Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

basic question


We are buying ACEs. We're having an outside contractor do the initial implementation, but I'll be maintaining after they leave, so I'm reading to get conversant with the technology.

I've come across config instructions that seem to mean the VIP of a server farm is the IP address of the interface for the VLAN the real servers are in.

Is that true?

Later... In the same doc (full doc details below...), near the end of "Configuring Basic...", in the Verifying the VIP Load-Balancing section, it says "You can also verify access to the real servers by using a Telnet session to connect to the VIP address". But the address they use to demonstrate ( was not configured on anything in this doc. And it certainly isn't the IP address of the interface for the VLAN the real servers are in... I think I'm confused...

Wait - Steps 5 & 6, in Configure the VIP Traffic Policy creates a class-map, then does "match virtual-address any". Is THAT where the VIP gets created?

(My first instinct, before any reading, was that you'd somehow assign an IP address to the server farm itself. But this doc doesn't say any such thing.)

Also - It seems to me this means that implementing smaller server farms (one farm for 5 web servers for instance, another for 5 ftp servers...) requires subnetting if you don't want to waste huge piles of address space. True?

(I know this is very basic stuff - any and all guidance/confirmation/correction most sincerely appreciated...)

The doc I'm referring to is Cisco Applicaton Control Engine Module Getting Started Guide. (

chapter Configuring the ACE and Performing Basic VIP Load Balancing, section Configuring a Server Farm, starting with Step 9.


Re: basic question

The VIP has nothing to do with how the real servers are subnetted. The VIP is just the IP address clients connect to, and serverfarms are simply a list of real servers that are assigned to service a VIP. The VIP does not need to be part of same subnet as the real servers.

In your example you can have 5 web servers and 5 ftp servers all on the same subnet if you wish:

Web VIP =

Web Real webserver1 =

Web Real webserver2 =

Serverfarm Web

webserver1 inservice

webserver2 inservice


FTP Real ftpserver1 =

FTP Real ftpserver2 =

Serverfarm FTP

ftpserver1 inservice

ftpserver2 inservice



CreatePlease to create content