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Kevin_Tang's avatar
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Jan 12, 2021

multiple floating self IPs for the same vlan and within the same traffic group


Is that a valid config to give more than 1 floating self IPs for the same vlan in F5 LTM? Also with the same traffic group setting.

I saw on F5 LTM cluster configured this way and looks like still working.

for example: both floating self IPs are and, they have the same MAC address. Back end servers and have 2 NICs, they are not using or as default gateway. The other NIC IPs are and, the servers are using as default gateway.


The traffic can reach to server and via both floating self IPs and, but and have the same MAC address. I am not sure how the F5 LTM Layer2 forwarding table works.


Anyone has this type of setup in F5 LTM?




1 Reply

  • Having two floating IP in the same VLAN is a working scenario and I am not aware of any problem it can cause, however since you are using SNAT and as per K7820:


    If multiple floating self IP addresses are configured on the VLAN, the BIG-IP system translates the address of client connections by alternating through a pool of all floating self IPs on the VLAN.


    Regarding MAC addresses, the BIG-IP will advertise the physical interface MAC of the active node for arp reponses for and unless you configure MAC Masquerade in the traffic group.