018 - Permalink

Hi Support,

I was able to simulate and test SNMP using SNMP tester:

As per below test:

  1. st test to Public IP remote site where latency over 600ms, shows no response
  2. nd test to my Public domain with normal internet latency and it is working fine, therefore port forwarding from my FW is working fine.
  3. rd test to Private IP remote with VPN tunnel and latency over 600ms, it is working fine, therefore seems latency is not the problem.

I had check with the remote site service provider and they confirmed there was no port blocking from their side. Any idea where could be the problem? Thank you

----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: PTEL-PC Interface: (192.168.56.1, 192.168.0.62)
5/11/2018 10:50:15 AM (1 ms) : Device: XXXXXXXXXXX
5/11/2018 10:50:15 AM (2 ms) : SNMP V2c
5/11/2018 10:50:15 AM (2 ms) : Uptime
5/11/2018 10:51:15 AM (60015 ms) : SNMP Datatype: ASN_PRIMITIVE
5/11/2018 10:51:15 AM (60016 ms) : -------
5/11/2018 10:51:15 AM (60017 ms) : DISMAN-EVENT-MIB::sysUpTimeInstance = No response (check: firewalls, routing, snmp settings of device, IPs, SNMP version, community, passwords etc) (SNMP error # -2003) ( 0 seconds )
5/11/2018 10:52:15 AM (120028 ms) : SNMP Datatype: ASN_PRIMITIVE
5/11/2018 10:52:15 AM (120030 ms) : HOST-RESOURCES-MIB::hrSystemUptime.0 = No response (check: firewalls, routing, snmp settings of device, IPs, SNMP version, community, passwords etc) (SNMP error # -2003) ( 0 seconds )
5/11/2018 10:52:15 AM (120031 ms) : Done


----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: PTEL-PC Interface: (192.168.56.1, 192.168.0.62)
5/11/2018 11:06:24 AM (4 ms) : Device: YYYYYYYY
5/11/2018 11:06:24 AM (5 ms) : SNMP V2c
5/11/2018 11:06:24 AM (7 ms) : Uptime
5/11/2018 11:06:24 AM (22 ms) : SNMP Datatype: ASN_TIMETICKS
5/11/2018 11:06:24 AM (24 ms) : -------
5/11/2018 11:06:24 AM (26 ms) : DISMAN-EVENT-MIB::sysUpTimeInstance = 6957000 ( 19 hours 19 minutes )
5/11/2018 11:06:24 AM (41 ms) : SNMP Datatype: SNMP_EXCEPTION_NOSUCHINSTANCE
5/11/2018 11:06:24 AM (43 ms) : HOST-RESOURCES-MIB::hrSystemUptime.0 = No such instance (SNMP error # 223) ( 0 seconds )
5/11/2018 11:06:24 AM (45 ms) : Done


----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: PTEL-PC Interface: (192.168.56.1, 192.168.0.62)
5/11/2018 11:06:35 AM (5 ms) : Device: ZZZZZZZZZZZ
5/11/2018 11:06:35 AM (8 ms) : SNMP V2c
5/11/2018 11:06:35 AM (11 ms) : Uptime
5/11/2018 11:06:36 AM (1250 ms) : SNMP Datatype: ASN_TIMETICKS
5/11/2018 11:06:36 AM (1251 ms) : -------
5/11/2018 11:06:36 AM (1253 ms) : DISMAN-EVENT-MIB::sysUpTimeInstance = 243700 ( 40 minutes 37 seconds )
5/11/2018 11:06:38 AM (2580 ms) : SNMP Datatype: SNMP_EXCEPTION_NOSUCHINSTANCE
5/11/2018 11:06:38 AM (2582 ms) : HOST-RESOURCES-MIB::hrSystemUptime.0 = No such instance (SNMP error # 223) ( 0 seconds )
5/11/2018 11:06:38 AM (2583 ms) : Done

May, 2018 - Permalink

Hello there,
than you for your reply and tests.

Based on the timings in your log, you've used a timeout of 60 seconds, but still got no response, correct?

Essentially, the latency not be the major issue here. The second issue could be QOS on the intermediate devices or even the UDP nature of SNMP. Please keep in mind, that as SNMP is UDP based there is no guarantee that it will indeed arrive at the target device. Essentially, there may be equipment along the route to this destination that will silently drop the SNMP packets in favor of forwarding "more important" traffic.

Performing a wireshark capture on UDP 161 and repeating the 1st test may show you more details. For example, if you're getting an ICMP reply with an error code for the SNMP query.

Best Regards,
Luciano Lingnau [Paessler Support]


May, 2018 - Permalink

Hi Support,

Thank you for your response. Will try to further check on it. Thanks


May, 2018 - Permalink