H3C Technologies H3C S10500 Series Switches - Manual (Page 337)

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You can configure the forwarding boundary for a specific IPv6 multicast group or an IPv6 multicast group
with the scope field in its group address being specified on all interfaces that support IPv6 multicast
forwarding. A multicast forwarding boundary sets the boundary condition for the IPv6 multicast groups
in the specified range or scope. If the destination address of an IPv6 multicast packet matches the set
boundary condition, the packet will not be forwarded. Once an IPv6 multicast boundary is configured
on an interface, this interface can no longer forward IPv6 multicast packets (including those sent from the
local device) or receive IPv6 multicast packets.
Follow these steps to configure an IPv6 multicast forwarding range:
To do... Use the command... Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure an IPv6 multicast
forwarding boundary
multicast ipv6 boundary
{ ipv6-group-address prefix-length |
scope { scope-id | admin-local |
global | organization-local |
site-local } }
Required
No forwarding boundary by
default.
Configuring the IPv6 multicast forwarding table size
The switch maintains the corresponding forwarding entry for each IPv6 multicast packet that it receives.
Excessive IPv6 multicast routing entries, however, can exhaust the switch’s memory and cause lower
performance. You can set a limit on the number of entries in the IPv6 multicast forwarding table based
on the actual networking situation and the performance requirements. If the configured maximum
number of IPv6 multicast forwarding table entries is smaller than the current value, the entries in excess
are not immediately deleted. Instead, the IPv6 multicast routing protocol that runs on the switch deletes
them. The switch no longer adds new IPv6 multicast forwarding entries until the number of existing IPv6
multicast forwarding entries comes down below the configured value.
When the switch forwards IPv6 multicast traffic, it replicates a copy of the IPv6 multicast traffic for each
downstream node and forwards the traffic. Each of these downstream nodes forms a branch of the IPv6
multicast distribution tree. You can configure the maximum number of downstream nodes—namely, the
maximum number of outgoing interfaces—for a single entry in the IPv6 multicast forwarding table to
lessen the burden on the switch for replicating IPv6 multicast traffic. If the configured maximum number
of downstream nodes for a single IPv6 multicast forwarding entry is smaller than the current number, the
downstream nodes in excess are not deleted immediately. Instead, the IPv6 multicast routing protocol
deletes them. The switch no longer adds new IPv6 multicast forwarding entries for newly added
downstream nodes until the number of existing downstream nodes comes down below the configured
value.
Follow these steps to configure the IPv6 multicast forwarding table size:
To do... Use the command... Remarks
Enter system view system-view —
Configure the maximum number of
entries in the IPv6 multicast
forwarding table
multicast ipv6 forwarding-table
route-limit limit Optional
1000 by default.
Configure the maximum number of
downstream nodes for a single
IPv6 multicast forwarding entry
multicast ipv6 forwarding-table
downstream-limit limit Optional
128 by default.