1、为确保BGP路由争取加入到全局路由表中，首先需要确保BGP路由有效，其次要确保能够在和通过其他路由协议学到的路由比较中优选。
2、查看BGP 邻居状态
2.1 如果没有BGP路由表中，未能查询到相匹配的路由信息，需要查看BGP邻居状态是否正常
# 查看对等体的信息。
<Huawei> display bgp peer
Status codes: * - Dynamic
BGP Local router ID : 10.2.3.4
local AS number : 10
Total number of peers : 2
Peers in established state : 1
Total number of dynamic peers : 1
Peer V AS MsgRcvd MsgSent OutQ Up/Down State PrefRcv
10.1.1.1 4 100 0 0 0 00:00:07 Idle 0
10.2.5.6 4 200 32 35 0 00:17:49 Established 02.2 查看路由表，确认BGP邻居是否可达，查看邻居配置是否正确
# 显示当前路由表的概要信息，查看BGP邻居的IP地址是否存在匹配的路由。
<Huawei> display ip routing-table
Route Flags:
R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 8 Routes : 9
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.1/32 Static 60 0 D 0.0.0.0 NULL0
Static 60 0 D 192.168.0.2 GigabitEthernet1/0/0
192.168.0.0/24 Direct 0 0 D 192.168.0.1 GigabitEthernet1/0/0
192.168.0.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet1/0/0
192.168.0.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet1/0/0
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
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack02.3 查看BGP邻居配置是否正确
<Huawei> display current-configuration | include BGP
BGP 65520
undo synchronization
peer6.6.6.6 as-number 655202.4 查看BGP路由是否存在，主要是确认BGP路由表中是否存在相关路由
# 查看BGP的所有路由信息。
<Huawei> display bgp routing-table
BGP Local router ID is 10.1.1.2
Status codes: * - valid, > - best, d - damped, h - history,
i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 4
Network NextHop MED LocPrf PrefVal Path/Ogn
* 10.1.1.0/24 10.1.1.1 0 0 100?
* 10.1.1.2/32 10.1.1.1 0 0 100?
*> 10.1.1.0/24 10.1.1.1 0 0 100?
*> 10.1.1.0/24 10.1.1.1 0 0 100?2.5 如果BGP路由表中未有相关路由，需要确认BGP邻居是否将相关路由发送出来，华为默认是发不出来的，所以需要看没有发布的路由。
<Huawei> display bgp routing-table peer 1.1.1.1 no-advertise 3.3.3.4 32
BGP routing table entry information of 3.3.3.4/32:
From: 1.1.1.1 (10.1.1.1)
Route Duration: 22h36m17s
Relay IP Nexthop: 10.1.1.1
Relay IP Out-Interface: GigabitEthernet1/0/0
Original nexthop: 1.1.1.1
Qos information : 0x0
AS-path Nil, origin incomplete, MED 0, localpref 100, pref-val 0, valid, internal, best, select, active, pre 255, IGP cost 1
No advertise without config reflect-client2.6 查看BGP路由表信息，确认BGP路由表中相关路由是否有效
# 查看BGP的所有路由信息。
<Huawei> display bgp routing-table
BGP Local router ID is 10.1.1.2
Status codes: * - valid, > - best, d - damped, h - history,
i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 4
Network NextHop MED LocPrf PrefVal Path/Ogn
* 10.1.1.0/24 10.1.1.1 0 0 100?
* 10.1.1.2/32 10.1.1.1 0 0 100?
*> 10.1.1.0/24 10.1.1.1 0 0 100?
*> 10.1.1.0/24 10.1.1.1 0 0 100?2.7 确认BGP路由的下一跳是否存在匹配的路由
# 显示当前路由表的概要信息，查看BGP邻居的IP地址是否存在匹配的路由。
<Huawei> display ip routing-table
Route Flags:
R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 8 Routes : 9
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.1/32 Static 60 0 D 0.0.0.0 NULL0
Static 60 0 D 192.168.0.2 GigabitEthernet1/0/0
192.168.0.0/24 Direct 0 0 D 192.168.0.1 GigabitEthernet1/0/0
192.168.0.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet1/0/0
192.168.0.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet1/0/0
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
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack02.8 查看路由表中，BGP路由是否被选中，或者说相关路由是否有BGP学习到的。
# 显示当前路由表的概要信息，查看BGP邻居的IP地址是否存在匹配的路由。
<Huawei> display ip routing-table 10.1.1.2/32
Route Flags:
R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 1 Routes : 1
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.2/32 OSPF 60 0 D 10.1.1.1 S1/1/02.9 查看路由配置信息，确认在路由表中选中的路由所属的路由协议的优先级
<Huawei> display current-configuration | include ospf
ospf 10 router-id 3.3.3.3
prefernce ase 190
area 0.0.0.0
network 10.10.10.220 0.0.0.255
-----------------------------------------------------
<Huawei> display current-configuration | include bgp
bgp 65520
router-id 2.2.2.2
prefernce 170 170 170
network 10.10.20.220 0.0.0.2552.10 查看BGP属性，确认BGP是否优选到正确的路由
# 查看指定无效的BGP路由的详细信息。
<Huawei> display bgp routing-table 1.1.1.1
BGP local router ID : 10.1.1.1
Local AS number : 100
Paths: 2 available, 0 best, 0 select
BGP routing table entry information of 1.1.1.1/32:
From: 10.1.1.2 (10.1.1.2)
Route Duration: 00h01m31s
Relay IP Nexthop: 0.0.0.0
Relay IP Out-Interface:
Original nexthop: 20.1.1.2
Qos information : 0x0
AS-path 200, origin incomplete, MED 0, localpref 100, pref-val 0, internal, pre 255, invalid for IP unreachable
Not advertised to any peer yet
BGP routing table entry information of 1.1.1.1/32:
From: 2.2.2.2 (10.1.1.2)
Route Duration: 00h00m51s
Relay IP Nexthop: 0.0.0.0
Relay IP Out-Interface:
Original nexthop: 20.1.1.2
Qos information : 0x0
AS-path 200, origin incomplete, MED 0, localpref 100, pref-val 0, internal, pre 255, invalid for IP unreachable
Not advertised to any peer yet3、小结
3.1、首先先查邻居状态，在查BGP路由表，查看路由是否存在，是否有效，是否优先，最后查看BGP的属性；最后在查看是否优选了正确的路由
3.2 常用BGP属性比较顺序：1、比较Locprf属性大小，2、比较AS-Path的长短，3、比较Origin属性，i由于？，4、比较MED属性大小，5、优先选择从EBGP邻居学来的路由
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