MLD-Snooping Configuration I Table of Contents Table of Contents Chapter 1 MLD-Snooping Configuration.............................................................................................1 1.1 IPv6 Multicast Overview..........................................................................................................1 1.2 MLD-Snooping Multicast Configuration Tasks.....................................................................1 1.2.1 Enabling/Disabling MLD-Snooping Multicast...........................................................1 1.2.2 Enabling/Disabling the Solicitation of Hardware Forward of Multicast Group....2 1.2.3 Adding/Deleting the Static Multicast Address of VLAN.......................................... 2 1.2.4 Setting Router Age Timer of MLD-Snooping............................................................2 1.2.5 Setting Response Time Timer of MLD-Snooping....................................................3 1.2.6 Configuring Querier of MLD-Snooping..................................................................... 3 1.2.7 Setting the Port of the Static Multicast Router.........................................................4 1.2.8 Enabling/Disabling Immediate Leave........................................................................4 1.2.9 Monitoring and Maintaining MLD-Snooping Multicast............................................4 II MLD-Snooping Configuration Chapter 1 MLD-Snooping Configuration 1.1 IPv6 Multicast Overview The task of MLD snooping is to maintain the forwarding relationship of IPv6 group addresses in VLAN and synchronize with the change of the multicast group, enabling the data to be forwarded according to the topology of the multicast group. Its functions include monitoring MLD-snooping packets, maintaining the table between group address and VLAN, keep the MLD-snooping host the same with the MLD-snooping router and solve the flooding problems. When a L2 device has not got MLD snooping run, the multicast data will be broadcast at the second layer; when the L2 device gets MLD snooping run, the multicast data of the known multicast group will not be broadcast at the second layer but be sent to the designated receiver, and the unknown multicast data will be dropped. Note: Because MLD-Snooping realizes the above functions by listening the query message and report message of MLD-Snooping, MLD-Snooping can function properly only when it works on the multicast router, that is, the switch must periodically receive the MLD-Snooping query information from the router. The router age timer of MLD-Snooping must be set to a time value that is bigger than the group query period of the multicast router connecting MLD-Snooping. You can check the multicast router information in each VLAN by running show ipv6 mld-snooping. 1.2 MLD-Snooping Multicast Configuration Tasks  Enabling/Disabling MLD-Snooping  Enabling/Disabling the Solicitation of Hardware Forward of Multicast Group  Adding/Deleting the Static Multicast Address of VLAN  Setting Router Age Timer of MLD-Snooping  Setting Response Time Timer of MLD-Snooping  Setting the Port of the Static Multicast Router  Setting the Immediate Leave Function  Monitoring and Maintaining MLD-Snooping 1.2.1 Enabling/Disabling MLD-Snooping Multicast Run the following commands in global configuration mode. Command Purpose ipv6 mld-snooping Enables MLD snooping multicast. 1 MLD-Snooping Configuration no ipv6 mld-snooping Disables MLD snooping. Note: After MLD-Snooping is enabled, when DLF occurs on multicast packets (that is, the destination address is not registered in the swap chip through the MLD-Snooping), all multicast packets whose destination addresses are not registered on any port will be dropped. 1.2.2 Enabling/Disabling the Solicitation of Hardware Forward of Multicast Group Run the following commands in global configuration mode. Command Purpose ipv6 mld-snooping solicitation Enables the solicitation of hardware forward of multicast group. no ipv6 mld-snooping solicitation Disables the solicitation of hardware forward of multicast group. 1.2.3 Adding/Deleting the Static Multicast Address of VLAN The static multicast address can make some MLD-Snooping hosts receive the corresponding multicast packets. Run the following commands in global configuration mode. Command Purpose ipv6 mld-snooping vlan vlan_id static X:X:X:X::X Adds the static multicast address of VLAN. interface intf_name no ipv6 mld-snooping vlan vlan_id static Deletes static multicast address of VLAN. X:X:X:X::X interface intf_name 1.2.4 Setting Router Age Timer of MLD-Snooping The router age timer is used to monitor whether the MLD-Snooping querier exists or not; the MLD-Snooping querier maintenance is used to maintain and manage the multicast address by sending the query packets and MLD-Snooping works by independence on the communication between MLD-Snooping querier and host. Run the following commands in global configuration mode. Command Operation ipv6 mld-snooping timer router-age timer_value Sets the router age of MLD-Snooping. no ipv6 mld-snooping timer router-age Resumes the default router age of MLD-Snooping. 2 MLD-Snooping Configuration Note: The settings of the timer requires to refer to the query period settings of the MLD-Snooping querier for it cannot be smaller than the query period; you are recommended to set the router age timer to the triple of the query period. By default the router age timer is set to be 260 seconds of MLD-Snooping. 1.2.5 Setting Response Time Timer of MLD-Snooping The Response Time timer means the threshold time for the host to report the multicast after MLD-Snooping querier sends the query packets; if this report packet is not received after the timer ages, the switch will delete this multicast address. Run the following commands in global configuration mode. Command Operation ipv6 mld-snooping timer response-time Sets the value of the response time of timer_value MLD-Snooping. no ipv6 mld-snooping timer response-time Resumes the default value of the response time of MLD-Snooping. Note: The value of the timer cannot be set too small, or the multicast communication may be unstable. By default the response time is set to be 10 seconds of MLD-Snooping. 1.2.6 Configuring Querier of MLD-Snooping If the multicast router does not exist in VLAN where MLD-snooping is activated,the querier function of MLD-snooping can be used to imitate the multicast routerto regularly send MLD-snooping query message. (The function is global, that is, it can beenabled or disabled in VLAN where MLD-snooping is globally enabled) When the multicast router does not exist in LAN and multicast flow does not needrouting, the automatic query function of the switch can be activated through MLD-snooping , enabling MLD-snooping to work properly. Run the following commands in global configuration mode. Command Operation [no] ipv6 mld-snooping querier Configures the querier of MLD-snooping. The optional parameter [address [ip_addr]] address is the source IP address of query message. The IGMP-snooping querier function is disabled by default. By default, the source IP address of the fake Query packet is FE80::3FF:FEFE:FD00:1. Note: 3 MLD-Snooping Configuration If the querier function is enabled, the function is disabled when the multicast router exists in VLAN; the function can be automatically activated when the multicast router times out. 1.2.7 Setting the Port of the Static Multicast Router After a port is set to be a static multicast port, all the MLD-Snooping report packets and done packets will be transmitted to this port. Run the following commands in global configuration mode. Command Operation ipv6 mld-snooping vlan WORD mrouter interface Sets the static multicast router’s port of MLD inft_name snooping in Vlan word. no ipv6 mld-snooping vlan WORD mrouter Deletes the static multicast router’s port of interface inft_name MLD snooping in Vlan word. 1.2.8 Enabling/Disabling Immediate Leave Run the following commands in global configuration mode. Command Purpose ipv6 mld-snooping vlan WORD Enables the immediate-leave functionality. immediate-leave no ipv6 mld-snooping vlan WORD Resumes the default settings. immediate-leave 1.2.9 Monitoring and Maintaining MLD-Snooping Multicast Run the following commands in EXEC mode: Command Operation show ipv6mld-snooping Displays the configuration of MLD-Snooping. show ipv6 mld-snooping timer Displays the clock of MLD-Snooping. show ipv6mld -snooping groups Displays the multicast group of MLD-Snooping. show ipv6 mld-snooping statistics Displays the statistics information of MLD-Snooping. show ipv6 mld-snooping vlan Displays the configuration of MLD-Snooping in VLAN. show ipv6 mld-snooping mac Displays the multicast MAC addresses recorded by 4 MLD-Snooping Configuration MLD snooping. The MLD-Snooping information is displayed below: Switch#show ipv6 mld-snooping Global MLD snooping configuration: ----------------------------------- Globally enable : Enabled Querier : Enabled Querier address : FE80::3FF:FEFE:FD00:1 Router age : 260 s Response time : 10 s Handle Solicitation : Disabled Vlan 1: ---------- Running Routers: SWITCH(querier); Displays the multicast group of MLD-Snooping. Switch#show ipv6 mld--snooping groups Vlan Group Type Port(s) ---- --------------- ---- ------------------------------------- 1 FF02::1:FF32:1B9B MLD G0/3 1 FF02::1:FF00:2 MLD G0/3 1 FF02::1:FF00:12 MLD G0/3 1 FF02::1:FF13:647D MLD G0/3 2 FF02::1:FF00:2 MLD G0/2 2 FF02::1:FF61:9901 MLD G0/2 Displays MLD-Snooping Snooping Timer Switch#show ipv6 mld-snooping timers vlan 1 Querier on port 0 : 251 # Querier on port 0: 251 means the timeout time of the ageing timer of the router. vlan 2 multicast address 3333.0000.0005 response time : this shows the time period from receiving a multicast query packet to the present; if there is no host to respond when the timer times out, the port will be canceled. The MLD-snooping statistics information is displayed below: Switch#show ipv6 mld-snooping statistics vlan 1 ------------ v1_packets:0 quantity of v1 packets v2_packets:6 quantity of v2 packets general_query_packets:5 Quantity of general query packets special_query_packets:0 Quantity of special query packets 5 MLD-Snooping Configuration listener_packets:6 Quantity of Report packets done_packets:0 Quantity of Leave packets send_query_packets:0 Quantity of sending packets err_packets:0 Quantity of error packets Displays multicast mac information of the operating MLD-Snooping Switch#show ipv6 mld-snooping mac Vlan Mac Ref Flags ---- --------------- ---- ------ 1 3333:0000:0001 1 2 2 3333:ff61:9901 1 0 FF02::1:FF61:9901 1 3333:0000:0002 1 2 1 3333:ff00:0002 1 0 FF02::1:FF00:2 1 3333:ff00:0012 1 0 FF02::1:FF00:12 1 3333:ff13:647d 1 0 FF02::1:FF13:647D 1 3333:ff32:1b9b 1 0 FF02::1:FF32:1B9B 2 3333:ff00:0002 1 0 FF02::1:FF00:2 1 3333:ff00:0001 1 2 1 3333:ff8e:7000 1 2 6