Technical data

96 ServerIron ADX Advanced Server Load Balancing Guide
53-1002435-03
Sample configurations
2
In this example, suppose you want all traffic to be cached and you want to use the ServerIron ADX’s
default settings. To configure the ServerIron ADX for this example, you define the caches, assign
them to cache groups, and apply an IP policy.
Applying IP policies
For the simple case in which you want to cache everything no matter where it comes from or where
it is going to, use a global policy, such as the following.
ServerIronADX(config)# ip policy 1 cache tcp 80 global
By using a global policy, you can make rule 2 true for all ports. Rule 1 is true by default because all
ports are in cache group 1. Any HTTP traffic flowing across the switch is redirected to the caches.
You can accomplish the same thing with a local policy. With local policies you have to first define
and then apply the policy to the appropriate output ports. In this case, since you want to cache all
traffic, you need to apply the policy to the RAS and BAR ports.
ServerIronADX(config)# ip policy 1 cache tcp 80 local
ServerIronADX(config)# int e 4
ServerIronADX(config-if-4)# ip-policy 1
ServerIronADX(config-if-4)# int e 5
ServerIronADX(config-if-5)# ip-policy 1
ServerIronADX(config-if-5)# int e 6
ServerIronADX(config-if-6)# ip-policy 1
ServerIronADX(config-if-6)# int e 7
ServerIronADX(config-if-7)# ip-policy 1
ServerIronADX(config-if-7)# int e 8
ServerIronADX(config-if-8)# ip-policy 1
NOTE
Note the subtle syntax difference between the commands to create a local policy and apply a policy
to a port. If you leave the dash out of the command, the command does not work.
The local policies make rule 2 true for the BAR and RAS ports. Rule 1 is true by default. Local
policies provide better control at the cost of more configuration steps. If you add a BAR to port 10,
traffic destined for it is not redirected because you have not applied the policy to port 10. With a
global policy, traffic is redirected automatically.
Defining the caches
To make caching work, you need to apply an IP policy and you need to define the caches and assign
them to a cache group. You define cache servers as follows.
ServerIronADX(config)# server cache-name C1 11.11.11.11
ServerIronADX(config)# server cache-name C2 11.11.11.12
ServerIronADX(config)# server cache-name C3 11.11.11.13
The ServerIronADX ARPs for these addresses to determine which ports the caches are on.
Defining the cache groups
A cache group is a collection of ServerIron ADX input ports and cache servers. You can define up to
four cache groups on a ServerIron ADX. Each cache group can have a cache server farm with up to
256 caches. If a cache group has more than one cache server, the ServerIron ADX distributes
traffic among the servers using a hashing algorithm. (Refer to “Increasing the TCS hash bucket
count” on page 54.)