BGP routing table entry information of 172.16.1.0/24:
From: 10.1.3.2 (10.1.5.1)
Route Duration: 00h10m21s
Direct Out-interface: GigabitEthernet0/0/0
Original nexthop: 10.1.3.2
Qos information : 0x0
AS-path 65002 65004 65005, origin incomplete, pref-val 0, valid, external,
select
, active, pre 255,
not preferred for router ID
Not advertised to any peer yet
The preceding command output shows that the route learned from Router B is optimal and is
used along with the route learned from Router C (not optimal) for load balancing. Check the
information about the route 172.16.1.0/24 in the IP routing table.
[RouterA]
display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 9 Routes : 12
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/30 Direct 0 0 D 10.1.1.1
GigabitEthernet0/0/1
10.1.1.1/32 Direct 0 0 D 127.0.0.1
GigabitEthernet0/0/1
10.1.3.0/30 Direct 0 0 D 10.1.3.1
GigabitEthernet0/0/0
10.1.3.1/32 Direct 0 0 D 127.0.0.1
GigabitEthernet0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
172.16.1.0/24 EBGP 255 0 D 10.1.1.2
GigabitEthernet0/0/1
EBGP 255 0 D 10.1.3.2
GigabitEthernet0/0/0
172.16.2.0/24 EBGP 255 0 D 10.1.1.2
GigabitEthernet0/0/1
EBGP 255 0 D 10.1.3.2
GigabitEthernet0/0/0
172.16.3.0/24 EBGP 255 0 D 10.1.1.2
GigabitEthernet0/0/1
EBGP 255 0 D 10.1.3.2 GigabitEthernet0/0/0
The preceding command output shows that BGP has delivered the two routes with the same
route prefix to the IP routing table for load balancing.
Clearing the AS_Path
When the
apply as-path
command is configured, if
none
overwrite
is specified in the command,
the device clears the AS_Path to hide the actual path information. If the AS_Path is null, BGP
considers its length as 0 during route selection.
Origin
The Origin attribute indicates how routes become BGP routes.
Three types of Origin attributes are available:
l
IGP
: indicates that routes are added to the BGP routing table using the
network
command.
IGP
has the highest priority.
l
EGP
: indicates that routes are learned through the EGP protocol.
EGP
has the second
highest priority.
HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
8 BGP Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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