The ARM

The Content Gateway ARM inspects incoming packets before the IP layer sees them and readdresses the packets to Content Gateway for processing.

The ARM can make two changes to an incoming packet's address. It can change its destination IP address and its destination port. For example, the destination IP address of an HTTP packet is readdressed to the IP address of the proxy and the destination HTTP port is readdressed to the Content Gateway HTTP proxy port (usually port 8080).

On the way back to the client, the ARM changes the source IP address to the origin server IP address and the source port to the origin server port.

The ARM component consists of several files and a kernel module, which are installed during product installation. The installation program also creates redirection rules to readdress packets using the IP address of the proxy machine and default port assignments. The ARM is always active.

For the proxy to serve HTTP, HTTPS, FTP, or DNS requests transparently, you must check the redirection rules in the ipnat.conf file and edit them if necessary. If you are using WCCP for transparent interception, there must be a redirection rule for every port in every active service group. Rules for standard ports are included by default. To view and work with ARM redirection rules, follow the these steps.

Log on to the Content Gateway manager and go to Configure > Networking > ARM > General.

The Network Address Translation (NAT) section displays the redirection rules in the ipnat.conf file. Check the redirection rules and make any needed changes.

To change a redirection rule, click Edit File to open the configuration file editor for the ipnat.conf file.

Select the rule you want to edit and modify the appropriate fields. Click Set and then click Apply to apply your changes. Click Close to exit the configuration file editor.

All fields are described in ARM.

Click Restart on Configure > My Proxy > Basic > General.