Filtering IGMP Messages Based on Source IP Addresses
Context
A Layer 3 multicast router directly connected to a user network segment processes all the IGMP messages received. To improve security and prevent multicast services from being affected by IGMP messages maliciously forged by other devices, you can configure IGMP message filtering on router interfaces connected to hosts. The router supports filtering of IGMP Query, Report and Leave messages.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- Run igmp query ip-source-policy { basic-acl-number | acl-name acl-name }
A policy is configured on the interface to filter Query messages based on source IP addresses.
By default, the router does not filter Query messages and processes all the received Query messages.
When configuring an ACL rule for the interface, use the permit parameter to configure the interface to accept only Query messages with source addresses in a specified range. If no rule is configured in the ACL, the interface denies all IGMP Query messages.
- Run igmp ip-source-policy [ basic-acl-number | acl-name acl-name ]
A policy is configured on the interface to filter Report/Leave messages based on source IP addresses.
By default, the router does not filter Report/Leave messages and processes all the received Report/Leave messages.
After Report/Leave message filtering is configured without specifying an ACL, the router processes Report/Leave messages based on source IP addresses as follows:
If the source IP address of a Report/Leave message is 0.0.0.0 or on the same network segment as the IP address of the inbound interface, the router processes the Report/Leave message.
If the source IP address of a Report/Leave message is on a different network segment than the IP address of the inbound interface, the router discards the Report/Leave message.
When configuring an ACL rule for the interface, use the permit parameter to configure the interface to accept only Report/Leave messages with source addresses in a specified range. If no rule is configured in the ACL, the interface denies all IGMP Report/Leave messages.
