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Ken_B_50116's avatar
Ken_B_50116
Icon for Cirrostratus rankCirrostratus
Dec 08, 2014

Why do I have to specify "SMB/CIFS Server" in SMB health monitor?

I am creating a new SMB health monitor in BigIP LTM 11.4.1 HF1. One of the required fields is "SMB/CIFS Server". This document...

 

https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-11-2-0/3.html

 

..says this:

 

"SMB/CIFS Server - Specifies the NetBIOS server name of the SMB/CIFS server for which the monitor checks for availability. You must specify a server for this monitor to function."

 

Does this not completely defeat the point of using a load balancer in the first place? If the monitor relies on a single server to be valid, then this is a gigantic single point of failure.

 

Should the "SMB/CIFS Server" field not be the same as the pool members that the monitor is checking the health of? How can the health of a pool be tied to a single server? What's the point?

 

Clearly I am totally missing something here. Please help me learn.

 

Thanks!

 

application delivery
availability
design
health monitor
LTM
microsoft

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  • mimlo_61970's avatar
    mimlo_61970
    Icon for Cumulonimbus rankCumulonimbus
    Dec 08, 2014

    Probably has something to do with needing the netbios name, which is not necessarily part of the pool. I can't disagree though that it seems counter to what a pool monitor should do. Maybe setup one for each member and apply it as a node monitor instead of a pool monitor.

     

  • Ken_B_50116's avatar
    Ken_B_50116
    Icon for Cirrostratus rankCirrostratus
    Dec 08, 2014

    That is a great suggestion, however some of my monitors were not valid for nodes. Many monitors did not appear in the drop-down list in the GUI, and the CLI gave me this error when trying to add my SMB node-specific monitor to a node:

    01070588:7: The requested monitor rule (/Common/AgfaCVwebSMB_VMWEBHLHHE1) can only be applied to pool members.

    Googling the 01070588:7 error turns up this post:

    https://devcentral.f5.com/questions/the-requested-monitor-rule-xxxx-can-only-be-applied-to-pool-members

    This lead me to discover that the "Alias Address" field of the node has to be populated with something other than the wildcard (and probably the port number field too.) I set those in the monitor and now it appears as a valid monitor for a node.

    I am continuing to test.

    • Christopher_Noy's avatar
      Christopher_Noy
      Icon for Nimbostratus rankNimbostratus
      Dec 09, 2016

      Did you ever get this to work? I am in a similar situation; I don't see how specifying the SMB name for a single server makes this a useful monitor.