Fault Description

Network topology: PC -> ONU -> OLT (MA5600T) -> DHCP server -> Aggregation switch
Fault description: The OLT configured with firewall is connected to multiple ONUs. After enabling the DHCP server and being configured with NAT, the OLT is connected to the MAN aggregation switch. The PC cascaded to the ONU cannot obtain the IP address; however, if the PC is configured with a static IP address in the DHCP IP address pool, the PC can ping the gateway and access the Internet.

Alarm Information

None

Cause

Each user port of the ONU is allocated with a VLAN to achieve port isolation. In addition, ONU VLAN is switched on the OLT to save VLAN resources. In this case, the OLT has excessive broadcast domains. As a result, DHCP offer packets are lost.

Procedure

• Enable the debugging dhcp server packet on the firewall and capture packets. It is found that the firewall has transmitted DHCP offer packets but the PC does not receive these packets.
• Capture packets on the upstream port of the OLT. It is found that DHCP offer packets reach the OLT but are not transmitted to the PC.
• Configure the data again. That is, configure a smart VLAN on each ONU to reduce broadcast domains of the OLT. Then, test again. It is found that all the PCs can obtain IP addresses.
  

Suggestion and Summary

Ports in a smart VLAN are isolated. Therefore, isolation of user ports of an ONU can be achieved by configuring a smart VLAN on the ONU.

nice document.

Glad its useful to you.

good

Got the example, cases should be of fixed network only or MsoftX, SG700, HSS cases can also be posted.

This guide would be more useful if it snapshots are used for the ease of understanding.

Buenas! amigos (@) disculpen! Sera que me pueden ayudar con un Viewpoint 8210 que no encuentro forma de como usarlo no me reconoce el ip,
ni la pc.. y el manual no me ayuda mucho..!

Useful information

In this post, no have the of number of DHCP , and what is the problem if DHCP is out of range.

the network topology is not exact, because the OLT-> Siterouter-->DHCP server, OLT not connected direct to DHCP server