HP 5500 Ei 5500 Si Switch Series Configuration Guide

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Configuring BFD basic functions 
The BFD basic functions configuration is the basis for configuring BFD for other protocols.  
Configuration prerequisites 
Before configuring BFD basic functions, complete the following tasks: 
•  Configure the network layer addresses of the interf aces so that adjacent nodes are reachable to 
each other at the network layer 
•   Configure the routing protocols that support BFD 
Configuration procedure 
To configure BFD basic functions:  
Step Command Remarks 
1....

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Step Command Remarks 
8.  Configure the minimum 
interval for receiving BFD 
control packets.  bfd min-receive-interval 
value  Optional. 
For relevant information, see the 
description of the 
Required Min RX 
Interval  field in  BFD packet 
format .  
400 

milliseconds by default. 
9.   Configure the detection time 
multiplier.  bfd detect-multiplier
 value   Optional. 
For relevant information, see the 
description of the 
Detect Mult field 
in  BFD packet format .  
5

 by default. 
10....

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Configuring track 
Only the HP 5500 EI Switch Series supports BFD, VRRP, and PBR configurations.  
Track overview 
Introduction to collaboration 
The track module works between application and detection modules, as shown in Figure 55 . It shields the 
differences between various detection modules from application modules. 
Collaboration is enabled after you associate the  track module with a detection module and an 
application module. The detection module probes specific objects such as interface...

 201 
The following detection modules can be associated with the track module: 
•   NQA 
•   BFD (available only on the HP 5500 EI) 
•   Interface management module 
Collaboration between the track module and an application module 
After being associated with an application module, wh en the status of the track entry changes, the track 
module notifies the application module, which then takes proper actions.  
The following application modules can be associated with the track module: 
•   Virtual Router...

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Task Remarks 
Associating the track module 
with a detection module Associating track with NQA  
Required 
Use any of the 
approac

hes. 
Associating track with BFD (available only on 
the HP 5500 EI) 
Associating track with interface management 
Associating the track module 
with an application module Associating track with VRRP (available only on 
the HP

 5500 EI)  Required 
Use any of the 
approaches. 
Associating track with static routing 
Associating track with PBR (available only on 
the HP...

 203 
Associating track with BFD (available only on the HP 5500 EI) 
BFD supports the control packet mode and echo mode. Only echo-mode BFD can be associated with a 
track entry.  
The BFD functions as follows when it is associated with a track entry: 
•  If the BFD detects that the link fails, it informs the track entry of the link failure. The track module then 
sets the track entry to the Negative state.  
•   If the BFD detects that the link is normal, the track module sets the track entry to the...

 204 
Step Command Remarks 
2.  Associate track with 
interface 
management.  Create a track entry, associ
ate it with the interface 
management module to monitor the physical status of 
an interface, and specify th e delay time for the track 
module to notify the asso ciated application module 
when the track entry status changes: 
track  track-entry-number  interface interface-type 
interface-number [ delay  { negative negative-time  | 
positive  positive-time  } * ]  
Create a track entry, associ ate...

 205 
•  M o n i t o r  t h e  AV F  s t a t u s  f ro m  t h e  l i s t e n i n g  V F  ( LV F ) ,  w h i c h  re f e r s  t o  t h e  V F  i n  l i s t e n i n g  s t a t e.  W h e n  t h e  
AVF fails, the LVF that is operating in switchover mode becomes the new AVF to ensure continuous 
forwarding. 
VRRP tracking is not valid on an IP address owner. An IP address owner refers to a router when the IP 
address of the virtual router is the IP address of  an interface on the router in the VRRP group....

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Associating track with static routing 
A static route is a manually configured route. With a static route configured, packets to the specified 
destination are forwarded through the path specified by the administrator. 
The disadvantage of using static routes is that they cannot adapt to network topology changes. Faults or 
topological changes in the network can make th e routes unreachable, causing network breaks. 
To prevent this problem, configure another route to  back up the static route....

 207 
 NOTE:  
You can associate a nonexistent track entry with a static  route. The association takes effect only after you
use the  track command to create the track entry. 
 
Associating track with PBR (available only on the HP 5500 EI) 
Policy-based routing (PBR) is a routing mechanism ba sed on user-defined policies. Different from the 
traditional destination-based routing mechanism, PBR enables you to use a policy (based on the source 
address and other criteria) to route packets. 
PBR cannot...