Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 122)

94 Multi-Service IronWare Routing Configuration Guide
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Filtering
When a route filter is changed (created, modified or deleted) by a user, the filter change notification
will be sent to all relevant protocols, so that protocols can take appropriate actions. For example if
BGP4 is using a route-map (say MapX) to control the routes advertised to a particular peer, the
change of route-map (MapX) will cause BGP4 to re-evaluate the advertised routes, and make the
appropriate advertisements or withdrawals according to the new route-map policy.
A route filter change action can happen in three ways.
1. A new filter is defined (created).
This filter name may be already referenced by an application. The application needs to be
notified of the addition of the new filter, and will bind to and use the new filter. In general, if a
filter name is referenced by an application, but is not actually defined, the application assumes
the default deny action for the filter.
2. An existing filter is undefined (removed).
If the deleted filter is already used and referenced by an application, the application will unbind
itself from the deleted filter.
3. An existing filter is modified (updated).
If the filter is already used and referenced by an application, the application will be notified.
Protocols are automatically notified when a route filter is created, deleted or modified. In addition,
when a protocol is notified of a filter change, appropriate steps are taken to apply the new or
updated filter to existing routes.
Commands for dynamic route filter updating
In order to allow multiple filter updates to be processed together by applications, the device waits
10 seconds by default before notifying applications of the filter change. You can force an
immediate update notification or modify the time delay from when a change is made to a route
filter to when the protocols are notified.
Route filter update delay settings can be configured using the commands shown here.
Setting a time delay for route filter update notification
Set the amount of time that the device waits before sending filter addition, deletion and
modification notification to protocols using the following command.
Brocade(config)# filter-change-update-delay 100
Syntax: [no] filter-change-update-delay delay-time
The delay-time variable specifies the amount of time in seconds that the device waits before
sending filter addition, deletion and modification notification to protocols. The valid range is 0 to
600 seconds. If you set the value to 0, filter change notifications will not be automatically sent to
protocols. The default value is 10 seconds.
NOTE
The filter-change-update-delay command also affects a route map that is being used in a PBR policy.
Performing an immediate route filter update
To force an immediate filter update to the relevant protocols, use the following command.
Brocade(config)# clear filter-change-update
Syntax: clear filter-change-update