ensp-BGP

BGP:边界网关路由协议：boder gateway protocol

特点：

① 属于外部网关路由协议
② 针对大型网络、大型跨国集团、运营商、国与国之间的路由

路由协议分类

内部网关路由协议IGP：rip ospf isis （eigrp） 外部网关路由协议EGP：EGP（早期淘汰）BGP

BGP 邻居关系：

IBGP ：相同的AS路由器邻居
EBGP：不同AS的路由器邻居
注：EBGP 建邻居用直连接口 IBGP 建邻居用环回接口

bgp 路由传递：

BGP next-hop 属性

BGP 是以AS为个体，路由传递给其EBGP对等体时，下一跳会不变的引入AS的内部。 可能会引起下一跳不可达问题

解决：
R2:

bgp 200 peer 3.3.3.3 next-hop-local

路由传递给邻居3.3.3.3时将 路由的下一跳改为自己（2.2.2.2） 202 IBGP 水平分割属性：为了防止IBGP环路，默认情况下从IBGP对等体收到的路由不会传给其IBGP邻居。

解决水平分割：配置路由反射器 R3：

 bgp 200 peer 4.4.4.4 reflect-client  #
 将R4配置为自己的路由反射客户 端

注：从客户端（路由反射客户端）学到的路由可以无条件传递给任何对等体。

全网互通、路由引入、BGP 的路由汇总

BGP AS-path 属性

EBGP 防环：As-path 属性
IBGP 防环：ibgp 水平分割

路由聚合的AS-set 参数

注:一台路由器上面只能运行一个bgp 的进程。

详细命令

AR1

#
 sysname AR1
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
router id 1.1.1.1 
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 12.1.1.1 255.255.255.0 
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
 ip address 1.1.1.1 255.255.255.0 
#
interface LoopBack1
 ip address 1.1.2.1 255.255.255.0 
#
interface LoopBack2
 ip address 1.1.3.1 255.255.255.0 
#
bgp 100
 peer 12.1.1.2 as-number 200 
 #
 ipv4-family unicast
  undo synchronization
  aggregate 1.1.0.0 255.255.252.0 detail-suppressed 
  network 1.1.1.0 255.255.255.0 
  network 1.1.2.0 255.255.255.0 
  network 1.1.3.0 255.255.255.0 
  network 12.1.1.0 255.255.255.0 
  peer 12.1.1.2 enable
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

AR2

#
 sysname AR2
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
router id 2.2.2.2 
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 12.1.1.2 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 23.1.1.2 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
 ip address 2.2.2.2 255.255.255.0 
#
bgp 200
 peer 3.3.3.3 as-number 200 
 peer 3.3.3.3 connect-interface LoopBack0
 peer 12.1.1.1 as-number 100 
 #
 ipv4-family unicast
  undo synchronization
  network 12.1.1.0 255.255.255.0 
  import-route ospf 1
  peer 3.3.3.3 enable
  peer 3.3.3.3 next-hop-local 
  peer 12.1.1.1 enable
#
ospf 1 
 area 0.0.0.0 
  network 2.2.2.0 0.0.0.255 
  network 23.1.1.0 0.0.0.255 
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

AR3

#
 sysname AR3
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
router id 3.3.3.3 
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 23.1.1.3 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 34.1.1.3 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
 ip address 3.3.3.3 255.255.255.0 
#
bgp 200
 peer 2.2.2.2 as-number 200 
 peer 2.2.2.2 connect-interface LoopBack0
 peer 4.4.4.4 as-number 200 
 peer 4.4.4.4 connect-interface LoopBack0
 #
 ipv4-family unicast
  undo synchronization
  peer 2.2.2.2 enable
  peer 4.4.4.4 enable
  peer 4.4.4.4 reflect-client
#
ospf 1 
 area 0.0.0.0 
  network 3.3.3.0 0.0.0.255 
  network 23.1.1.0 0.0.0.255 
  network 34.1.1.0 0.0.0.255 
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

AR4

#
 sysname AR4
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
router id 4.4.4.4 
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 34.1.1.4 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 45.1.1.4 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
 ip address 4.4.4.4 255.255.255.0 
#
bgp 200
 peer 3.3.3.3 as-number 200 
 peer 3.3.3.3 connect-interface LoopBack0
 peer 45.1.1.5 as-number 300 
 #
 ipv4-family unicast
  undo synchronization
  aggregate 1.1.0.0 255.255.252.0 as-set detail-suppressed 
  network 45.1.1.0 255.255.255.0 
  peer 3.3.3.3 enable
  peer 45.1.1.5 enable
#
ospf 1 
 area 0.0.0.0 
  network 4.4.4.0 0.0.0.255 
  network 34.1.1.0 0.0.0.255 
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

AR5

#
 sysname AR5
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
router id 5.5.5.5 
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 45.1.1.5 255.255.255.0 
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
 ip address 5.5.5.5 255.255.255.0 
#
bgp 300
 peer 45.1.1.4 as-number 200 
 #
 ipv4-family unicast
  undo synchronization
  network 5.5.5.0 255.255.255.0 
  network 45.1.1.0 255.255.255.0 
  peer 45.1.1.4 enable
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return