1.1 基站DHCP上线失败的典型故障定位指导 故障现象 基站DHCP上线失败,DHCP服务器不能给基站分配地址。 常见原因 基站DHCP上线失败故障的常见原因主要包括: l 没有使能DHCP relay功能。 l DHCP服务器不可达。 l DHCP报文携带的源IP、VLAN错误。 故障诊断流程 可按照故障诊断流程图1-1排除此类故障。 图1-1 基站DHCP上线失败故障诊断流程图 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image002.png 故障处理步骤 背景信息 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg IPRAN设备在DHCP上线过程中的角色一般是中继角色。 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image006.png 请保存以下步骤的执行结果,以便在故障无法解决时快速收集和反馈信息。 操作步骤 步骤 1 在中继设备上查看DHCP报文收发状态。 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image007.jpg IPRAN设备在DHCP上线过程中的角色一般是中继角色。其工作过程如图1-2所示。 图1-2 DHCP中继工作过程 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image009.jpg 多次执行display dhcp relaystatistics命令查看DHCP relay设备上的DHCP报文计数。根据DHCP中继工作过程,对比中继设备上的DHCP报文个数,进行故障定界。 1) DHCP packets received from clients报文不增长,请执行 步骤2。 2) DHCP中继收到基站发送的DHCP探测报文,并且发送给DHCP server,但是没有收到DHCP server的回应报文,请执行 步骤3。 DHCP DISCOVER packets received = DHCP packets sent to servers DHCP packets received from servers = 0 3) 如果按照中继工作过程,DHCP中继从基站侧和DHCP server方向收发的报文个数一致,那么请联系基站侧工程师进行分析。 DHCP packets received from clients = DHCP packets sent to servers DHCP packets received from servers = DHCP packets sent to clients file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg 当历史记录信息影响问题判断的时候可以使用reset dhcp relay statistics命令用来清除DHCPv4中继的统计信息。 [HUAWEI]display dhcp relay statistics
Bad Packets recieved: 0
DHCP packets received from clients: 0
DHCP DISCOVER packets received: 0
DHCP REQUEST packets received: 0
DHCP INFORM packets received: 0
DHCP DECLINE packets received: 0
DHCP RELEASE packets received: 0
DHCP packets received from servers: 0
DHCP OFFER packets received: 0
DHCP ACK packets received: 0
DHCP NAK packets received: 0
DHCP packets sent to servers: 0
DHCP packets sent to clients: 0
Unicast packets sent to clients: 0
Broadcast packets sent to clients: 0 表1 display dhcp relay statistics命令输出信息描述 项目 | | | | DHCP packets received from clients | | DHCP DISCOVER packets received | | DHCP REQUEST packets received | | DHCP INFORM packets received | | DHCP DECLINE packets received | | DHCP packets received from servers | | DHCP OFFER packets received | | DHCP ACK packets received | | DHCP NAK packets received | | DHCP packets sent to servers | | DHCP packets sent to clients | | Unicast packets sent to clients | | Broadcast packets sent to clients | |
步骤 2 根据与基站相连的端口入向广播报文统计,判断是否基站侧故障。 多次执行display interfaceGigabitEthernet x/x/x命令查看对应主接口下广播报文统计是否增长。 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg 基站侧发送的DHCP探测报文为广播报文。 <HUAWEI> display interface GigabitEthernet 0/3/2 GigabitEthernet0/3/2 current state :UP … … Input: Unicast: 0 packets, Multicast: 0 packets Broadcast: 12packets, JumboOctets: 0 packets CRC: 0 packets, Symbol: 0 packets Overrun: 0 packets, InRangeLength: 0 packets LongPacket: 0 packets, Jabber: 0 packets, Alignment: 0 packets Fragment: 0 packets, Undersized Frame: 0 packets RxPause: 0 packets 如果没有增长,请联系基站侧定位;如果有增长,初步可以判断基站侧已经在发送探测报文,请执行步骤3。 步骤 3 检查DHCP中继配置是否完整。 执行display current-configuration interface GigabitEthernet x/x/x.xx命令确认端口下是否使能DHCP relay功能并指定了DHCP服务器地址。 <HUAWEI> displaycurrent-configuration interface GigabitEthernet 0/3/2.200 interface GigabitEthernet0/3/2.200 vlan-type dot1q 300 ip binding vpn-instance LTE-OAM-VPN ip address 10.109.2.184255.255.255.252 ip relay address 10.100.65.65 //指定DHCP 服务器地址 dhcp select relay //配置DHCP relay 功能 如果配置不全请补全配置,并观察问题是否解决;如果已经配置,请执行步骤4 。 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg 如果ip relay address配置在一个私网口,那么该服务器IP属于私网IP。一般情况下都配置在私网口下。 步骤 4 确认在开启DHCP Relay功能的接口下是否已经配置ip relaysource-ip-address 0.0.0.0。 如果场景满足以下条件,则需要增加source-ip-address配置: 1)L3VPN场景下,仅针对HVPN,L2+L3不存在此问题; 2)有两个以上厂家基站上线,且有不同的DHCP server; 3)某厂家无线网管侧对私网侧地址进行防火墙设置,丢弃非无线配置网段的报文。 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg relay接口配置ip relaysource-ip-address 0.0.0.0,relay转发client发送来的discover报文时,重新封装源IP为relay接口的IP。 <HUAWEI> display interfaceGigabitEthernet 0/3/2.200 vlan-type dot1q 300 ip binding vpn-instance LTE-OAM-VPN ip address 24.1.1.1 255.255.255.252 statistic enable ip relay address 10.100.65.65 dhcp select relay ip relay source-ip-address 0.0.0.0 //增加该命令 file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg 910&950的V200R001C02SPC200之前版本需要升级到V200R001C02SPC200并打上V200R001SPH009(包含)及之后的补丁会增加ip relay source-ip-address的命令行 910&910i的V200R002C00版本需要打上V200R002SPH005(包含)及之后的补丁会增加ip relaysource-ip-address的命令行 950B的V200R001C02之前版本需要升级到V200R001C02并打上V200R001SPH008(包含)及之后的补丁会增加ip relay source-ip-address的命令行 950B的V200R002C00版本需要打上V200R002SPH002(包含)及之后的补丁会增加ip relaysource-ip-address的命令行 增加该配置后在relay 设备上ping 基站的预分配地址,来触发基站侧学习VLAN 信息,然后观察问题是否解决,如果没有解决,请执行步骤5 。 步骤 5 检查DHCP服务器是否可达。 通过ping测试判断relay设备到DHCP服务器是否可达。 <HUAWEI>ping -vpn-instance LTE-OAM-VPN–a 24.1.1.1 10.100.65.65 PING 10.100.65.65: 56 data bytes,press CTRL_C to break Reply from 10.100.65.65: bytes=56 Sequence=1 ttl=255 time=3 ms … … Reply from 10.100.65.65: bytes=56 Sequence=5 ttl=255 time=1 ms --- 10.100.65.65 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-tripmin/avg/max = 1/1/3 ms file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg –a参数用来设置ping报文携带源IP为与基站相连端口IP。 如果可达请执行步骤6 ,如果不可达请排查IPRAN 网络内设备到DHCP 服务器IP 的路由是否正常,是否存在防火墙设置,如果路由正常,确认无防火墙设置,请执行步骤7 。 步骤 6 对与基站相连的端口的IP处于同一网段的地址进行ping操作,触发ARP请求报文,以便对端学习到正确的VLAN。 <HUAWEI>ping -vpn-instance LTE-OAM-VPN24.1.1.2 Ping包触发ARP请求后,请观察是否基站正常上线,如果故障依然存在,请执行 步骤7。 步骤 7 请收集如下信息,并联系华为技术工程师 l 上述步骤的执行结果。 l 设备的配置文件、日志信息、告警信息。 ----结束 相关告警与日志 相关告警 无 相关日志 无
|