HP StorageWorks Enterprise File Services WAN Accelerator 3.0.4 deployment guide (AG421-96001, March 2007)

HP STORAGEWORKS ENTERPRISE FILE SERVICES WAN ACCELERATOR DEPLOYMENT GUIDE 73
7 - WCCP DEPLOYMENTS
The following steps describe how WCCP works with the HP EFS WAN Accelerator:
1. Routers and HP EFS WAN Accelerators are added to the same service group.
2. HP EFS WAN Accelerators announce themselves to the routers.
3. Routers send back the state of the service group.
4. One HP EFS WAN Accelerator takes a leadership role and tells the routers how to
redirect traffic among the HP EFS WAN Accelerators in the service group.
The HP EFS WAN Accelerators use the following methods to communicate with
routers:
 Unicast (User Datagram Protocol Packets). The HP EFS WAN Accelerator is
configured with the IP address of each router. If additional routers are added to
the service group, they must be added on each HP EFS WAN Accelerator.
 Multicast. The HP EFS WAN Accelerator is configured with a multicast group.
If additional routers are added, you do not need to add or change configuration
settings on the HP EFS WAN Accelerators.
All TCP traffic is redirected by default. You can configure specific source or
destination ports to be redirected. For detailed information, see “TCP Port
Redirection” on page 87.
For other types of redirection filtering such as the IP address, you configure ACLs on
the routers and add it to the service group. For detailed information, see “Specific
Traffic Redirection” on page 87.
Traffic is redirected using one of the following schemes:
 gre (Generic Routing Encapsulation). Each data packet is encapsulated in a
GRE packet with the HP EFS WAN Accelerator IP address configured as the
destination. This scheme is applicable to any network.
 l2 (Layer-2). Each packet MAC address is rewritten with an HP EFS WAN
Accelerator MAC address. This scheme is possible only if the HP EFS WAN
Accelerator is connected to a router at Layer-2.
 either. The either value uses l2 (Layer-2) first—if Layer-2 is not supported, gre
is used.
You can load-balance using WCCP. Traffic is redirected based on a hashing scheme
and the weight of the HP EFS WAN Accelerators. You can hash on a combination of
the source IP address, destination IP address, source port, or destination port. The
default weight is based on the HP EFS WAN Accelerator model number. (The weight
is heavier for models that support more connections.) You can modify the default
weight. For detailed information, see “Load Balancing” on page 87.