配置BGP联盟示例-优快云博客

本文链接：https://blog.youkuaiyun.com/wangx_yu533/article/details/148998746

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BGP联盟可解决网络中过多的IBGP连接。

组网需求

某运营商在一个区域内拥有多台设备，现要求在该区域内实现IBGP全连接，如果采用每两台设备间配置IBGP连接的方式，则会由于设备数量较多导致IBGP连接数量过多，这样将产生较高的运维成本。为了解决这个问题，可以在该区域中部署BGP联盟功能。

如图1所示，为保证AS200内的各个设备之间的连通性，需要各个设备之间建立IBGP全连接关系。但是由于AS200中有多台运行BGP协议的NE，导致建立全连接网络的开销很大。此时为了减少IBGP的连接数量，可以在AS200内的设备上配置联盟功能。联盟是处理AS内部的IBGP网络连接激增的一种方法，以图1为例通过配置联盟功能将AS200划分为3个子自治系统：AS65001、AS65002和AS65003。AS65001通过配置联盟EBGP多等体关系与AS65002、AS65003建立连接，其中AS65001内的三台NE建立IBGP全连接关系。这样大量减少了AS200内的IBGP的连接数量，降低了运维成本。

图1 配置联盟组网图

本例中interface1，interface2，interface3，interface4，interface5分别代表GE0/1/0，GE0/2/0，GE0/3/0，GE0/1/1，GE0/1/2。

配置思路

采用如下的思路配置BGP联盟：

在AS200中各NE上配置BGP联盟。

在AS65001中配置IBGP连接。

在AS100和AS200之间配置EBGP连接，查看路由信息。

数据准备

为完成此配置例，需准备如下的数据：

DeviceA、DeviceB、DeviceC、DeviceD、DeviceE、DeviceF的Router ID分别为1.1.1.1、2.2.2.2、3.3.3.3、4.4.4.4、5.5.5.5、6.6.6.6。

自治系统号AS100，自治系统号AS200，AS200中的3个子自治系统号AS65001，AS65002，AS65003。

操作步骤

配置各接口的IP地址（略）
配置BGP联盟

# 配置DeviceA。

[~DeviceA] bgp 65001

[*DeviceA-bgp] router-id 1.1.1.1

[*DeviceA-bgp] confederation id 200

[*DeviceA-bgp] confederation peer-as 65002 65003

[*DeviceA-bgp] peer 10.1.1.2 as-number 65002

[*DeviceA-bgp] peer 10.1.2.2 as-number 65003

[*DeviceA-bgp] ipv4-family unicast

[*DeviceA-bgp-af-ipv4] peer 10.1.1.2 next-hop-local

[*DeviceA-bgp-af-ipv4] peer 10.1.2.2 next-hop-local

[*DeviceA-bgp-af-ipv4] commit

[~DeviceA-bgp-af-ipv4] quit

[~DeviceA-bgp] quit

# 配置DeviceB。

[~DeviceB] bgp 65002

[*DeviceB-bgp] router-id 2.2.2.2

[*DeviceB-bgp] confederation id 200

[*DeviceB-bgp] confederation peer-as 65001

[*DeviceB-bgp] peer 10.1.1.1 as-number 65001

[*DeviceB-bgp] commit

[~DeviceB-bgp] quit

# 配置DeviceC。

[~DeviceC] bgp 65003

[*DeviceC-bgp] router-id 3.3.3.3

[*DeviceC-bgp] confederation id 200

[*DeviceC-bgp] confederation peer-as 65001

[*DeviceC-bgp] peer 10.1.2.1 as-number 65001

[*DeviceC-bgp] commit

[~DeviceC-bgp] quit

配置AS65001内的IBGP连接

# 配置DeviceA。

[~DeviceA] bgp 65001

[*DeviceA-bgp] peer 10.1.3.2 as-number 65001

[*DeviceA-bgp] peer 10.1.4.2 as-number 65001

[*DeviceA-bgp] ipv4-family unicast

[*DeviceA-bgp-af-ipv4] peer 10.1.3.2 next-hop-local

[*DeviceA-bgp-af-ipv4] peer 10.1.4.2 next-hop-local

[*DeviceA-bgp-af-ipv4] commit

[~DeviceA-bgp-af-ipv4] quit

[~DeviceA-bgp] quit

# 配置DeviceD。

[~DeviceD] bgp 65001

[*DeviceD-bgp] router-id 4.4.4.4

[*DeviceD-bgp] confederation id 200

[*DeviceD-bgp] peer 10.1.3.1 as-number 65001

[*DeviceD-bgp] peer 10.1.5.2 as-number 65001

[*DeviceD-bgp] commit

[~DeviceD-bgp] quit

# 配置DeviceE。

[~DeviceE] bgp 65001

[*DeviceE-bgp] router-id 5.5.5.5

[*DeviceE-bgp] confederation id 200

[*DeviceE-bgp] peer 10.1.4.1 as-number 65001

[*DeviceE-bgp] peer 10.1.5.1 as-number 65001

[*DeviceE-bgp] commit

[~DeviceE-bgp] quit

配置AS100和AS200之间的EBGP连接

# 配置DeviceA。

[~DeviceA] bgp 65001

[*DeviceA-bgp] peer 10.216.1.2 as-number 100

[*DeviceA-bgp] commit

[~DeviceA-bgp] quit

# 配置DeviceF。

[~DeviceF] bgp 100

[*DeviceF-bgp] router-id 6.6.6.6

[*DeviceF-bgp] peer 10.216.1.1 as-number 200

[*DeviceF-bgp] ipv4-family unicast

[*DeviceF-bgp-af-ipv4] network 192.168.1.0 255.255.255.0

[*DeviceF-bgp-af-ipv4] commit

[~DeviceF-bgp-af-ipv4] quit

[~DeviceF-bgp] quit

查看配置结果

# 查看DeviceB的BGP路由表。

[~DeviceB] display bgp routing-table

BGP Local router ID is 2.2.2.2

Status codes: * - valid, > - best, d - damped, x - best external, a - add path,

h - history, i - internal, s - suppressed, S - Stale

Origin : i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V - valid, I - invalid, N - not-found

Total Number of Routes: 1

Network NextHop MED LocPrf PrefVal Path/Ogn

*>i 192.168.1.0/24 10.1.1.1 0 100 0 (65001) 100i

[~DeviceB] display bgp routing-table 192.168.1.0

BGP local router ID : 2.2.2.2

Local AS number : 65002

Paths: 1 available, 1 best, 1 select

BGP routing table entry information of 192.168.1.0/24:

From: 10.1.1.1 (1.1.1.1)

Route Duration: 00h12m29s

Relay IP Nexthop: 0.0.0.0

Relay IP Out-Interface: GigabitEthernet0/1/0

Original nexthop: 10.1.1.1

Qos information : 0x0

AS-path (65001) 100, origin igp, MED 0, localpref 100, pref-val 0, valid, external-confed, best, select, active, pre 255

Not advertised to any peer yet

# 查看DeviceD的BGP路由表。

[~DeviceD] display bgp routing-table

BGP Local router ID is 4.4.4.4

Status codes: * - valid, > - best, d - damped, x - best external, a - add path,

h - history, i - internal, s - suppressed, S - Stale

Origin : i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V - valid, I - invalid, N - not-found

Total Number of Routes: 1

Network NextHop MED LocPrf PrefVal Path/Ogn

*>i 192.168.1.0/24 10.1.3.1 0 100 0 100i

[~DeviceD] display bgp routing-table 192.168.1.0

BGP local router ID : 4.4.4.4

Local AS number : 65001

Paths: 1 available, 1 best, 1 select

BGP routing table entry information of 192.168.1.0/24:

From: 10.1.3.1 (1.1.1.1)

Route Duration: 00h23m57s

Relay IP Nexthop: 0.0.0.0

Relay IP Out-Interface: GigabitEthernet0/1/0

Original nexthop: 10.1.3.1

Qos information : 0x0

AS-path 100, origin igp, MED 0, localpref 100, pref-val 0, valid, internal-confed, best, select, active, pre 255

Not advertised to any peer yet

配置文件

DeviceA的配置文件

sysname DeviceA

interface GigabitEthernet0/1/0

undo shutdown

ip address 10.216.1.1 255.255.255.0

interface GigabitEthernet0/2/0

undo shutdown

ip address 10.1.1.1 255.255.255.0

interface GigabitEthernet0/3/0

undo shutdown

ip address 10.1.2.1 255.255.255.0

interface GigabitEthernet0/1/1

undo shutdown

ip address 10.1.3.1 255.255.255.0

interface GigabitEthernet0/1/2

undo shutdown

ip address 10.1.4.1 255.255.255.0

bgp 65001

router-id 1.1.1.1

confederation id 200

confederation peer-as 65002 65003

peer 10.1.1.2 as-number 65002

peer 10.1.2.2 as-number 65003

peer 10.1.3.2 as-number 65001

peer 10.1.4.2 as-number 65001

peer 10.216.1.2 as-number 100

ipv4-family unicast

undo synchronization

peer 10.216.1.2 enable

peer 10.1.1.2 enable

peer 10.1.1.2 next-hop-local

peer 10.1.2.2 enable

peer 10.1.2.2 next-hop-local

peer 10.1.3.2 enable

peer 10.1.3.2 next-hop-local

peer 10.1.4.2 enable

peer 10.1.4.2 next-hop-local

return

DeviceB的配置文件

sysname DeviceB

interface GigabitEthernet0/1/0

undo shutdown

ip address 10.1.1.2 255.255.255.0

bgp 65002

router-id 2.2.2.2

confederation id 200

confederation peer-as 65001

peer 10.1.1.1 as-number 65001

ipv4-family unicast

undo synchronization

peer 10.1.1.1 enable

return

DeviceC的配置文件与DeviceB类似，此处省略。

DeviceD的配置文件

sysname DeviceD

interface GigabitEthernet0/1/0

undo shutdown

ip address 10.1.3.2 255.255.255.0

interface GigabitEthernet0/2/0

undo shutdown

ip address 10.1.5.1 255.255.255.0

bgp 65001

router-id 4.4.4.4

confederation id 200

peer 10.1.3.1 as-number 65001

peer 10.1.5.2 as-number 65001

ipv4-family unicast

undo synchronization

peer 10.1.3.1 enable

peer 10.1.5.2 enable

return

DeviceE的配置文件与DeviceD类似，此处省略。

DeviceF的配置文件

sysname DeviceF

interface GigabitEthernet0/1/0

undo shutdown

ip address 10.216.1.2 255.255.255.0

interface GigabitEthernet0/2/0

undo shutdown

ip address 192.168.1.1 255.255.255.0

bgp 100

router-id 6.6.6.6

peer 10.216.1.1 as-number 200

ipv4-family unicast

undo synchronization

network 192.168.1.0 255.255.255.0

peer 10.216.1.1 enable

return