How does wccp works

Here is an excerpt from Cisco:. Choosing a mask that works best with your environment allows you to have better control of how traffic will be distributed between proxies and makes it much more deterministic so if for example you choose 0x1 as your mask you know that any clients with even last octets are going through one proxy and all the odd last octets are going through another proxy. You are commenting using your WordPress. You are commenting using your Google account.

You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. A mask of 0x , we end up with two buckets again, with even third octets going to one proxy and odd numbered third octets going to a different proxy Cisco has a good writeup on their recommendations on the WCCP mask values for different environments available on this page.

For data center deployments, the goal is to load balance the branch sites into the data center rather than clients or hosts. Copyright Forcepoint LLC. All rights reserved. Important The network clients, Content Gateway proxy servers, and destination Web servers default gateway must reside on separate subnets. Install and configure your WCCP v2 devices. Configure the service groups.

Configure password security, if needed. Configure multicast communication, if needed. Define matching service groups. When the cache engine retrieves the requested information, it forwards it to the requesting client and caches it to fulfill future requests, thus maximizing download performance and substantially reducing transmission costs. In this scenario, this router is the device that performs all the IP packet redirection. Content is not duplicated on the cache engines.

The benefit of using multiple caches is that you can scale a caching solution by clustering multiple physical caches to appear as one logical cache.

Multiple routers can use WCCPv2 to service a cache cluster. This is in contrast to WCCPv1, in which only one router could redirect content requests to a cluster. Using WCCPv1, the cache engines were configured with the address of the single router. WCCPv2 requires that each cache engine be aware of all the routers in the service group. This method is negotiated between the router and the WAAS device.

Packet redirection is handled entirely by the router software. The WAAS device de-encapsulates the datagram, evaluates the payload using the static bypass rules and WAAS Policy specification, and either accepts or rejects the packet.

If the packet is rejected because of a static bypass rule, it is re-encapsulated and returned to the router. The router understands that the WAE is not interested in this connection and forwards the packet to its original destination.

All other packets, pass-through or optimized, are returned to the router using the configured packet egress method. The rest of the traffic may be handled by the router hardware on supported routers and switches making L2 redirection more efficient than Layer 3 GRE. This method is negotiated between a router and all cache engines on a per Service Group basis. This requires that changes to the WCCP configuration be made individually on each node.

If after being disabled this option is enabled, the configuration on the node on which the option is enabled is used to initially synchronize the cluster. List order has no meaning; therefore, the up and down arrows can be ignored. Adds a new service group definition. After Add is clicked, the new definition is displayed in the box at the top of the page. Accepts modifications to the selected service group definition, displaying the new values in the box at the top of the page.

Service Group Information. If you change this option, you must restart Content Gateway. Specifies a unique service group name. This is as an aid to administration. Specifies a service group ID between This ID must also be configured on the router s.

If the specified number is already in use, an error is displayed when Add or Set is clicked. Specifies the Ethernet interface on this Content Gateway host system to use with this service group. On a V appliance, eth0 is bound to P1 and eth1 is bound to P2.

Mode Negotiation. These settings are required and cannot be changed. Specifies the preferred encapsulation method used by the WCCP router to transmit intercepted traffic to the proxy. If the router supports GRE and L2, the method specified here is used. Important: GRE and Multicast are incompatible. Important: If you change the forward or return method configuration while there is an active connection with the WCCP device, in order to re-negotiated the method you must force the current connection to terminate.

Typically, this means turning off the service group on the WCCP device for 60 seconds. See the documentation for your WCCP device. Specifies the preferred packet encapsulation method used to return intercepted traffic to the WCCP router.