Configuring Inline Normalization

Note	This section applies to Snort 2 preprocessors. For information on Snort 3 inspectors, see https://www.cisco.com/go/snort3-inspectors.

Before you begin

If you want to normalize or drop offending packets, enable Inline Mode as described in Preprocessor Traffic Modification in Inline Deployments. The managed device must also be deployed inline.

Step 1

Choose Policies > Access Control, then click Network Analysis Policy or Policies > Access Control > Intrusion, then click Network Analysis Policies.

Note	If your custom user role limits access to the first path listed here, use the second path to access the policy.

Step 2

Click Snort 2 Version next to the policy you want to edit.

Step 3

Click Edit ( edit icon ) next to the policy you want to edit.

If View ( View button ) appears instead, the configuration belongs to an ancestor domain, or you do not have permission to modify the configuration.

Step 4

Click Settings in the navigation panel (NOT the caret; click the word).

Step 5

If Inline Normalization under Transport/Network Layer Preprocessors is disabled, click Enabled.

Step 6

Click Edit ( edit icon ) next to Inline Normalization.

Step 7

Step 8

To save changes you made in this policy since the last policy commit, click Policy Information, then click Commit Changes.

If you leave the policy without committing changes, cached changes since the last commit are discarded if you edit a different policy.

If you want the inline normalization Minimum TTL option to generate intrusion events, enable either or both packet decoder rules 116:429 (IPv4) and 116:270 (IPv6). For more information, see Setting Intrusion Rule States, and Inline Normalization Options.
Deploy configuration changes.