第三方传输设备不能透传NE40E发出的带vlan标记的BFD检测报文导致BFD震荡

发布时间:  2012-12-17 浏览次数:  77 下载次数:  0
问题描述

M国某运营商采用NE40E配置BFD,中间有传输设备
组网
NE40E(PE设备)-----传输-----NE40E(PE设备)

NE40E通过vlanif接口绑定单播BFD,对接以后发现大量BFD闪断日志,间隔非常短,链路无法工作。
Apr 28 2012 00:35:49  %%01BFD/4/STACHG_TODWN(l)[0]:Slot=1;BFD session changed to Down. (SlotNumber=1, Discriminator=15680, Diagnostic=DetectDown, Applications=ISISL1, ProcessPST=False, BindInterfaceName=Vlanif2, InterfacePhysicalState=Down, InterfaceProtocolState=Down)
Apr 28 2012 00:35:49  %%01BFD/4/STACHG_TOUP(l)[1]:Slot=1;BFD session changed to Up. (SlotNumber=1, Discriminator=15680, FormerStatus=Init, Applications=ISISL1, BindInterfaceName=Vlanif2, ProcessPST=False)
Apr 28 2012 00:35:49  %%01BFD/4/STACHG_TODWN(l)[2]:Slot=1;BFD session changed to Down. (SlotNumber=1, Discriminator=15680, Diagnostic=DetectDown, Applications=ISISL1, ProcessPST=False, BindInterfaceName=Vlanif2, InterfacePhysicalState=Down, InterfaceProtocolState=Down)
Apr 28 2012 00:35:49  %%01BFD/4/STACHG_TOUP(l)[3]:Slot=1;BFD session changed to Up. (SlotNumber=1, Discriminator=15680, FormerStatus=Init, Applications=ISISL1, BindInterfaceName=Vlanif2, ProcessPST=False)
Apr 28 2012 00:35:46  %%01BFD/4/STACHG_TODWN(l)[4]:Slot=1;BFD session changed to Down. (SlotNumber=1, Discriminator=15679, Diagnostic=DetectDown, Applications=ISISL1, ProcessPST=False, BindInterfaceName=Vlanif2, InterfacePhysicalState=Down, InterfaceProtocolState=Down)
Apr 28 2012 00:35:46  %%01BFD/4/STACHG_TOUP(l)[5]:Slot=1;BFD session changed to Up. (SlotNumber=1, Discriminator=15679, FormerStatus=Down, Applications=ISISL1, BindInterfaceName=Vlanif2, ProcessPST=False)

处理过程

1. 修改传输设备配置允许带vlan的报文通过

2. 使用组播BFD代替单播BFD,并联动端口配置如下

[RouterA] bfd atob bind peer-ip default-ip interface GE x/x/x

                    ---表示单跳组播bfd

[RouterA-bfd-session-atob] discriminator local 10

[RouterA-bfd-session-atob] discriminator remote 20

[RouterA-bfd-session-atob] min-tx-interval 10

[RouterA-bfd-session-atob] min-rx-interval 10

[RouterA-bfd-session-atob]process-interface-status

                    ---联动端口

[RouterA-bfd-session-atob] commit

[RouterA-bfd-session-atob] quit
根因
NE40E使用vlanif+BFD场景,发出的BFD检测报文带vlan,BFD协商报文不带vlan。中间的传输设备不支持透传带vlan的报文导致BFD反复协商中断。
解决方案

1. 修改传输设备配置允许带vlan的报文通过

2. 使用组播BFD代替单播BFD,并联动端口配置如下

[RouterA] bfd atob bind peer-ip default-ip interface GE x/x/x

                    ---表示单跳组播bfd

[RouterA-bfd-session-atob] discriminator local 10

[RouterA-bfd-session-atob] discriminator remote 20

[RouterA-bfd-session-atob] min-tx-interval 10

[RouterA-bfd-session-atob] min-rx-interval 10

[RouterA-bfd-session-atob]process-interface-status

                    ---联动端口

[RouterA-bfd-session-atob] commit

[RouterA-bfd-session-atob] quit

END