Command Reference Guide Global Configuration Mode Command Set
61200990L1-35E Copyright © 2005 ADTRAN 371

ip firewall alg [ftp | h323 | pptp]

Use the ip firewall alg command to enable the application-level gateway (ALG) for a particular
application. Use the no form of this command to disable ALG for the application.
Syntax Description
ftp Enables the FTP ALG.
h323 Enables the H323 ALG.
pptp Enables the PPTP ALG.
Default Values
By default, the ALG for FTP, H323, and PPTP are enabled.
Applicable Platforms
This command applies to the NetVanta 300, 1000R, 3000, 4000, and 5000 and Total Access 900 Series
units.
Command History
Release 8.1 Command was introduced.
Release 10.1 H323 was added.
Functional Notes
Enabling the Application Layer Gate way (ALG) for a specific protocol gives the firewa ll addi tiona l
information about that complex protocol and causes the firewall to perform additional processing for
packets of that protocol. When the ALG is disabled, the firewall treats the complex protocol as any other
simple protocol. The firewall needs no special knowledge to work well with simple protocols.
Usage Examples
The following example disables ALG for FTP:
(config)#no ip firewall alg ftp
Disabling the IP firewall ALG may cause the firewall to block some of the traffic for
the specified protocol.