Filtering MLD Messages Based on Source IPv6 Addresses
Context
MLD runs between member hosts and the Layer 3 multicast device that is directly connected to the host network segment. A multicast device processes all received Report messages. To improve security and prevent multicast services from being affected by MLD messages maliciously forged by other devices, you can configure the switch to filter Multicast Listener Discovery (MLD) messages received on an interface. Messages that can be filtered include MLD Query messages, MLD Report and Done messages.
Before configuring MLD messages filtering based on source IPv6 addresses, configure an IPv6 access control list (ACL6) to define the range of source IPv6 addresses for packet filtering. For details about the ACL6 configuration, see ACL Configuration in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - Security.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- (Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.
By default, an Ethernet interface works in Layer 2 mode.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
- Run mld query ip-source-policy basic-acl6-number
A policy is configured to filter MLD Query messages.
By default, the switch does not filter Query messages and processes all the received Query messages.
When configuring an ACL6 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 ACL6, the interface discards Query messages from all source addresses.
- Run mld ip-source-policy basic-acl6-number
A policy is configured to filter Report/Done messages.
By default, the switch does not filter Report/Done messages and processes all the received Report/Done messages.
When configuring an ACL6 rule for the interface, use the permit parameter to configure the interface to accept only Report and Done messages with source addresses in a specified range. If no rule is configured in the ACL6, the interface discards Report and Done messages from all source addresses.