Forum Discussion

DMB_19518

Altocumulus

Feb 02, 2017

UDP Virtual server (port 162) not working

Dear community,

I have set up a UDP standard Virtual Server with two members, listening to port UDP 162. The purpose of this VS is to balance SNMP traps to the active pool member. The pool has been configured with priorities, meaning that the VS will send traps to one pool member, and when this member is down, the VS will use the other.

The VS is not working. Traps sent to the VS are not balanced over the member(s). However, the members are listening and a direct trap sent to the member is processed correctly.

Is anybody aware of a bug in the software?

Note: there is a related question already in devcentral here that seems to point to a bug, as on that thread, the way to make the UDP VS work was by configuring the VS to listen to all ports instead of an specific one. If possible i would like to avoid that.

Thanks a lot in advance!

application delivery

LTM

DMB_19518
Mar 08, 2017
To finish this topic, there was nothing wrong with the VS definition nor in the software release. The problem was in a wrong pool member health monitor configuration, that was causing the VS to become not available.

Thanks to all replies.

PS - lesson learned: an udp health monitor was not enough to monitor the pool for this specific case, as this monitor is always "green" even if port 162 is not listening in the pool member. This was corrected by adding a second monitor and hence, truly determining the status of the pool member.

KeesvandenBos
MVP
Feb 02, 2017
Hi,

Could you post a tmsh list ltm virtual

Cheers,

Kees

DMB_19518

Altocumulus

Feb 02, 2017

Hi Kees, thanks for replying. Yes, here it goes:

ltm virtual OAM_INT_CN_MON_ALARM_INT_VS_162 {
    destination 192.168.30.242:snmptrap
    ip-protocol udp
    mask 255.255.255.255
    pool OAM_INT_CN_MON_ALARM_INT_Pool
    profiles {
        udp { }
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vlans {
        VLAN_333_OAM_INT
    }
    vlans-enabled
    vs-index 203
}

Also some info on the SW version:

Main Package
  Product  BIG-IP
  Version  11.4.1
  Build    711.0
  Edition  Hotfix HF11
  Date     Tue Aug 30 12:18:51 PDT 2016

KeesvandenBos
MVP
Feb 02, 2017
What are the ip addresses of the pool members?

And if you change the virtual server port to any, does it work?

Cheers,

Kees
Vijay_E
Cirrus
Feb 04, 2017
Are you saying that the traffic is being sent to the pool members but it is not evenly distributed across multiple pool members ?
DMB_19518
Altocumulus
Feb 06, 2017
I am now trying to rule out the pool configuration. I'll update the status once i have the results.

Thanks!
DMB_19518
Altocumulus
Mar 08, 2017
To finish this topic, there was nothing wrong with the VS definition nor in the software release. The problem was in a wrong pool member health monitor configuration, that was causing the VS to become not available.

Thanks to all replies.

PS - lesson learned: an udp health monitor was not enough to monitor the pool for this specific case, as this monitor is always "green" even if port 162 is not listening in the pool member. This was corrected by adding a second monitor and hence, truly determining the status of the pool member.
DMB_19518
Altocumulus
Mar 08, 2017
The problem was in the health monitor configuration. I posted the final answer.