F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices Network Management Configuration Guide-6PW100

870
Ste
p
Command Remarks
1436. Enter system
view.
system-view N/A
1437. Enter IPv6 PIM
view.
pim ipv6 N/A
1438. Configure the BS
period.
c-bsr interval
interval
Optional.
By default, the BS period is determined by the formula "BS
period = (BS timeout timer – 10) / 2." The default BS
timeout timer is 130 seconds, so the default BS period is
(130 – 10) / 2 = 60 (seconds).
The BS period value must be smaller than the BS timeout
timer.
1439. Configure the BS
timeout timer.
c-bsr holdtime
interval
Optional.
By default, the BS timeout timer is determined by the formula
"BS timeout timer = BS period × 2 + 10." The default BS
period is 60 seconds, so the default BS timeout timer is 60 ×
2 + 10 = 130 (seconds).
NOTE:
If yon configure the BS period or the BS timeout timer, the system uses the configured one instead of the
default one.
1799BDisabling BSM semantic fragmentation
Generally, a BSR periodically distributes the RP-set information in bootstrap messages within the IPv6
PIM-SM domain. It encapsulates a BSM in an IPv6 datagram and might split the datagram into fragments
if the message exceeds the MTU. In respect of such IP fragmentation, 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
BSMFs.
• After receiving a BSMF that contains the RP-set information of one group range, a non-BSR router
updates corresponding RP-set information directly.
• If the RP-set information of one group range is carried in multiple BSMFs, a non-BSR router updates
corresponding RP-set information after receiving all these BSMFs.
Because the RP-set information contained in each segment is different, loss of some IP fragments will not
result in dropping of the entire message.
Generally, a BSR performs BSM semantic fragmentation according to the MTU of its BSR interface.
However, the semantic fragmentation of BSMs originated due to learning of a new IPv6 PIM neighbor is
performed according to the MTU of the outgoing interface.
The function of BSM semantic fragmentation is enabled by default. A device that does not support this
function might regard a fragment as an entire message and learns only part of the RP-set information.
Therefore, if such devices exist in the IPv6 PIM-SM domain, you need to disable the semantic
fragmentation function on the C-BSRs.
To disable the BSM semantic fragmentation function:
Ste
p
Command Remarks
1440. Enter system view.
system-view N/A