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Johannes_106389's avatar
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Jun 09, 2012

LTM VLAN-setup and tagging




We have a couple of LTMs and when we setup a new environment we do this:




VLAN 10 - Transport VLAN between our external firewall and the LTM, this is where we setup the VIP.


VLAN 20 - VLAN where the loadbalanced servers are located.












SW ==== LTM (vlan 10 tagged on interface 1, vlan 20 tagged on interface 2)











| | |








Is this setup wrong? Should we tag both VLAN10 and VLAN20 on the same interface (interface1)?






2 Replies

  • What is the best practice, is it even neccesary to use a separate VLAN for the "TRANSPORT"-traffic?



  • Johannes -



    Untagged = 1 VLAN per interface


    Tagged = 802.1q tagging (multiple VLANS on an interface), or a TRUNKED interface in Cisco terms.



    There isn't really a right or wrong. The interfaces work either way. Personally, I like to have all my VLANS in one group running to a Trunk (f5 terminology) on the LTM (multiple interfaces bonded together using LACP) and to different back end switches if your environment can support it. That way if one interface goes down, you don't lose the VLANs and cause a fail-over on the LTM if you are set up that way.



    Hope this helps.