No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Configuration Guide - IP Multicast

S7700 and S9700 V200R013C00

This document describes the configurations of IP multicast, including IP multicast basics, IGMP, MLD, IPv4 PIM, IPv6 PIM, MSDP, multicast VPN, layer 3 multicast CAC, IPv4 multicast route management, IPv6 multicast route management, IGMP snooping, MLD snooping, static multicast MAC address, multicast VLAN replication, layer 2 multicast CAC, multicast network management.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
PIM BFD

PIM BFD

A network device must detect a communications fault between adjacent devices quickly so that the upper layer protocol can rectify the fault and prevent a service interruption.

Bidirectional Forwarding Detection (BFD) provides uniform detection for all media and protocol layers within milliseconds. Two systems set up a BFD session and periodically send BFD control packets along the path between them. If one system does not receive BFD control packets within a specified period, the system considers that a fault has occurred on the path.

Implementation

If the current DR or assert winner on the shared network segment is faulty in a multicast scenario, other PIM neighbors start a new DR election or assert election after the neighbor relationship or the Assert timer times out. Multicast data transmission is interrupted for no less than the neighbor timeout interval or the Assert timer length, usually several seconds.

Because PIM BFD detects the link status on a shared network segment within milliseconds, it responds quickly to PIM neighbor faults. If an interface enabled with PIM BFD does not receive BFD control packets from the DR or assert winner within the detection interval, it considers DR or assert winner faulty. BFD quickly notifies the routing module of the session status, and the routing module then notifies PIM. PIM triggers a new DR election or assert election without waiting for the neighbor relationship or the Assert timer to expire. PIM BFD reduces the service interruption time and improves data transmission reliability.

PIM BFD is applicable only to PIM-SM networks.

Figure 4-15 shows a shared network segment connected to user hosts. Downstream Interface1 on RouterB and downstream Interface2 on RouterC establish a PIM BFD session and send BFD control packets to detect link status.

RouterB functions as the DR and its downstream interface Interface1 is responsible for forwarding multicast data. If Interface1 fails, BFD quickly notifies the routing module of the session status, and the routing module notifies PIM, which then triggers a new DR election. RouterC becomes the new DR and its downstream interface Interface2 forwards multicast data to the receivers quickly.

Figure 4-15  PIM BFD
Translation
Download
Updated: 2019-04-08

Document ID: EDOC1100065742

Views: 47867

Downloads: 46

Average rating:
This Document Applies to these Products
Related Version
Related Documents
Share
Previous Next