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balleste_156980's avatar
balleste_156980
Icon for Nimbostratus rankNimbostratus
Nov 20, 2016

Server node load balanced IP address and management IP address are different.

Not sure if this is possible, but wanted to reach out to the greater community for help. I have a bunch of email servers that have two interfaces; one for server management, and one for SMTP. I have a VIP that load balances traffic for the email servers using the SMTP interface and a monitor check using the SMTP monitor.

 

I wanted to add an additional monitor using the SNMP DCA base monitor feature, but the only issue is that the only way to for the F5 to get the data is using the management interface.

 

For example:

 

VIP: 192.168.2.250 Port: 25 Monitor: SMTP

 

Pool: Server A: Eth1 (smtp): 192.168.2.1 Server B: Eth1 (smtp): 192.168.2.2

 

I wanted to add a new monitor using SNMP DCA Base but the issue is that the only way to get the data is to query the management interface. For Server A, this would be Eth0 (management): 192.168.1.1.

 

Any ideas?

 

application delivery
BIG-IP
devops
LTM

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  • balleste_156980's avatar
    balleste_156980
    Icon for Nimbostratus rankNimbostratus
    Nov 20, 2016

    Or would a better solution be to use an iRule to automatically remove the email server from rotation if the SNMP DCA Base check fails? And if so, any ideas on an irule?

     

  • boneyard's avatar
    boneyard
    Icon for MVP rankMVP
    Nov 20, 2016

    doesn't seem like something for an iRule. iRule act mainly on traffic, not on health monitors.

     

    you can just make a health monitor with a specific IP hardcoded in it. add that health monitor to your pool and eventough the pool as the SMTP IP it will monitor the mgmt IP.

     

    this approach might get a bit annoying if you have 100s of servers that require this, as you need one per server.

     

    come to think of it, you might have issues already as you can't really explain that one mgmt IP is connect to one SMTP IP ... hmmm, have a look at the idea and if it doesn't work just let us known and perhaps another suggestion can help you.

     

  • KeesvandenBos's avatar
    KeesvandenBos
    Icon for MVP rankMVP
    Nov 21, 2016

    Balleste,

     

    You can create a snmp_dca monitor with an alias address (mgmt address) per smtp server and attach it to the corresponding node.

     

    Cheers,

     

    Kees

     

  • boneyard's avatar
    boneyard
    Icon for MVP rankMVP
    Nov 25, 2016

    never knew that, never used the SNMP monitor either so that makes sense.

     

    then if you really want this an external monitor in which you do the SNMP read in a script is the only other option.