VLAN TAGGING Issue on ATN950B / ATN910I

Created: Oct 7, 2021 16:32:15Latest reply: Nov 29, 2021 05:22:11 368 16 9 0 0

Keywords :

VLAN TAGGING, ATN950B/910I, Port default Vlan, V2R2

Abstract :

ATN950B / ATN 910I running the Version 5.120 (ATN950B V200R002C00SPC300) cannot process untagged traffic. This was observed when migrating RedMax (Wimax 16D ) equipment from Cisco 2960 switch to Huawei ATN950B / ATN910 I Router

Fault Type :

Interconnection>>To Access Network Device

Issue Description :

Fault Symptom :

After traffic migration from Cisco 2960 switch to Huawei ATN, customers connected behind the RedMax equipment connected to the Huawei ATN could no more establish a PPPoE session with BRAS. They could therefore not go to the internet

Version Information :

Huawei Versatile Routing Platform Software

VRP (R) software, Version 5.120 (ATN950B V200R002C00SPC300)

Networking Overview:

Clients have an outdoor equipment that have a Line of Sight with the Operator Base station (RedMax Equipment) that permit them to use Wimax16D service (Fixed Wimax). These customers go to the internet when they establish a PPPoE session with the BRAS (BNG). Customer sends untagged traffic, which must be tagged at the entry of the network equipment and transported right up to the BRAS permiting them to go to the internet.

Customer uses a PPPoE client and inputs a username and a password to go to the internet.

Network Topology :

b80fae31146a4d95ad8c4590ec123f18

Configuration Script (Interface of router facing Redmax).

N.B VPLS configured on the metro network to carry customer VLAN right up to the BRAS (BNG)

interface GigabitEthernet0/4/0

portswitch

description To_RedMAX_AN-100U-UX

undo shutdown

port link-type access

port default vlan 427

dcn

%%%%%%%%%%% Uplink of Router %%%%%%%%%%

interface GigabitEthernet0/4/1

portswitch

description Router_Uplink

undo shutdown

port link-type trunk

port trunk allow-pass vlan 427

dcn

Troubleshooting Process :

1. Before migration, a Laptop is connected to the Cisco switch. Using the right username and password on the PPPoE client, the user could establish a PPPoE session with the BRAS and go to the internet.

2. Downlink and uplink are disconnected from switch and connected to router but the client cannot go to the internet.

3. Display the MAC address table of the router and discover no MAC address is learnt on the VLAN 427 on the port Gi0/4/1

MAC address table of slot 0:

-------------------------------------------------------------------------------

MAC Address VLAN/ PEVLAN CEVLAN Port Type LSP/LSR-ID

VSI/SI MAC-Tunnel

-------------------------------------------------------------------------------

d0d0-4bd2-da02 462 - - GE0/3/1 dynamic 0/-

d0d0-4bd2-da02 562 - - GE0/3/1 dynamic 0/-

d0d0-4bd2-da02 1802 - - GE0/3/1 dynamic 0/-

d0d0-4bd2-da02 662 - - GE0/3/1 dynamic 0/-

-------------------------------------------------------------------------------

Total matching items on slot 0 displayed = 4

Root Cause :

ATN cannot process untagged traffic even when using the "port default vlan" command on the access port.

Solution :

3 Solutions were done :

Solution 1:

The cisco switch was used between the RedMax Equipment and the router. The Cisco switch could then tag the untagged traffic using the "native VLAN" command and the router configured with TRUNK PORTS for both downlink and uplink. Client could go to the internet successfully. This solution is not optimal because our objective was to swap the Cisco switch.

Solution 2 :

Using the external Loop on the ATN. This is shown below with related configs (VPLS deployed between routers : VSI Name is TEST)

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