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- Table of Contents
-
- 07-System
- 01-Track
- 02-BFD
- 03-NQA
- 04-Basic log settings
- 05-Email server
- 06-Session log settings
- 07-Sandbox log settings
- 08-Threat log settings
- 09-Application audit log settings
- 10-NetShare log settings
- 11-URL filtering log settings
- 12-Attack defense log settings
- 13-Reputation log settings
- 14-Bandwidth alarm logs
- 15-Configuration log settings
- 16-Security policy log
- 17-Terminal identification logging
- 18-Heartbeat log settings
- 19-WAF log settings
- 20-Bandwidth management logs
- 21-Report settings
- 22-Session settings
- 23-Signature upgrade
- 24-Software upgrade
- 25-License management
- 26-Administrators
- 27-Date and time
- 28-SNMP
- 29-Configuration management
- 30-Reboot
- 31-About
- 32-Ping
- 33-Tracert
- 34-Packet capture
- 35-Webpage Diagnosis
- 36-Diagnostic Info
- 37-Packet trace
- 38-Fast Internet Access
- Related Documents
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| Title | Size | Download |
|---|---|---|
| 02-BFD | 15.82 KB |
Introduction
Bidirectional forwarding detection (BFD) provides a general-purpose, standard, medium- and protocol-independent fast failure detection mechanism. It can detect and monitor the connectivity of forwarding paths to detect communication failures quickly so that measures can be taken to ensure service continuity and enhance network availability.
BFD can uniformly and quickly detect the failures of the bidirectional forwarding paths between two devices for upper-layer protocols such as routing protocols. The hello mechanism used by upper-layer protocols needs seconds to detect a link failure, while BFD can provide detection measured in milliseconds.
BFD sessions use echo packets to implement detection. Echo packets are encapsulated into UDP packets with port number 3785.
The local end of the link sends echo packets to establish BFD sessions and monitor link status. The peer end does not establish BFD sessions and only forwards the packets back to the originating end. If the local end does not receive echo packets from the peer end within the detection time, it considers the session to be down.
Configure BFD
1. Select System > High Availability > BFD.
2. Configure BFD.
Table 1 BFD configuration items
|
Item |
Description |
|
Echo packet source IPv4 |
Specify a source IPv4 address for echo packets. As a best practice, specify an IPv4 address that is not on the same network segment as any local interface's IP address. This behavior prevents the peer from sending a large number of ICMP redirect packets, which will result in link congestion. |
|
Echo packet source IPv6 |
Specify a source IPv6 address for echo packets. As a best practice, specify an IPv6 address that is not on the same network segment as any local interface's IP address. This behavior prevents the peer from sending a large number of ICMPv6 redirect packets, which will result in link congestion. |
