![background image](http://html1.mh-extra.com/html/foundry-networks/fastiron-edge-switch-x424/fastiron-edge-switch-x424_manual_2324269675.webp)
Configuring BGP4
December 2005
© Foundry Networks, Inc.
21 - 103
NOTE:
The Foundry implementation of dynamic route refresh supports negotiation of IP version 4 unicasts
only.
•
RFC 2918, which describes the dynamic route refresh capability
The dynamic route refresh capability is enabled by default and cannot be disabled. When the Layer 3 Switch
sends a BGP4 OPEN message to a neighbor, the Layer 3 Switch includes a Capability Advertisement to inform
the neighbor that the Layer 3 Switch supports dynamic route refresh.
NOTE:
The option for dynamically refreshing routes received from a neighbor requires the neighbor to support
dynamic route refresh. If the neighbor does not support this feature, the option does not take effect and the
software displays an error message. The option for dynamically re-advertising routes to a neighbor does not
require the neighbor to support dynamic route refresh.
To use the dynamic refresh feature, use either of the following methods.
Dynamically Refreshing Routes
The following sections describe how to dynamically refresh BGP4 routes to place new or changed filters into
effect.
To request a dynamic refresh of all routes from a neighbor, enter a command such as the following:
FESX424 Router(config-bgp-router)# clear ip bgp neighbor 192.168.1.170 soft in
This command asks the neighbor to send its BGP4 table (Adj-RIB-Out) again. The Layer 3 Switch applies its
filters to the incoming routes and adds, modifies, or removes BGP4 routes as necessary.
Syntax:
clear ip bgp neighbor all | <ip-addr> | <peer-group-name> | <as-num> [soft-outbound | soft [in | out]]
The
all
| <ip-addr> | <peer-group-name> | <as-num> specifies the neighbor. The <ip-addr> parameter specifies a
neighbor by its IP interface with the Layer 3 Switch. The <peer-group-name> specifies all neighbors in a specific
peer group. The <as-num> parameter specifies all neighbors within the specified AS. The
all
parameter specifies
all neighbors.
The
soft-outbound
parameter updates all outbound routes by applying the new or changed filters, but sends only
the existing routes affected by the new or changed filters to the neighbor.
The
soft [in | out]
parameter specifies whether you want to refresh the routes received from the neighbor or sent
to the neighbor:
•
soft in
does one of the following:
•
If you enabled soft reconfiguration for the neighbor or peer group,
soft in
updates the routes by
comparing the route policies against the route updates that the Layer 3 Switch has stored. Soft
reconfiguration does not request additional updates from the neighbor or otherwise affect the session
with the neighbor. See “Using Soft Reconfiguration” on page 21-100.
•
If you did not enable soft reconfiguration,
soft in
requests the neighbor’s entire BGP4 route table (Adj-
RIB-Out), then applies the filters to add, change, or exclude routes.
•
If a neighbor does not support dynamic refresh,
soft in
resets the neighbor session.
•
soft out
updates all outbound routes, then sends the Layer 3 Switch’s entire BGP4 route table (Adj-RIB-Out)
to the neighbor, after changing or excluding the routes affected by the filters.
If you do not specify
in
or
out
, the Layer 3 Switch performs both options.
NOTE:
The
soft-outbound
parameter updates all outbound routes by applying the new or changed filters, but
sends only the existing routes affected by the new or changed filters to the neighbor. The
soft out
parameter
updates all outbound routes, then sends the Layer 3 Switch’s entire BGP4 route table (Adj-RIB-Out) to the
neighbor, after changing or excluding the routes affected by the filters. Use
soft-outbound
if only the outbound
policy is changed.
Summary of Contents for FastIron Edge Switch X424
Page 36: ...Foundry Configuration Guide for the FESX FSX and FWSX 2 12 Foundry Networks Inc December 2005...
Page 56: ...Foundry Configuration Guide for the FESX FSX and FWSX 3 20 Foundry Networks Inc December 2005...
Page 70: ...Foundry Configuration Guide for the FESX FSX and FWSX 4 14 Foundry Networks Inc December 2005...
Page 198: ...Foundry Configuration Guide for the FESX FSX and FWSX 8 38 Foundry Networks Inc December 2005...
Page 316: ...Foundry Configuration Guide for the FESX FSX and FWSX 12 26 Foundry Networks Inc December 2005...
Page 350: ...Foundry Configuration Guide for the FESX FSX and FWSX 15 12 Foundry Networks Inc December 2005...
Page 458: ...Foundry Configuration Guide for the FESX FSX and FWSX 18 18 Foundry Networks Inc December 2005...
Page 712: ...Foundry Configuration Guide for the FESX FSX and FWSX 22 32 Foundry Networks Inc December 2005...
Page 760: ...Foundry Configuration Guide for the FESX FSX and FWSX A 34 Foundry Networks Inc December 2005...
Page 796: ...Foundry Configuration Guide for the FESX FSX and FWSX C 18 Foundry Networks Inc December 2005...
Page 820: ...Foundry Configuration Guide for the FESX FSX and FWSX E 10 Foundry Networks Inc December 2005...