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Gagandeep_Mak_3's avatar
Gagandeep_Mak_3
Icon for Nimbostratus rankNimbostratus
Feb 11, 2019

F5 LTM ANY VIP

I have a doubt related to F5 behaviour for a specific scenario.

 

For example: There is a set of servers hosting more than 400 services i.e. different TCP ports. and each service is unique. We are trying to avoid configuring 400+ VIPs on the F5 LTM. As far as monitoring of the services are concerend, server team decided a dedicated TCP port only for monitoring. And rest of the configuration is as below.

 

•Virtual Server configured to listen on any ports, along with an iRule to limit the traffic to specific range of TCP ports •Pool members are also configured to listen on any ports

 

My question is, since pool members are configured to listen on ANY ports, does LB load balancing decision takes the destination TCP port from the client-side connection and uses the same as destination TCP port in server-side connections in this scenario? If not, is there a way to achieve this.

 

application delivery
BIG-IP
LTM

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  • rafaelbn's avatar
    rafaelbn
    Icon for Cirrostratus rankCirrostratus
    Feb 11, 2019

    Hello Gagandeep_Mak!

    It should work like you think it will. The default behavior of the BIG-IP is to translate the destination ports, meaning if your VS listens on port 80 and your pool members listen on port 8080, before sending the traffic to the pool member, the BIG-IP will translate the destination port on the server-side.

    But in your design, since it'll be a "catch all" virtual server with "any" port, BIG-IP should not touch this and just forward as is.

    When you're creating the virtual-server, under advanced configuration, there are two options you could look at: Address translation and port translation.

    Address Translation
Specifies, when checked (enabled), that the system translates the address of the virtual server. When cleared (disabled), specifies that the system uses the address without translation. This option is useful when the system is load balancing devices that have the same IP address. The default is enabled.

Port Translation
Specifies, when checked (enabled), that the system translates the port of the virtual server. When cleared (disabled), specifies that the system uses the port without translation. Turning off port translation for a virtual server is useful if you want to use the virtual server to load balance connections to any service. The default is enabled.

    You could try playing with them if you have any trouble...

    Cheers! Rafael