Application Level Gateway

An Application-Level Gateway (ALG) is a firewall proxy that provides network security. It filters incoming node traffic to certain specifications which mean that only transmitted network application data is filtered.

LSN provides Application Level Gateway (ALG) support for the following protocols:

• Domain Name Server (DNS)
• H323
• Media Gateway Control Protocol (MGCP)
• File Transfer Protocol (FTP)
• Trivial File Transfer Protocol (TFTP)
• Session Initiation Protocol (SIP)
• Real Time Streaming Protocol (RTSP)
• Point-to-Point Tunneling Protocol (PPTP) Generic Routing Encapsulation (GRE)
• IPsec Encapsulating Security Payload (ESP)

By default, ALG support for DNS and FTP is enabled, but ALG support for the other protocols is disabled. This section allows you to disable or enable Application Level Gateway (ALG) support for LSN.

The ALG page allows you to perform the following:

• Create
• Edit

View an ALG List

To view ALG list, navigate to CGN Technology > LSN (NAT 44) > ALG.

The field description for view, create, and edit are the same. For the field description, see Configure an ALG.

Edit an ALG

To edit an ALG:

1. Navigate to CGN Technology > LSN (NAT 44) > ALG
2. Select an ALG that you want to edit, click the Kebab menu, and click Edit.
3. On the Edit ALG page, update the required details and click Update.
   The update confirmation message is displayed.