Questions about receiving snmp trap using virtual IP

[Med]

Hi,

If you set the snmp trap destination to the IP added by TCP / IP property instead of the NetXMS server physical IP, the Event Moniter and SNMP Trap Monitor of the NetXMS server are displayed in duplicate.
Is this a specification?
Is there a solution?

OS: Windows 2012
NetXMS: Version 2.2.9

[Constitution]
192.168.0.11: Physical IP
192.168.0.1: added IP
* Set the SNMP trap destination to 192.168.0.1

Best regards,

[Med]

Hi,

The server that runs NetXMS this time uses NIC teaming on Windows to create two interfaces with two NIC as one team.
The settings of the team are as follows.

Teening mode: Switch independent.
Load balancing mode: Address hash
Standby adapter: None (All adapters are active)

In this environment I found that SNMP traps are received in duplicate.
Disabling one side NIC in team properties in this environment will not duplicate.

Is there a solution?

Best regards,

[victor]

Hi,

looks like packets actually got duplicated and sent via both links. You can check that using packet capture tool (Wireshark for example). If this is the vcase then it is network misconfiguration.

Best regards,
Victor

[Med]

Hi,

Thank you for your reply.

Captured using Wireshark, I tried SNMP trap test.
In the previous environment (teaming with two NIC, creating teams with each NIC, creating an interface), we received one, which is not duplicated.
In this environment (two teams using teaming, creating one team to create an interface), we received two cases and were duplicated.
What does "vcase" mean specifically?

Is such an environment assumed for NetXMS?
Is there any example in which there is no duplication in such an environment and it works normally?
Is there a solution?

Best regards,

[victor]

Hi,

if you see two packets in Wireshark then it means packets are actually duplicated. NetXMS server cannot distinguish SNMP trap packets duplicated in transit from two different trap packets, so it process them both. You have to address your network problem - it is definitely network misconfiguration.
"vcase" was a typo - it should be read "case".

Best regards,
Victor

[Med]

Hi,

I'm sorry.
Thank you for pointing out.

Windows teaming + NLB unicast mode was the cause.

Because the NLB's unicast mode shares the same MAC address, packets arrive on each interface, so packets received by each interface were duplicated.

Since the connection destination switch was compatible with IGMP snooping, solving it by enabling IGMP snooping and making NLB from unicast mode to IGMP multicast.

Thanks for the advice.
Thank you very much.