H3C Technologies H3C S12500-X Series Switches - Manual (Page 173)

163
Step Command Remarks
2. Enter IPv6 PIM view.
ipv6 pim [ vpn-instance
vpn-instance-name ]
N/A
3. Configure a C-BSR.
c-bsr ipv6-address [ scope
scope-id ] [ hash-length
hash-length | priority priority ] *
By default, no C-BSR is configured.
4. (Optional.) Configure a legal
BSR address range.
bsr-policy acl6-number
By default, no restrictions are
defined.
Configuring an IPv6 PIM domain border
As the administrative core of an IPv6 PIM-SM domain, the BSR sends the collected RP-set information in
the BSMs to all routers in the IPv6 PIM-SM domain.
An IPv6 PIM domain border is a bootstrap message boundary. Each BSR has its specific service scope.
IPv6 PIM domain border interfaces partition a network into different IPv6 PIM-SM domains. Bootstrap
messages cannot cross a domain border in either direction.
Perform the following configuration on routers that you want to configure as an IPv6 PIM domain border.
To configure an IPv6 PIM border domain:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Configuring an IPv6 PIM
domain border.
ipv6 pim bsr-boundary
By default, no IPv6 PIM domain
border is configured.
Disabling the BSM semantic fragmentation function
Generally, a BSR periodically advertises the RP-set information in BSMs within the IPv6 PIM-SM domain.
It encapsulates a BSM in an IPv6 datagram and might fragment the datagram if the message exceeds the
MTU. In this case, loss of a single IP fragment leads to unavailability of the entire message.
Semantic fragmentation of BSMs can solve this issue. When a BSM exceeds the MTU, it is split to multiple
BSM fragments (BSMFs).
• If the RP-set information for an IPv6 multicast group range is carried in one BSMF, a non-BSR router
directly updates the RP-set information for the group range after receiving the BSMF.
• If the RP-set information for an IPv6 multicast group range is carried in multiple BSMFs, a non-BSR
router updates the RP-set information for the group range after receiving all these BSMFs. Because
the RP-set information contained in each fragment is different, loss of some IP fragments does not
result in dropping of the entire BSM.
The BSM semantic fragmentation function is enabled by default. A device that does not support this
function might regard a fragment as a BSM and thus learns only part of the RP-set information. Therefore,
if such devices exist in the IPv6 PIM-SM domain, you must disable the BSM semantic fragmentation
function on the C-BSRs.
To disable the BSM semantic fragmentation function: