3
Virus Throttling (5300xl Switches Only)
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Enabling Connection-Rate Filtering and
Configuring a Connection-Rate ACL Using
General Operation of Connection-Rate Filtering . . . . . . . . . . . . . . . . . . . . . 3-5
Filtering Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Sensitivity to Connection Rate Detection . . . . . . . . . . . . . . . . . . . . . . . 3-6
Application Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Operating Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
General Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
For a network that is relatively attack-free: . . . . . . . . . . . . . . . . . . . . . 3-9
For a network that appears to be under significant attack: . . . . . . . . 3-10
Basic Connection-Rate Filtering Configuration . . . . . . . . . . . . . . . . . . . . . 3-11
Global and Per-Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Configuring Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Configuring the Per-Port Filtering Mode . . . . . . . . . . . . . . . . . . . 3-13
Example of a Basic Connection-Rate Filtering Configuration . . 3-14
Viewing and Managing Connection-Rate Status . . . . . . . . . . . . . . . . . 3-16
Viewing the Connection-Rate Configuration . . . . . . . . . . . . . . . . 3-16
Listing and Unblocking the Currently-Blocked Hosts . . . . . . . . . 3-18
Configuring and Applying Connection-Rate ACLs . . . . . . . . . . . . . . . . . . . 3-20
Connection-Rate ACL Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Source IP Address Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Configuring a Connection-Rate ACL Using UDP/TCP Criteria . . . . . 3-23
Applying Connection-Rate ACLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Using CIDR Notation To Enter the ACE Mask . . . . . . . . . . . . . . . . . . 3-26
Example of Using an ACL in a Connection-Rate Configuration . . . . 3-27
3-1