Mld introduction – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual
Page 786
MLD and MLD Snooping Introduction and Commands
Software Reference for x310 Series Switches
32.2
AlliedWare Plus
TM
Operating System - Version 5.4.4C
C613-50046-01 REV A
MLD Introduction
Multicast Listener Discovery (MLD) is used to exchange membership status information
between IPv6 routers that support multicasting and members of multicast groups on a
network segment. Host membership in a multicast group is reported by individual
member hosts, and membership status is periodically polled by multicast routers.
MLD is defined in RFC 2710, "Multicast Listener Discovery (MLD) for IPv6." and MLDv2 is
defined in RFC 3810, "Multicast Listener Discovery Version 2 (MLDv2) for IPv6."
AlliedWare Plus supports both RFC 2710 and RFC 3810 for MLD and MLDv2 respectively.
MLD requires memory for storing data structures, as well as the hardware tables to
implement hardware routing. As the number of ports, VLANs, static and dynamic groups
increases then more memory is consumed. You can track the memory used for MLD with
the command:
Static and dynamic groups (LACP), ports and VLANs are not limited for MLD. For VLANs,
this allows you to configure MLD across more VLANs with fewer ports per VLAN, or fewer
VLANs with more ports per VLAN. For LACPs, you can configure MLD across more LACP
groups with fewer ports per LACP, or fewer LACP groups with more ports per LACP.
Sample running-config showing MLD configuration on interface vlan2
Note
There is a 100 MLD interface limit when applying MLD commands to multiple
VLANs. Only the first 100 VLANs have the required multicast structures added
to the interfaces that allow multicast routing. See the limits for MLD interfaces
depending on the number of VLANs, ports, static and dynamic groups as
shown in the relevant product data sheet for your switch.
awplus#
show memory pools nsm | grep MLD
!
ipv6 forwarding
!
interface vlan2
ipv6 address 2001:0db8::12:252/64
ipv6 enable
ipv6 mld
!
Note
IPv6 must be enabled on an interface with the
command, IPv6
forwarding must be enabled globally for routing IPv6 with the
command.
Note
The IPv6 addresses shown use the address space 2001:0db8::/32, defined in RFC
3849 for documentation purposes. These addresses should not be used for
practical networks (other than for testing purposes) nor should they appear on
any public network.