Forum Discussion

alokjhafb_28741's avatar
alokjhafb_28741
Icon for Nimbostratus rankNimbostratus
May 11, 2018

Usefulness of server ip on Big-IP DNS systems

I am trying to understand on a F5 GTM system, what purpose does the server ip fulfill?

 

Say I am setting up a WideIP that's supposed to return the IP of a generic host. How I'd typically go about it is a.) create a "server" object that corresponds to a DataCenter and then b.) configure virtual servers that are part of this server.

 

The Big-IP system requires an IP address for this 'server' object and it doesn't seem to matter what IP you enter - because ultimately - it's the IP of one of the virtual servers that gets returned as the WideIP anyway.

 

I've set up Generic Host servers with made up IPs and it has still worked.

 

  • I guess you ask this question because the server have the same ip as virtual server in your configuration!

     

    But when this product was developed, https server required to add one IP address for each certificate. So one server can host services on other ip addresses.

     

    In such configuration, if you want to add a SNMP monitor, you configure it on only one ip!

     

    But now, with SNI, this requirement disappears! Now, with containers, we can host multiple services on one server listening on different ip addresses...

     

    I understand that 90% of deployments doesn’t require different ip addresses, but this feature is to make other 10% possible!

     

  • Anoop's avatar
    Anoop
    Icon for Nimbostratus rankNimbostratus

    All of the resources on a network are associated with a data center. BIG-IP DNS(formerly GTM) consolidates the paths and metrics data collected from the servers, virtual servers, and links in the data center. BIG-IP DNS uses that data to conduct load balancing and route client requests to the best-performing resource, based on a variety of factors.

     

    A server defines a physical system on the network. Servers contain the virtual servers that are the ultimate destinations of DNS name resolution requests. A virtual server is a specific IP address and port number that points to a resource on the network. In the case of host servers, this IP address and port number likely point to the resource itself.

     

    Here is the following order of creation in generalization.

     

    Data Center --> Servers --> Virtual Servers --> pool --> Topology (optional) ---> WideIP