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awan_m's avatar
Icon for Cirrostratus rankCirrostratus
Nov 15, 2023

Multiple VIPS on GCP single nic F5

HI all - i have deployed a Sigle Nic F5 in GCP 

it has a primary internal IP - 10.10.10.x - and a External IP - - that has a DNS record 

Question - how do i create a Second Vip for a second DNS record .

example - i get a dns - IP = - 

How would i create a second Virtual server - as i cannot allocate a second IP to the F5 . Please Help 


7 Replies

    • awan_m's avatar
      Icon for Cirrostratus rankCirrostratus

      Thanks for the response - but my question is regarding th ecapability - 

      meaning - is it possible to have multiple IPs on the F5 in GCP - 

      • AdirZe's avatar
        Icon for Altocumulus rankAltocumulus

        You can assign additional alias IPs /32 or subnet to the Single Nic in GCP, and then create virtual servers that listen for these IPs on the F5 Device.


        Best Regards

  • Good point, If no external firewall is found in front of the F5,  You can use instead of the Alias IP  - a forwarding rule.

    The forwarding rule will listen for the second public IP and point the traffic to the F5 Compute engine (VM). On the F5 Device you should create a second virtual server with the destnation ip of the GCP public IP address. 

    Let me know if it works for you.

    Best Regards, 

  • btw if the traffic is http/s, you can serve multiple hostnames using LTM virtual server.
    you can use traffic policy/irules to read Host request header and route to to specific pools.
    it's usually called virtual host method in webservers.

  • HI,

    So to me this is a question of network ranges.
    So you have a external IP and you want to have a second IP so say, now if these are just /32 address these will need to be on different interfaces on your external firewall..

    Or these will need to be in same wider subnet so /24 or /27 or something like that. So one physical interface can have 2 IP's with the same gateway,
    Now with that in mind, on the f5 the same will need to our if your first VIP is say, it should be in the same subnet of at least a self-ip and its gateway so should be in a /29 or higher network, which would give you a second IP say so this address will actually be to use for your second VIP make the network address wider on your external edge and you can have more VIP's / IP!. If you add a cluster you'll need an additional Self IP for each NIG-IP in that cluster.

    Once you have the suitable network ranges for this to work, you then just need to map your NAT rules from external to internal and you should be ready to rock!

    If you can only have one internal IP, you could always have to exteranl IP's say on port 443.
    And use the external firewall to NAT them to different ports.
    So something like
    ExtIP01:443  => IntIP01:3001
    ExtIP02:443  =>  IntIP01:3002

    Which dependant on your constraints in your system may give you a little more flexiablity.