Technical data

46 ServerIron ADX Advanced Server Load Balancing Guide
53-1002435-01
Other TCS options
2
Removing an interface from a cache group
You can remove an interface from a cache group to assign it to another cache group or to bias its
traffic away from cache servers entirely.
ServerIronADX(config)# interface ethernet 3
ServerIronADX(config-if-3)# no cache-group 1
Syntax: [no] cache-group <group-#>
Assigning an interface to a cache group
To assign an interface to cache group, enter the following command.
ServerIronADX(config)# interface ethernet 3
ServerIronADX(config-if-3)# cache-group 1
NOTE
You must use cache-group 1 to remove no cache-group command.
NOTE
You must create the cache group before you can assign an interface to the group.
Cache Route Optimization
Typically the ServerIron ADX sits between a border access router (BAR) and a remote access server
(RAS) where the BAR connects to the Internet/Intranet. The RAS forwards the client HTTP traffic to
the ServerIron ADX, which re-directs the traffic to the cache servers. When a border router is
configured as the default router for the cache servers, all traffic sent towards the browsing clients
behind the RAS must first go to the BAR.
At Layer 3, the cache server sends its response to the IP address of the client (or to the ServerIron
ADX if source NAT is enabled on the ServerIron ADX). However, at Layer 2, the cache server sends
its response to the MAC address of its default gateway. In configurations where the default
gateway is the BAR, this traffic pattern can cause significant (and unnecessary) BAR performance
degradation and poor response time as perceived by the clients.
The Cache Route Optimization (CRO) feature sends traffic from a cache server toward the RAS.
When you enable the feature, the ServerIron ADX uses information in its Layer 4 session table and
its traffic pattern recognition capabilities to redirect the traffic directly toward the clients instead of
sending the traffic needlessly to the BAR.
CRO is disabled by default.
Enabling Cache Router Optimization
Cache Route Optimization (CRO) is useful for situations in which a cache server’s default gateway is
the Border Access Router (BAR) that goes to the Internet, instead of the remote access server (RAS)
that goes to the HTTP clients.
When you enable CRO, the ServerIron ADX intelligently sends cache responses directly to the RAS
at Layer 2 instead of sending them to the BAR for switching back through the ServerIron to the RAS.
CRO is enabled on a ServerIron ADX as shown.
ServerIronADX(config)#server cache-router-offload