From HowToGeek

Application Layer Gateway Service (alg.exe) Application Gateway Program that runs on a firewall between two networks.

Contents 1 Overview 2 System Requirements 3 Related How-To Geek Articles 4 See Also 5 References

Overview

ALG.EXE is a sub component of the Internet Connection Sharing (ICS) and Internet Connection Firewall (ICF) services in Windows. This allows third party application protocols to work behind the firewall. ALG is installed during normal Operating System installation. It listens to (FTP) File Transfer Protocol requests on TCP Port 21

In Windows it is set to Manual by default. This service should not be disabled.

System Requirements

Windows XP, Server 2003, Vista

Related How-To Geek Articles

None at this time

See Also

Internet Connection Sharing (ICS)

Internet Connection Firewall (ICF)

References

• Microsoft TechNet

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