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


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


Configuration Guide - Reliability

S1720, S2700, S5700, and S6720 V200R010C00

This document describes the configuration of BFD, DLDP, VRRP, SmartLink, CFM, EFM, Y.1731 and MAC swap loopback to ensure reliability on the device.

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).


If a designated router (DR) on the shared network segment becomes faulty, Protocol Independent Multicast (PIM) neighbor relationships time out. This triggers a new DR election among PIM neighbors, interrupting multicast data transmission. The interruption period, usually in seconds, is at least as long as the timeout interval of the neighbor relationship.

After detecting a fault on the peer, BFD immediately instructs the PIM module to trigger a new DR election without waiting for timeout of the neighbor relationship.

BFD for PIM can quickly detect faults on the Assert winner and is also applicable to Assert election on a shared network segment.

Table 3-4 lists the PIM convergence time.

Table 3-4  PIM convergence time

BFD Session

Link Fault Detection Mechanism

Convergence Time

Not bound

Neighbor relationship timeout



BFD session in Down state



Figure 3-14  BFD for PIM

In Figure 3-14, on the shared network segment connected to user hosts, downstream interface Interface1 on SwitchC and downstream interface Interface2 on SwitchD establish a PIM BFD session and send BFD control packets to monitor the link status.

SwitchC functions as the DR and Interface1 is responsible for forwarding multicast data. If Interface1 becomes faulty, BFD fast notifies the RM of the session status and the RM notifies the PIM module. The PIM module then triggers a new DR election. SwitchD quickly begins functioning as the new DR and Interface2 begins forwarding multicast data to the receivers.

Updated: 2019-12-28

Document ID: EDOC1000141941

Views: 109670

Downloads: 529

Average rating:
This Document Applies to these Products

Related Version

Related Documents

Previous Next