The NE40E IPoE Terminal Is Slow in Obtaining IP Addresses

1.Log in to the NE40E to check the cause of the user online failure. It is found that the DCHP server times out in waiting for packets sent from DHCP clients.
2. Enable full message tracing on the terminal to analyze the tracing information.
Mar 13 2018 16:48:21.900.2 BTRC/7/BTRC_TraceInfo:[objectID=1][slotID=1][DHCPA][user info:
MAC Address : XXXX-XXXX-F00E
Interface : Eth-TrunkXX.XX41
PE VLAN ID : 2024
CE VLAN ID : 1171
Access Mode : IPoE ]
[trace info:
DHCPA receive a packet.
DHCPA receive a DISCOVER pkt —Discovery packets are received.
—-
Mar 13 2018 16:48:21.900.14 BTRC/7/BTRC_TraceInfo:[objectID=1][slotID=0][AAA][user info:
MAC Address : XXXX-XXXX-F00E
IP Address : 255.255.255.255
Interface : Eth-TrunkXX.XX41
PE VLAN ID : 2024
CE VLAN ID : 1171
User Name : X-NE40E–01231202401171@X]
[trace info: User authentication success] —The authentication succeeds.
—-
Mar 13 2018 16:48:21.900.30 BTRC/7/BTRC_TraceInfo:[objectID=1][slotID=0][AM][user info:
MAC Address : XXXX-XXXX-F00E
IP Address : 255.255.255.255
Interface : Eth-TrunkXX.XX41
PE VLAN ID : 2024
CE VLAN ID : 1171
User Name : X-NE40E–01231202401171@X]
[trace info:
[AM]Allocate IP address for DHCPS successfully.] —The IP address is successfully allocated.
—-
Mar 13 2018 16:48:21.900.40 BTRC/7/BTRC_TraceInfo:[objectID=1][slotID=0][DHCPACC][user info:
MAC Address : XXXX-XXXX-F00E
IP Address : 10.46.4.47
Interface : Eth-TrunkXX.XX41
PE VLAN ID : 2024
CE VLAN ID : 1171
Access Mode : IPoE
Circuit ID : 0021F-1171-TRUNK
Remote ID : huawei-0021F-1171-TRUNK ]
[trace info:
DHCPACC send a packet to client. —An Offer message is sent to the client.
DHCPACC proc a OFFER pkt
Giaddr:0A2E0001 Yiaddr:0A2E042F
DhcpaccIndex:244131, DhcpaIndex:65535, cib:254486, state:3(DHCPACC_DIS_WAIT_SERVER_OFFER), DownReason:255]
Mar 13 2018 16:48:24.890.2 BTRC/7/BTRC_TraceInfo:[objectID=1][slotID=1][DHCPA][user info:
MAC Address : XXXX-XXXX-F00E
Interface : Eth-TrunkXX.XX41
PE VLAN ID : 2024
CE VLAN ID : 1171
Access Mode : IPoE ]
[trace info:
DHCPA receive a packet.
DHCPA receive a DISCOVER pkt—-DHCP Request messages are not received from the client after 3s, and the user online fails. The client re-initiates the sending of DHCP Discovery messages, but the problem persists.
3. Mirror packets on the upstream and downstream interfaces on the S77. Connect the PC for packet header obtaining. Analyze the packet header obtaining information.


—DHCP Offer messages are obtained, and the MAC address of the client is correct. The dhcp-broadcast configuration exists on the BAS interface. Therefore, the DHCP Offer messages are broadcast packets.
4. Check the OLT. It is found that all the upstream interfaces on the OLT are configured with the broadcast suppression level of 3.

—All the broadcast packets can be transmitted at a minimum rate of 24 kbps and a maximum rate of 48 pps. The upstream broadcast packets on the NE40 are discarded frequently.

The dhcp-broadcast configuration on the BAS interface allows the device to send DHCP unicast packets as broadcast packets.
In addition, all the uplink interfaces on the OLT are configured with a broadcast suppression level of 3, allowing packets to be transmitted at a minimum rate of 24kbps and a maximum rate of 48 pps. The downstream broadcast packets on the NE40 are discarded frequently.

1.Run the following command on the OLT to change the broadcast suppression level of interfaces:
MA5680T-1(config-if-giu-0/19)#
MA5680T-1(config-if-giu-0/19)#traffic-suppress
{ all<K>|portid<U><0,1> }:all
{ broadcast<K>|multicast<K>|unicast<K> }:broadcast
{ value<K> }:value
{ value<L><1,13> }:7

Command: traffic-suppress all broadcast  value  7

MA5680T-1(config-if-giu-0/19)#quit

MA5680T-1(config)#interface  giu  0/20
MA5680T-1(config-if-giu-0/20)#traffic-suppress all broadcast value 7
MA5680T-1(config-if-giu-0/20)#
MA5680T-1(config-if-giu-0/20)#
MA5680T-1(config-if-giu-0/20)#quit2. Delete the dhcp-broadcast configuration from the BAS interface.