Cache Redirect
FortiWAN is capable of working with external cache servers. When a user requests a page from a web server on the internet, FortiWAN will redirect the request to the cache server. If the requested web page is already on the cache server, it will return the page to the user, thus saving time on data retrieval. Cache servers are configured here. However, cache servers have to support caching in transparent mode. Note: Cache Server can be in DMZ.
FortiWAN provides log mechanisms on events refer to the Connection Limit service, see “Log”.
Cache Group
The first table configures cache server groups. Multiple groups can have different sets of rules which are then created on the second table. In addition, the number of cache servers is not limited to one. Therefore it is possible to have multiple cache servers with different weights in the cache server group.
| Group Name | Assign a name for this cache server group. |
| IP | The IPv4 address of the cache server. |
| Port | The port number of the cache server. |
| Weight | The weight for redirecting the requests to this cache server. A higher value means a greater the chance. |
Cache Redirect
| Associated WAN | Select WAN link associated with the cache server. Cache redirect works only when both the selected WAN link and the cache server are available. Selecting “NO” means cache redirect is not associated with WAN links. No matter a WAN link is available or not, cache redirect can work if the cache server is available. |
Redirect Rule
| Source | The source where the request originates and it will be redirected to the cache server. Specify the IP(s) when selecting “IPv4 Address”, “IPv4 Range” and/or IPv4 subnet (See “Using the web UI”). |
| Destination | The destination where the request will be sent and it will be redirect to the cache server. Specify the IP(s) when selecting “IPv4 Address”, “IPv4 Range” and/or IPv4 subnet (See “Using the web UI”). |
| Port | The service port number and it will be redirected to the cache server. |
| Group | Select “NO REDIRECT” for requests not to be directed. Or assign pre-existing group to redirect the requests. |
| L | Enable logging or not: If the box is checked, the logging will be enabled. Whenever the rule is matched, the system will write the event to the log file. |
Redirect rules can be established to match requests that will be redirected to the specific cache server group.
Cache Redirect
Example 1 The Requested Web Page is NOT on the Cache Server
When FortiWAN receives a request from a client, the request will be redirected to the cache server. The cache server will determine if the data requested already exists or not. If not, then the request will be performed on behalf of the client with the data returned from the web server to the client.
Internal DNS
Example 2 The Requested Web Page is on the Cache Server
When FortiWAN receives a request from a client, the request will be redirected to the cache server. In this case, the data requested already exists on the cache server. Therefore it will return the data requested to the client without passing the actual request to the internet.