Firewall Filter Configuration Guidelines

To configure firewall filters, you include statements at the [edit firewall] hierarchy level of the configuration:

 firewall { 
 	 filter filter-name { 
 	 	 term term-name {
 	 	 	 from {
 	 	 	 	 match-conditions;
 	 	 	 }
 	 	 	 then {
 	 	 	 	 action; 
 	 	 	 	 action-modifiers; 
 	 	 	 }
 	 	 }
 	 }
 }
 

The following RFCs define the standards supported by certain aspects of the filtering software:

• RFC 792, Internet Control Message Protocol (ICMP)
• RFC 2474, Definition of the Differentiated Services (DS) Field
• RFC 2475, An Architecture for Differentiated Services
• RFC 2597, Assured Forwarding PHB
• RFC 2598, An Expedited Forwarding PHB

This chapter describes the following tasks for configuring firewall filters:

• Minimum Firewall Filter Configuration
• Configure Firewall Filters
• Apply Firewall Filters
• Define Interface Groups
• Configure Policing