简介
本文档介绍在使用边界网关协议(BGP)路由和源地点(SoO)时,如何避免SD-WAN交换矩阵中的路由环路。
先决条件
要求
Cisco 建议您了解以下主题:
- 对重叠管理协议(OMP)的基本了解
- 对BGP的基本了解
- SD-WAN组件及其之间的交互
使用的组件
本文档中的信息基于以下软件和硬件版本:
- 3台软件版本17.2.1v的Cisco IOS® XE CSR1000v路由器,在控制器模式(SD-WAN)下运行
- 2台软件版本为16.7.3的Cisco IOS XE CSR1000v路由器
本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始(默认)配置。如果您的网络处于活动状态,请确保您了解所有命令的潜在影响。
背景信息
在本文档中,使用的是以下拓扑:
拓扑
R1和R2是通用的Cisco IOS XE路由器(或能够运行BGPv4的任何其他路由器)。cE1、cE2和cE3在控制器(SD-WAN)模式下运行Cisco IOS XE。您可以在此处找到分配给每个SD-WAN路由器的站点ID和system-ip参数的摘要:
SD-WAN路由器
|
站点ID
|
system-ip
|
cE1 |
214 |
192.168.30.214 |
cE2 |
215 |
192.168.30.215 |
cE3 |
216 |
192.168.30.216 |
以下是最初发生的一组事件:
- R1和R2与cE1、cE2和cE3建立相应的eBGP对等。cE1和cE2建立iBGP对等。
- R2生成BGP路由10.1.1.0/24,并通过eBGP将其通告给cE3。
- cE3在VRF 1地址系列的服务端接收此BGP路由,然后将此路由重分配到OMP。
- cE3将10.1.1.0/24 OMP路由通告给SD-WAN重叠(vSmart控制器负责通过OMP协议将路由信息传播给加入SD-WAN重叠的所有其他边缘路由器)。
- cE1和cE2接收OMP路由,并通过VRF 1中的eBGP将其重新分发回R1。
配置
以下是cE1的相关配置。请注send-comminity
意,没有为邻居192.168.160.215配置:
router bgp 65401
bgp log-neighbor-changes
distance bgp 20 200 20
!
address-family ipv4 vrf 1
redistribute omp
propagate-aspath
neighbor 192.168.140.10 remote-as 65300
neighbor 192.168.140.10 activate
neighbor 192.168.140.10 send-community both
neighbor 192.168.160.215 remote-as 65400
neighbor 192.168.160.215 activate
exit-address-family
!
sdwan
omp
no shutdown
send-path-limit 4
ecmp-limit 4
graceful-restart
no as-dot-notation
timers
holdtime 60
advertisement-interval 1
graceful-restart-timer 43200
eor-timer 300
exit
address-family ipv4 vrf 1
advertise bgp
!
address-family ipv4
advertise connected
advertise static
!
address-family ipv6
advertise connected
advertise static
cE2:
router bgp 65401
bgp log-neighbor-changes
distance bgp 20 200 20
!
address-family ipv4 vrf 1
redistribute omp
propagate-aspath
neighbor 192.168.150.10 remote-as 65300
neighbor 192.168.150.10 activate
neighbor 192.168.150.10 send-community both
neighbor 192.168.160.214 remote-as 65401
neighbor 192.168.160.214 activate
neighbor 192.168.160.214 send-community both
exit-address-family
!
sdwan
omp
no shutdown
send-path-limit 4
ecmp-limit 4
graceful-restart
no as-dot-notation
timers
holdtime 60
advertisement-interval 1
graceful-restart-timer 43200
eor-timer 300
exit
address-family ipv4 vrf 1
advertise bgp
!
address-family ipv4
advertise connected
advertise static
!
address-family ipv6
advertise connected
advertise static
cE3:
router bgp 65401
bgp log-neighbor-changes
timers bgp 5 15
!
address-family ipv4 vrf 1
redistribute omp
propagate-aspath
neighbor 192.168.60.11 remote-as 65500
neighbor 192.168.60.11 activate
exit-address-family
!
sdwan
omp
no shutdown
send-path-limit 4
ecmp-limit 4
graceful-restart
no as-dot-notation
timers
holdtime 60
advertisement-interval 1
graceful-restart-timer 43200
eor-timer 300
exit
address-family ipv4 vrf 1
advertise bgp
!
address-family ipv4
advertise connected
advertise static
!
address-family ipv6
advertise connected
advertise static
!
验证
1.在初始状态下,路由从cE3通告并通过OMP由cE1和cE2获取。将路由重分发到BGP,并通告给彼此和R1:
cE1#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 342041
Paths: (2 available, best #2, table 1)
Advertised to update-groups:
4 5
Refresh Epoch 1
65500
192.168.160.215 (via vrf 1) from 192.168.160.215 (192.168.109.215)
Origin incomplete, metric 1000, localpref 50, valid, internal
Extended Community: SoO:0:215 RT:1:1
rx pathid: 0, tx pathid: 0
Updated on Aug 21 2020 11:23:32 GMT
Refresh Epoch 1
65500
192.168.30.216 (via default) from 0.0.0.0 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:214 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 11:23:32 GMT
cE2#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 327810
Paths: (2 available, best #2, table 1)
Advertised to update-groups:
5 6
Refresh Epoch 1
65500
192.168.160.214 (via vrf 1) from 192.168.160.214 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, internal
Extended Community: RT:1:1
rx pathid: 0, tx pathid: 0
Updated on Aug 21 2020 11:23:32 GMT
Refresh Epoch 1
65500
192.168.30.216 (via default) from 0.0.0.0 (192.168.109.215)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:215 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 11:23:32 GMT
2.在cE2上,WAN接口断开连接或与SD-WAN交换矩阵的连接丢失,因此OMP对等体(vSmart连接)关闭。只有一条路由仍然从iBGP获知:
ce2(config)#
interface GigabitEthernet 2
ce2(config-if)#
shutdown
ce2(config-if)#
end
Uncommitted changes found, commit them? [yes/no/CANCEL] yes
Commit complete.
ce2#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 345276
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
6
Refresh Epoch 1
65500
192.168.160.214 (via vrf 1) from 192.168.160.214 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, internal, best
Extended Community: RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 11:23:32 GMT
cE1 still prefers the route via OMP (this is the only route that remains) originated by cE3:
ce1#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 342041
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
4 5
Refresh Epoch 1
65500
192.168.30.216 (via default) from 0.0.0.0 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:214 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 11:23:32 GMT
3.在cE2的WAN接口上重新建立连接。由于管理距离(AD)更好,因此仍首选通过iBGP从cE1获取路由。
ce2(config)#
interface GigabitEthernet 2
ce2(config-if)#
no shutdown
ce2(config-if)#
end
Uncommitted changes found, commit them? [yes/no/CANCEL] yes
Commit complete.
ce2#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 345276
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
6
Refresh Epoch 1
65500
192.168.160.214 (via vrf 1) from 192.168.160.214 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, internal, best
Extended Community: RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 11:23:32 GMT
cE1仍首选通过cE3发起的OMP的路由。请记住,cE1将OMP重分发到BGP:
ce1#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 569358
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
4 5
Refresh Epoch 1
65500
192.168.30.216 (via default) from 0.0.0.0 (192.168.109.214)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:214 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 15:13:09 GMT
4.cE3与R2的连接发生问题。要测试,接口已关闭,R2 BGP对等体丢失:
ce3(config)#
interface GigabitEthernet 6
ce3(config-if)#
shutdown
ce3(config-if)#
commit
5.因此,在cE1和cE2之间形成了路由环路(cE2将来自OMP的路由重分布并通过BGP通告给cE1,cE1将BGP重分布到OMP并通告给cE2):
ce1#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 732548
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
5
Refresh Epoch 1
65500
192.168.160.215 (via vrf 1) from 192.168.160.215 (192.168.109.215)
Origin incomplete, metric 1000, localpref 50, valid, internal, best
Extended Community: SoO:0:215 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Aug 21 2020 15:38:47 GMT
ce2#
show bgp vpnv4 unicast vrf 1 10.1.1.1/24
BGP routing table entry for 1:1:10.1.1.1/24, version 639650
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
5 6
Refresh Epoch 1
65500
192.168.30.214 (via default) from 0.0.0.0 (192.168.109.215)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:215 RT:1:1
rx pathid: 1, tx pathid: 0x0
Updated on Aug 21 2020 15:38:47 GMT
故障排除
有两种可能的解决方案。
解决方案 1
为OMP配置overlay-as。然后,将一些自治系统(AS)编号分配给OMP重叠本身。例如:
config-transaction
sdwan
omp
overlay-as 64512
exit
默认情况下,OMP对BGP是透明的,即使propagate-aspath
已配置。overlay-as
是一项将指定为此命令参数的AS预置到从OMP导出到BGP的路由的BGP AS_PATH属性的功能。如果在重叠网络中的多个设备上配置相同的重叠AS编号,则所有这些设备都被视为同一AS的一部分。因此,它们不会转发包含重叠AS编号的任何路由,因此可以防止路由环路。
请记住,overlay-as
和propagate-aspath
是相互依赖的。此功能将详细讨论。
存在两个案例。
Overlay-AS案例1
overlay-as
配置在全局级别的sdwan omp
部分,propagate-aspath
但未配置(rest配置与最初所述的配置相同:advertise bgp
在“部分”下omp address-family ipv4 vrf 1
启用,redistribute omp
在“部分”router bgp address-family ipv4 vrf 1
下配置。
overlay-as 64512
在cE1/cE2和cE3上配置。
重叠即示演示的拓扑
出于演示目的,cE1、cE2和cE3上的BGP AS已更改。
R1 - cE1/cE2仍通过eBGP对等,分别使用AS65300和65401。
cE3 - R2仍然通过eBGP对等,AS 65402和65500分别使用。
R1将路由(例如192.168.41.11/32)发送到cE1/cE2。cE1/cE2将此路由重分发到OMP,不带有任何AS_PATH属性。
cE3收到它并将其通告到BGP中指向R2,仅具有其自己的AS(正常的eBGP行为)。
R2上的路由route1具有AS_PATH:65402.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 ?
Overlay-AS案例2
propagate-aspath
在部分router
bgp
下为特定服务端VPN(address-family ipv4 vrf 1
)配置。 这里也有子案例。
案例2.1.在overlay-as
cE3上启用后,propagate-aspath
在cE1/router bgp 65401 address-family ipv4 vrf 1
cE2上也启用了。
R1将路由route1发送到cE1/cE2。cE1/cE2使用来自R1站点的as-path将此路由重分发到OMP。
vSmart上的OMP路由具有AS路径:65300.
vsmart1#
show omp routes vpn 1 192.168.41.11/32 | nomore | exclude not\ set
---------------------------------------------------
omp route entries for vpn 1 route 192.168.41.11/32
---------------------------------------------------
RECEIVED FROM:
peer 192.168.30.214
path-id 81
label 1001
status C,R
Attributes:
originator 192.168.30.214
type installed
tloc 192.168.30.214, biz-internet, ipsec
overlay-id 1
site-id 25
origin-proto eBGP
origin-metric 0
as-path "65300"
RECEIVED FROM:
peer 192.168.30.215
path-id 68
label 1002
status C,R
Attributes:
originator 192.168.30.215
type installed
tloc 192.168.30.215, biz-internet, ipsec
overlay-id 1
site-id 25
origin-proto eBGP
origin-metric 0
as-path "65300"
案例2.1.a.在cE3上禁用propagate-aspath
后,cE3将其作为OMP路由接收并通告到BGP,忽略任何as-path属性,在R2上重叠as,并仅添加其自己的BGP AS(正常eBGP行为)。
R2 AS路径上的路由route1:65402.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 ?
案例2.1.b.在cE3上启用propagate-aspath
后,cE3会将其作为OMP路由接收并将其通告到BGP,将接收的as-path属性预置到R2,然后添加重叠AS,接着添加自己的BGP AS。
R2 AS路径上的路由route1:65402 64512 65300.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 64512 65300 ?
案例2.1.c.在propagate-aspath
cE1/cE2上禁用后,cE3将其作为OMP路由接收,而无任何as-path属性,并将它通告到BGP中,指向R2,预置Overlay-AS并仅添加其自己的BGP AS。
R2 AS路径上的路由route1:6540264512.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 64512 ?
案例2.2.在cEoverlay-as
3上未配置,propagate-aspath
在cE1/cE2上的router bgp 65401 address-family ipv4 vrf 1下启用。
案例2.2.a.仅propagate-aspath
在cE3上禁用时,cE3将其作为OMP路由接收并通告到BGP,忽略任何AS_PATH属性,指向R2,添加其自己的BGP AS(正常eBGP行为)。
R2 AS路径上的路由route1:65402.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 ?
案例2.2.b.当propagate-aspath
在cE3上启用时,cE3会将其作为OMP路由接收并将其通告到BGP,将收到的AS_PATH属性预置到R2上,然后添加自己的AS。
R2 AS路径上的路由route1:6540265300.
R2#
sh ip bgp | i 192.168.41.11/32
*> 192.168.41.11/32 192.168.60.216 1000 0 65402 65300 ?
注意:当您将AS-Path属性发送到OMP时,边缘路由器不会添加自己的AS(如vEdge Does Advertise Its Own AS When BGP Routes Are Advertised Into OMP一文所示)。 如果远程边缘路由器在AS_PATH属性中收到具有自己的AS的OMP路由,它不会执行环路检测,而是将具有所接收AS路径的路由发送到服务端的路由器。
解决方案 2
在路由器cE1和cE2上配置相同的site-id。虽然vSmart使用与路由本身相同的站点ID将路由通告回站点,但由于路由的发起方属性不同,因此不会触发环路预防,但不会形成控制平面路由环路,因为OMP路由未安装到RIB中。这是因为OMP路由处于Inv,U(无效,未解析)状态。默认情况下,除非配置了数据平面隧道,否则无法在具有相同站点ID的站点之allow-same-site-tunnels
间建立隧道。如果数据平面隧道BFD会话处于关闭状态,则TLOC保持未解析状态。在本例中,路由器ce1和ce2上均配置了site-id 214215
。由cE2和cE1通告的路由10.0.0.2/32不会将其安装到路由表中,因为cE1和cE2之间不存在数据平面会话:
ce1#
show sdwan omp route 10.0.0.2/32 det | exc not set
---------------------------------------------------
omp route entries for vpn 3 route 10.0.0.2/32
---------------------------------------------------
RECEIVED FROM:
peer 192.168.30.113
path-id 3
label 1004
status Inv,U
Attributes:
originator 192.168.30.215
type installed
tloc 192.168.30.215, mpls, ipsec
overlay-id 1
site-id 214215
origin-proto connected
origin-metric 0
RECEIVED FROM:
peer 192.168.30.113
path-id 4
label 1004
status Inv,U
loss-reason tloc-id
lost-to-peer 192.168.30.113
lost-to-path-id 3
Attributes:
originator 192.168.30.215
type installed
tloc 192.168.30.215, biz-internet, ipsec
overlay-id 1
site-id 214215
origin-proto connected
origin-metric 0
ce1#
show sdwan omp tlocs "ip 192.168.30.215" | exclude not set
---------------------------------------------------
tloc entries for 192.168.30.215
mpls
ipsec
---------------------------------------------------
RECEIVED FROM:
peer 192.168.30.113
status C,I,R
Attributes:
attribute-type installed
encap-proto 0
encap-spi 256
encap-auth sha1-hmac,ah-sha1-hmac
encap-encrypt aes256
public-ip 192.168.110.215
public-port 12347
private-ip 192.168.110.215
private-port 12347
public-ip ::
public-port 0
private-ip ::
private-port 0
bfd-status down
site-id 214215
preference 0
weight 1
version 3
gen-id 0x80000026
carrier default
restrict 0
groups [ 0 ]
bandwidth 0
qos-group default-group
---------------------------------------------------
tloc entries for 192.168.30.215
biz-internet
ipsec
---------------------------------------------------
RECEIVED FROM:
peer 192.168.30.113
status C,I,R
Attributes:
attribute-type installed
encap-proto 0
encap-spi 256
encap-auth sha1-hmac,ah-sha1-hmac
encap-encrypt aes256
public-ip 192.168.109.215
public-port 12347
private-ip 192.168.109.215
private-port 12347
public-ip ::
public-port 0
private-ip ::
private-port 0
bfd-status down
site-id 214215
preference 0
weight 1
version 3
gen-id 0x80000026
carrier default
restrict 0
groups [ 0 ]
bandwidth 0
qos-group default-group
ce1#
您可以在vSmart控制器上检查此命令,以便了解哪些路由接收特定前缀(请参阅“通告给”部分):
vsmart1#
show omp routes 10.1.1.0/24 detail | nomore | exclude not\ set
---------------------------------------------------
omp route entries for vpn 1 route 10.1.1.0/24
---------------------------------------------------
RECEIVED FROM:
peer 192.168.30.216
path-id 68
label 1002
status C,R
Attributes:
originator 192.168.30.216
type installed
tloc 192.168.30.216, biz-internet, ipsec
overlay-id 1
site-id 216
origin-proto eBGP
origin-metric 0
as-path 65500
ADVERTISED TO:
peer 192.168.30.214
Attributes:
originator 192.168.30.216
label 1002
path-id 5525
tloc 192.168.30.216, biz-internet, ipsec
site-id 216
overlay-id 1
origin-proto eBGP
origin-metric 0
as-path 65500
ADVERTISED TO:
peer 192.168.30.215
Attributes:
originator 192.168.30.216
label 1002
path-id 5287
tloc 192.168.30.216, biz-internet, ipsec
site-id 216
overlay-id 1
origin-proto eBGP
origin-metric 0
as-path 65500
site-id
还保留为BGP源站点(SoO)扩展社区属性(您可以在前面的输出中看到SoO:0:<site-id>)。 用于标识源自站点的路由,以便可以阻止重新通告该前缀。为了使此功能正常运行,路由器必须发送扩展社区。配置cE1,将扩展团体发送到路由器cE2:
router bgp 65401
address-family ipv4 vrf 1
neighbor 192.168.160.215 send-community both
SoO环路预防说明
对于同一站点的两台路由器是iBGP邻居的情况,SD-WAN具有内置的环路预防机制,以防止路由环路从OMP到BGP以及从BGP返回OMP。为了演示这一点,拓扑稍作更新,并且在运行BGP AS65400(cE1/cE2)的两个路由器上配置了相同的site-id 214215。 在本示例中,10.1.1.0/24前缀从远程站点(cE3)通告到OMP,并在站点214215(cE1-cE2)的OMP中获知。
SoO演示的拓扑
为了实现环路防御,BGP扩展社区SoO用于显示哪个站点发起前缀。当此社区从OMP重分发到BGP时,会将其添加到前缀。
如所send-community
示,必须在两台设备中的neighbor语句上配置命令,以便此功能正常工作。
cEdge1#
show run | sec router bgp
router bgp 65400
bgp log-neighbor-changes
!
address-family ipv4 vrf 1
redistribute omp
neighbor 192.168.160.215 remote-as 65400
neighbor 192.168.160.215 activate
neighbor 192.168.160.215 send-community both
exit-address-family
cEdge2#
show run | sec router bgp
router bgp 65400
bgp log-neighbor-changes
!
address-family ipv4 vrf 1
neighbor 192.168.160.214 remote-as 65400
neighbor 192.168.160.214 activate
neighbor 192.168.160.214 send-community both
exit-address-family
从广告或接收站点的输出中show bgp vpnv4 unicast vrf 1
可以看到扩展社区。
示例
cEdge1#
show bgp vpnv4 unicast vrf 1 10.1.1.1
BGP routing table entry for 1:10:10.1.1.1/24, version 4
Paths: (1 available, best #1, table 1)
Advertised to update-groups:
1
Refresh Epoch 1
Local
192.168.30.215 (via default) from 0.0.0.0 (192.168.109.215)
Origin incomplete, metric 1000, localpref 50, valid, sourced, best
Extended Community: SoO:0:214215 RT:1:1
rx pathid: 0, tx pathid: 0x0
Updated on Jul 5 2152 23:30:55 UTC
在将前缀从OMP通告到BGP的路由器上(本例中为cEdge1),RIB中必须仅有OMP路由。
示例
cEdge1#
show ip route vrf 1 10.1.1.1
Routing Table: 1
Routing entry for 10.1.1.1/32
Known via "omp", distance 251, metric 0, type omp
Redistributing via bgp 65400
Advertised by bgp 65400
Last update from 192.168.30.215 on Sdwan-system-intf, 15:59:54 ago
Routing Descriptor Blocks:
* 192.168.30.215 (default), from 192.168.30.215, 15:59:54 ago, via Sdwan-system-intf
Route metric is 0, traffic share count is 1
但是,可能会发生争用情况发生在接收通告前缀的第二个路由器上,并且导致BGP路由在获知OMP路由之前安装到RIB中。
在cEdge2上,sh bpg vpnv4 unicast vrf 1 <prefix> 的输出显示以下内容:
- 未通告给任何对等体。
- 扩展社区包括站点ID214215站,此路由器位于同一站点。
示例
cEdge2#
show bgp vpnv4 unicast vrf 1 10.1.1.1
BGP routing table entry for 1:1:10.1.1.1/24, version 32
Paths: (1 available, best #1, table 1)
Not advertised to any peer
Refresh Epoch 1
Local
192.168.160.214 (via vrf 1) from 192.168.160.214 (192.168.54.11)
Origin incomplete, metric 1000, localpref 50, valid, internal, best
Extended Community: SoO:0:214215 RT:65512:10
rx pathid: 0, tx pathid: 0x0
Updated on Jul 6 2152 17:26:19 UTC
在cEdge2上,的输出显sh ip route vrf
示如下:
- 可以看到“SDWAN Down”标志,表明检测到该地址来自同一站点。
- 路由的管理距离为252(高于OMP并且不同于预期的iBGP AD 200)。
示例
cEdge2#
show ip route vrf 1 10.1.1.1
Routing Table: 1
Routing entry for 10.1.1.0/24
Known via "bgp 65400",
distance 252
, metric 1000, type internal
Redistributing via omp
Last update from 192.168.160.214 00:15:13 ago
Routing Descriptor Blocks:
* 192.168.160.214, from 192.168.160.214, 00:15:13 ago
opaque_ptr 0x7F9DD0B86818
SDWAN Down
Route metric is 1000, traffic share count is 1
AS Hops 0
MPLS label: none
当站点路由器检测到BGP获知的路由来自同一站点ID时,该路由不会通告回OMP。
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