配置静态BFD for IS-IS特性示例
介绍静态BFD for IS-IS的配置过程,包括配置BFD参数和使能静态BFD。
组网需求
如图9-6所示。
DeviceA和DeviceB之间采用二层交换机相连。
DeviceA、DeviceB和DeviceC之间运行IS-IS。
使用BFD检测DeviceA和DeviceB的IS-IS邻居关系。当DeviceA和DeviceB之间的链路发生故障时,BFD能够快速检测到故障并通告给IS-IS协议。
设备名称 |
接口 |
IP地址 |
---|---|---|
DeviceA |
GE0/1/0 |
10.1.1.1/24 |
DeviceB |
GE0/1/0 |
10.1.1.2/24 |
GE0/2/0 |
10.2.1.1/24 |
|
DeviceC |
GE0/1/0 |
10.2.1.2/24 |
由于DeviceA和DeviceC之间不建立IS-IS邻居,所以BFD for IS-IS特性不能用于检测DeviceA到DeviceC的多跳链路。
数据准备
为完成此配置例,需准备如下的数据:
IS-IS协议进程号
DeviceA、DeviceB和DeviceC的区域地址。
DeviceA、DeviceB和DeviceC的级别。
DeviceA和DeviceB之间建立BFD的名称和BFD检测的对端IP地址。
DeviceA和DeviceB进行BFD对话的本地标识符和远端标识符。
操作步骤
- 配置各路由器接口的IP地址(略)
- 配置IS-IS基本功能
# 配置DeviceA。
[~DeviceA] isis 1
[*DeviceA-isis-1] is-level level-2
[*DeviceA-isis-1] network-entity aa.1111.1111.1111.00
[*DeviceA-isis-1] quit
[*DeviceA] interface gigabitethernet 0/1/0
[*DeviceA-GigabitEthernet0/1/0] isis enable 1
[*DeviceA-GigabitEthernet0/1/0] commit
[~DeviceA-GigabitEthernet0/1/0] quit
# 配置DeviceB。
[~DeviceB] isis 1
[*DeviceB-isis-1] is-level level-2
[*DeviceB-isis-1] network-entity aa.2222.2222.2222.00
[*DeviceB-isis-1] quit
[*DeviceB] interface gigabitethernet 0/1/0
[*DeviceB-GigabitEthernet0/1/0] isis enable 1
[*DeviceB-GigabitEthernet0/1/0] quit
[*DeviceB] interface gigabitethernet 0/2/0
[*DeviceB-GigabitEthernet0/2/0] isis enable 1
[*DeviceB-GigabitEthernet0/2/0] commit
[~DeviceB-GigabitEthernet0/2/0] quit
# 配置DeviceC。
[~DeviceC] isis 1
[*DeviceC-isis-1] is-level level-2
[*DeviceC-isis-1] network-entity aa.3333.3333.3333.00
[*DeviceC-isis-1] quit
[*DeviceC] interface gigabitethernet 0/1/0
[*DeviceC-GigabitEthernet0/1/0] isis enable 1
[*DeviceC-GigabitEthernet0/1/0] commit
[~DeviceC-GigabitEthernet0/1/0] quit
配置完成后,可以看到DeviceA与DeviceB建立了邻居关系。
[~DeviceA] display isis peer
Peer information for ISIS(1) System Id Interface Circuit Id State HoldTime Type PRI
---------------------------------------------------------------------------------
2222.2222.2222 GE0/1/0 2222.2222.2222.00 Up 23s L2 64
Total Peer(s): 1
DeviceA的IS-IS路由表中有去往DeviceB和DeviceC的表项。
[~DeviceA] display isis route
Route information for ISIS(1)
-----------------------------
ISIS(1) Level-2 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------
10.1.1.0/24 10 NULL GE0/1/0 Direct D/-/L/-
10.2.1.0/24 20 NULL GE0/1/0 10.1.1.2 A/-/-/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut, U-Up/Down Bit Set
- 配置BFD
# 在DeviceA上使能BFD,并配置BFD Session。
[~DeviceA] bfd
[*DeviceA-bfd] quit
[*DeviceA] bfd atob bind peer-ip 10.1.1.2 interface gigabitethernet0/1/0
[*DeviceA-bfd-session-atob] discriminator local 1
[*DeviceA-bfd-session-atob] discriminator remote 2
[*DeviceA-bfd-session-atob] commit
[~DeviceA-bfd-session-atob] quit
# 在DeviceB上使能BFD,并配置BFD Session。
[~DeviceB] bfd
[*DeviceB-bfd] quit
[*DeviceB] bfd btoa bind peer-ip 10.1.1.1 interface gigabitethernet0/1/0
[*DeviceB-bfd-session-btoa] discriminator local 2
[*DeviceB-bfd-session-btoa] discriminator remote 1
[*DeviceB-bfd-session-btoa] commit
[~DeviceB-bfd-session-btoa] quit
配置完成后,在DeviceA或DeviceB上执行display bfd session命令,可以看到BFD Session的状态为Up。
以DeviceA的显示为例。
[~DeviceA] display bfd session all
(w): State in WTR (*): State is invalid ------------------------------------------------------------------------ Local Remote PeerIpAddr State Type Interface Name ------------------------------------------------------------------------ 1 2 10.1.1.2 Up S_IP_IF GigabitEthernet0/1/0 ------------------------------------------------------------------------ Total UP/DOWN Session Number : 1/0
- 使能IS-IS的快速感知功能
# 配置DeviceA。
[~DeviceA] interface gigabitethernet 0/1/0
[~DeviceA-GigabitEthernet0/1/0] isis bfd static
[*DeviceA-GigabitEthernet0/1/0] commit
[~DeviceA-GigabitEthernet0/1/0] quit
[~DeviceA] quit
# 配置DeviceB。
[~DeviceB] interface gigabitethernet 0/1/0
[~DeviceB-GigabitEthernet0/1/0] isis bfd static
[*DeviceB-GigabitEthernet0/1/0] commit
- 检查配置结果
# 在DeviceA上打开调试信息开关。
<DeviceA> debugging isis adjacency
<DeviceA> debugging isis circuit-information
<DeviceA> terminal debugging
# 对DeviceB的GigabitEthernet0/1/0接口执行shutdown命令,模拟链路故障。
[~DeviceB-GigabitEthernet0/1/0] shutdown
[*DeviceB-GigabitEthernet0/1/0] commit
# 在DeviceA上可以看到以下日志信息,表明IS-IS根据BFD报告的故障删除了与DeviceB的邻居关系。
#80/active/IsisAdjacencyChange/Major/occurredTime:2011-03-09 04:17:07/-/-/alarmI D:0x08960007/VS=0:ISIS adjacency state change. (SysInstance=1, SysLevel=1, CircI ndex=2, CircIfIndex=20, LspId=2222.2222.2222.00.00, AdjState=1, IfIndex=20, IfNa me=GE0/1/0, Reason=BFD detected that the neighbor went Down, SubReason=14)
配置文件
DeviceA的配置文件
#
sysname DeviceA
#
bfd
#
isis 1
is-level level-2
network-entity aa.1111.1111.1111.00
#
interface GigabitEthernet0/1/0
undo shutdown
ip address 10.1.1.1 255.255.255.0
isis enable 1
isis bfd static
#
bfd atob bind peer-ip 10.1.1.2 interface GigabitEthernet0/1/0
discriminator local 1
discriminator remote 2
#
return
DeviceB的配置文件
#
sysname DeviceB
#
bfd
#
isis 1
is-level level-2
network-entity aa.2222.2222.2222.00
#
interface GigabitEthernet0/1/0
undo shutdown
ip address 10.1.1.2 255.255.255.0
isis enable 1
isis bfd static
#
interface GigabitEthernet0/2/0
undo shutdown
ip address 10.2.1.1 255.255.255.0
isis enable 1
#
bfd btoa bind peer-ip 10.1.1.1 interface GigabitEthernet0/1/0
discriminator local 2
discriminator remote 1
#
return
DeviceC的配置文件
#
sysname DeviceC
#
isis 1
is-level level-2
network-entity aa.3333.3333.3333.00
#
interface GigabitEthernet0/1/0
undo shutdown
ip address 10.2.1.2 255.255.255.0
isis enable 1
#
return