Zte ZXR10 5900E Series Configuration Manual page 159

*>10.0.1.0/24
*>10.0.2.0/24
*>10.0.3.0/24
*>10.0.4.0/24
*>10.1.0.0/24
>10.1.0.0/24
ZXR10_AS500#show ip bgp route detail 10.1.0.0 255.255.255.0
BGP routing table entry for 10.1.0.0/24
01:19:50 received from 192.168.1.11 (10.0.2.1)
Origin ?, nexthop 192.168.1.13,
As path [400 100 100 100 100 100]
As4 path
Received label
AS 500 realizes that there are 6 ASs passing by the route from AS 400 to AS 100, and
3 ASs passing by the route if it is from AS 300 to AS 100. Therefore, BGP will select
the routing that passes the less ASs if other priorities are the default settings. That is,
the routing that is from AS 300 to AS 100 satisfies the configuration requirement.
l
Selecting Routes by Using LOCAL_PREF
Local_PREF is a well-known discretionary attribute. The default value is 100.
When a BGP router broadcasts routes to other BGP routers in the same AS, this
attribute shall be used. The value of attribute has influence on the path priority directly.
The route with the highest priority will be chosen as the optimum path. This attribute
also affects the local outbound traffic, and it is only used for local AS, that is, other
ASs will not affected by this attribute. Local-PREF is only exchanged between IBGP
neighbors, and it will not be advertised to EBGP neighbors.
Step
1
2
3
SJ-20150114102049-003|2015-01-15 (R1.0)
192.168.1.17
192.168.1.17
192.168.1.17
192.168.1.17
192.168.1.17
192.168.1.13
notag
Command
route-map <map-tag>[permit |
ZXR10(config)#
deny][<sequence-number>]
ipv4-access-list { name <acl-name>}
ZXR10(config)#
ZXR10(config-ipv4-acl)#
deny}{<source>[<source-wildcard>]| any}
route-map <map-tag>[permit |
ZXR10(config)#
deny][<sequence-number>]
ZXR10(config-route-map)#
<value>
20 300 200 100 i
20 300 200 100 400 i
20 300 200 i
0 300 i
20 300 200 100 i
20 400 100 100 100 100 100 i
rule <rule-no >{permit |
set local-preference
5-35
ZTE Proprietary and Confidential
Chapter 5 BGP Configuration
Function
This defines a route-map.
This enters standard ACL
configuration mode and
specifies ACL sequence
number, name or alias.
This defines the rule of
standard ACL.
This enters route mapping
configuration mode.
This specifies priority value
for AS. 0-4294967295, and
the default value is 100.