Perform this task
to configure inbound soft reconfiguration using the
bgp
soft-reconfig-backup command for BGP peers that do
not support the route refresh capability. BGP peers that support the route
refresh capability are unaffected by the configuration of this command. Note
that the memory requirements for storing the inbound update information can
become quite large.
SUMMARY STEPS
-
enable
-
configure
terminal
-
router
bgp
autonomous-system-number
-
bgp
log-neighbor-changes
-
bgp
soft-reconfig-backup
-
neighbor
{ip-address |
peer-group-name }
remote-as
autonomous-system-number
-
neighbor
{ip-address |
peer-group-name }
soft-reconfiguration [inbound ]
-
neighbor
{ip-address |
peer-group-name }
route-map
map-name
{in |
out }
- Repeat Steps
6 through 8 for every peer that is to be configured with inbound soft
reconfiguration.
-
exit
-
route-map
map-name
[permit
|
deny ] [sequence-number ]
-
set
ip
next-hop
ip-address
-
end
-
show
ip
bgp
neighbors
[neighbor-address ]
-
show
ip
bgp
[network ]
[network-mask ]
DETAILED STEPS
| |
Command or Action |
Purpose |
| Step 1 |
enable
|
Enables
privileged EXEC mode.
|
| Step 2 |
configure
terminal
Device# configure terminal
|
Enters global
configuration mode.
|
| Step 3 |
router
bgp
autonomous-system-number
Device(config)# router bgp 45000
|
Enters router
configuration mode for the specified routing process.
|
| Step 4 |
bgp
log-neighbor-changes
Device(config-router)# bgp log-neighbor-changes
|
Enables logging
of BGP neighbor resets.
|
| Step 5 |
bgp
soft-reconfig-backup
Device(config-router)# bgp soft-reconfig-backup
|
Configures a
BGP speaker to perform inbound soft reconfiguration for peers that do not
support the route refresh capability.
|
| Step 6 |
neighbor
{ip-address |
peer-group-name }
remote-as
autonomous-system-number
Device(config-router)# neighbor 192.168.1.2 remote-as 40000
|
Adds the IP
address of the neighbor in the specified autonomous system to the IPv4
multiprotocol BGP neighbor table of the local device.
|
| Step 7 |
neighbor
{ip-address |
peer-group-name }
soft-reconfiguration [inbound ]
Device(config-router)# neighbor 192.168.1.2 soft-reconfiguration inbound
|
Configures the
Cisco software to start storing updates.
-
All the
updates received from this neighbor will be stored unmodified, regardless of
the inbound policy. When inbound soft reconfiguration is done later, the stored
information will be used to generate a new set of inbound updates.
|
| Step 8 |
neighbor
{ip-address |
peer-group-name }
route-map
map-name
{in |
out }
Device(config-router)# neighbor 192.168.1.2 route-map LOCAL in
|
Applies a
route map to incoming or outgoing routes.
|
| Step 9 |
Repeat Steps
6 through 8 for every peer that is to be configured with inbound soft
reconfiguration.
|
|
| Step 10 |
exit
Device(config-router)# exit
|
Exits router
configuration mode and enters global configuration mode.
|
| Step 11 |
route-map
map-name
[permit
|
deny ] [sequence-number ]
Device(config)# route-map LOCAL permit 10
|
Configures a
route map and enters route-map configuration mode.
|
| Step 12 |
set
ip
next-hop
ip-address
Device(config-route-map)# set ip next-hop 192.168.1.144
|
Specifies
where output packets that pass a match clause of a route map for policy
routing.
- In this example, the ip
address is set to 192.168.1.144.
|
| Step 13 |
end
Device(config-route-map)# end
|
Exits
route-map configuration mode and enters privileged EXEC mode.
|
| Step 14 |
show
ip
bgp
neighbors
[neighbor-address ]
Device# show ip bgp neighbors 192.168.1.2
|
(Optional)
Displays information about the TCP and BGP connections to neighbors.
| Note
|
Only the
syntax applicable to this task is used in this example. For more details, see
the
Cisco IOS
IP Routing: BGP Command Reference.
|
|
| Step 15 |
show
ip
bgp
[network ]
[network-mask ]
|
(Optional)
Displays the entries in the BGP routing table.
| Note
|
Only the
syntax applicable to this task is used in this example. For more details, see
the
Cisco IOS
IP Routing: BGP Command Reference.
|
|
Examples
The following
partial output from the
show
ip
bgp
neighbors command shows information about the TCP
and BGP connections to the BGP neighbor 192.168.2.1. This peer supports route
refresh.
BGP neighbor is 192.168.1.2, remote AS 40000, external link
Neighbor capabilities:
Route refresh: advertised and received(new)
The following
partial output from the
show
ip
bgp
neighbors command shows information about the TCP
and BGP connections to the BGP neighbor 192.168.3.2. This peer does not support
route refresh so the soft-reconfig inbound paths for BGP peer 192.168.3.2 will
be stored because there is no other way to update any inbound policy updates.
BGP neighbor is 192.168.3.2, remote AS 50000, external link
Neighbor capabilities:
Route refresh: advertised
The following
sample output from the
show
ip
bgp command shows the entry for the network
172.17.1.0. Both BGP peers are advertising 172.17.1.0/24, but only the
received-only path is stored for 192.168.3.2.
BGP routing table entry for 172.17.1.0/24, version 11
Paths: (3 available, best #3, table Default-IP-Routing-Table, RIB-failure(4))
Flag: 0x820
Advertised to update-groups:
1
50000
192.168.3.2 from 192.168.3.2 (172.17.1.0)
Origin incomplete, metric 0, localpref 200, valid, external
50000, (received-only)
192.168.3.2 from 192.168.3.2 (172.17.1.0)
Origin incomplete, metric 0, localpref 100, valid, external
40000
192.168.1.2 from 192.168.1.2 (172.16.1.0)
Origin incomplete, metric 0, localpref 200, valid, external, best
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