[ Contents] [ Prev] [ Next] [ Index] [ Report an Error]

Blocking Packets with Either a Loose or Strict Source Route Option Set

Checking for SYN flags can prevent attackers from using IP source route options to hide their true address and access restricted areas of a network by specifying a different path. TCP SYN checking is on by default.

Before You Begin
For background information, read Understanding Attacker Evasion Techniques.

You can use either J-Web or the CLI configuration editor to block packets with either a loose or strict source route option set. The specified security zone is the one from which the packets originated.

This topic covers:

J-Web Configuration

To configure screens:

Select CLI Tools>Point and Click CLI.
Next to Security, click Configure or Edit.
Next to Screen, click Configure.
Next to Ids option, click Add new entry.
In the Name box, type ip-filter-src.
Next to Ip, click Configure.
Next to Source route option , select the check box and click OK.
To save and commit the configuration, click Commit.

To configure zones:

Select CLI Tools>Point and Click CLI.
Next to Security, click Edit.
Next to Zones, click Edit.
Next to Security zone, click Add new entry.
In the Name box, type zone.
In the Screen box, type ip-filter-src and click OK.
To save and commit the configuration, click Commit.

CLI Configuration


            
               user@host# set security screen ids-option
                     ip-filter-src ip source-route-option
               user@host# set security zones security-zone
                     zone screen ip-filter-src

Blocking Packets with Either a Loose or Strict Source Route Option Set

J-Web Configuration

CLI Configuration

Related Topics