某局点 S7503X 终端拿不到地址（epon组网）的经验案例

组网说明：

终端MAC: B06E-BFAA-E614

OLT端口 ：2/3/0/12

ONU接口：2/3/0/12:7

UNI接口  ： 1

epon组网下，终端拿不到地址，但是手动指定能ping通网关地址。另外拔掉该槽位其余olt接口带业务端口的光纤，只保留测试onu端口在位，终端可正常获取地址，但在其余业务同时在位时，无法获取动态IP。

1、onu在位情况：

---------------------------------- Olt2/3/0/12 ---------------------------------

 MAC LOID LLID Dist(M) Port Model/Version Sft/Epm State Aging

 305f-779f-8090 6 <1000 Onu2/3/0/12:7 ET908-H-POE/A 113/ Up N/A 

2、对应onu下uni接口的配置情况：

 interface Onu2/3/0/12:7

  bind onu-id 305f-779f-8090

  uni 1 vlan-mode tag pvid 5

  uni 2 vlan-mode tag pvid 5

  port link-type trunk

  undo port trunk permit vlan 1

  port trunk permit vlan 2 to 14 200

 interface Olt2/3/0/12

 using onu 1 to 24

 port link-type trunk

 undo port trunk permit vlan 1

 port trunk permit vlan 2 to 14 100 to 112 200

3、dhcp的配置情况，查看free-ip也是足够的

 dhcp server ip-pool vlan5

  gateway-list 10.4.5.1

  network 10.4.5.0 mask 255.255.255.0

  dns-list 219.134.188.113 114.114.114.114

4、debug dhcp server，dhcp的交互报文已经拿到了地址。

 *Sep 24 10:57:07:620 2021 core-S7500X DHCPS/7/PACKET: -MDC=1; From 0.0.0.0 port 68, interface Vlan-interface5

     Message type: REQUEST (1)

     Hardware type: 1, Hardware address length: 6

     Hops: 0, Transaction ID: 2431258094

     Seconds: 6400, Broadcast flag: 0

     Client IP address: 0.0.0.0   Your IP address: 0.0.0.0

     Server IP address: 0.0.0.0   Relay agent IP address: 0.0.0.0

     Client hardware address: b06e-bfaa-e614

     Server host name: not configured

     Boot file name: not configured

     DHCP message type: DHCPREQUEST (3)

 *Sep 24 10:57:07:620 2021 core-S7500X DHCPS/7/EVENT: -MDC=1; Receive a DHCPREQUEST message for 10.4.5.3 from Vlan-interface5; The server identifier is 10.4.5.1.

 *Sep 24 10:57:07:620 2021 core-S7500X DHCPS/7/EVENT: -MDC=1; The client selected the local server.

 *Sep 24 10:57:07:621 2021 core-S7500X DHCPS/7/EVENT: -MDC=1; Send a DHCPACK message on Vlan-interface5.

 *Sep 24 10:57:07:621 2021 core-S7500X DHCPS/7/PACKET: -MDC=1; To 10.4.5.3 port 68, interface Vlan-interface5

     Message type: REPLY (2)

     Hardware type: 1, Hardware address length: 6

     Hops: 0, Transaction ID: 2431258094

     Seconds: 6400, Broadcast flag: 0

     Client IP address: 0.0.0.0   Your IP address: 10.4.5.3

     Server IP address: 0.0.0.0   Relay agent IP address: 0.0.0.0

     Client hardware address: b06e-bfaa-e614

     Server host name: not configured

     Boot file name: not configured

     DHCP message type: DHCPACK (5)

 地址池已经有地址了；

 [core-S7500X]display dhcp server ip-in-use pool vlan5

 IP address Client-identifier/ Lease expiration Type Hardware address

 10.4.5.3 01b0-6ebf-aae6-14 Sep 25 15:12:53 2021 Auto(C)  

5、现场测试刷新一下终端网卡再获取的时候，没有相关dhcp报文上送，终端拿不到地址；查看对应onu接口，发现广播包上送过多

 - Onu2/3/0/12:7(UP)  输入广播多,广播报文(154350)占总报文数(161882) 95%

 EPON网络中终端设备很多，容易形成几千台终端的二层域问题。这种情况下会有较多的广播报文，尤其ARP报文过多时可能影响业务。此时可以配置OLT端口、ONU接口的二层端口隔离功能，降低广播报文影响。

后续现场加端口隔离组测试没有问题

 interface Olt2/3/0/10

 port-isolate enable group 1

 using onu 1 to 24

 port link-type trunk

 undo port trunk permit vlan 1

 port trunk permit vlan 2 to 14 100 to 112 200

 #            

 interface Olt2/3/0/11

 port-isolate enable group 1

 using onu 1 to 24

 port link-type trunk

 undo port trunk permit vlan 1

 port trunk permit vlan 2 to 14 100 to 110 200

 #

 interface Olt2/3/0/12

 port-isolate enable group 1

 using onu 1 to 24

 port link-type trunk

 undo port trunk permit vlan 1

 port trunk permit vlan 2 to 14 100 to 112 200