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Milan_61890's avatar
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Oct 14, 2013

2 LACP paths to 2 switches without spanning-tree

Is the following setup possible?: A BIG-IP appliance should be redundantly connected to two switches without using spanning-tree. Each switch should be connected to the BIG-IP by two aggregated interfaces/ports (802.3ad). One of the two aggregated paths (to one of the switches) should be active, the other (to the other switch) passive. How should it be set up? Thank you so much! Milan


3 Replies

  • Ah, I thought you meant on the F5. That being the case, you can do this but you'd need to ensure the connections between the F5 and the switches are loop free (no link between the switches for any VLAN the F5 is in) or layer three (routed). In either case, all the links will be active at once but with the layer three method how you setup your routing will influence which links are actively used to pass traffic.


  • I have a similar scenario. A cluster with 2 F5 nodes, each node has a LACP 2 x 10G and each fiber connects to a different Cisco Nexus switch. Last week, we connected an inline IPS between one of the F5 appliance and the two switches. After some minutes, we started seeing applications(some being served by this F5 cluster and some others not) and vpn's not responding or doing so intermittently. The network got stable after disconnecting the IPS appliance. Any idea what could be causing this behavior?