Configure VLAN on Industrial Wireless Access Points in CURWB Mode

Introduction

This document describes the VLAN configuration on Industrial Wireless (IW) Access Points so they can pass tagged traffic over Wireless. 

Background Information

Cisco Ultra-Reliable Wireless Backhaul (CURWB) lets you connect remote buildings both fixed or moving assets to your network.

It provides a high data rate, ultra-low latency and packet loss, and seamless handoffs.

Prerequisites

If you want to send VLAN traffic over wireless, the VLAN feature needs to be activated on all the Access Points in the cluster.

The VLAN feature is used to receive and transmit packets with VLAN tags on the radios.

This is not a default feature and requires the designated radios to have an FM-VLAN license installed and activated.

Once the VLAN feature is enabled, the user can edit two different settings on the radio:

• Management VLAN
• Native VLAN

VLAN Settings

• Management VLAN: The Management VLAN ID is the VLAN identity tag at which the radio can be accessed to make control plane changes. The management VLAN facilitates administrative access to the radio through the GUI & CLI. The default value of Management VLAN ID is ‘1’, and can be changed.
• Native VLAN: Incoming untagged packets are tagged with this VLAN number.
  • Default: 1
  • If configured as “0”, the incoming untagged packets are dropped.
  • If the radio is configured to be in “mesh end” mode, the incoming packets tagged with the configured native VLAN tag are forwarded untagged.

Configuration Steps

1. Activate VLAN feature on the IW radios. Note: With IW licensing model all features (except bandwidth) are available out of the box.
2. Navigate to VLAN tab of the GUI to configure the Management VLAN and Native VLAN.
3. Set the Management VLAN ID.
4. Set the Native VLAN ID. The radio uses it to tag untagged packet. If it is set to 0, the radio just drops all untagged packets.

The  VLAN configuration is the same on all radios in the cluster and, by default, Management and Native VLANs are set to 1. You can also configure smart VLAN from the CLI and the process is as follows:

CLI configuration

#configure vlan management X (where X is an integer from 1 to 1024 and represents the Management Vlan ID)
#configure vlan native Y (where Y is an integer from 1 to 1024 and represents the Native Vlan ID)
#write (to save the configuration)
#reload (to reboot the radio and apply the changes)

Note: Both management and native VLANs can be configured to be the same.

Native & Management VLAN Scenarios

This image depicts three scenarios where the radios forward VLAN tags and how the native VLAN works.

Scenario 1: If the native VLAN on the radio is set to 0, any untagged traffic is dropped by the radio as the radio receives the packet.

Scenario 2: If the native VLAN on both the CURWB radios is set to VLAN 75 and the incoming traffic has  VLAN 100 and untagged traffic, the untagged traffic goes over the CURWB radio after it gets tagged by CURWB radio's own native VLAN. However, after leaving the CURWB radios and entering the corporate network, VLAN tags of all VLAN 75 traffic is stripped off. After which, there is only the tagged VLAN 100 and untagged traffic.

Scenario 3: If the native VLAN of CURWB radio needs to be tagged permanently so even after it leaves the radio and enters the corporate network with VLAN 200, then remote CURWB radio needs to have a VLAN other than VLAN 200. In this example, the Mesh End has a Native VLAN of 75, and the Mesh Point with a native VLAN of 200. For Untagged traffic originating from the mesh point side, it is tagged as VLAN 200, arriving at the Mesh End the native VLANs do not match causing it to be tagged permanently as VLAN 200 into the corporate network.  

CURWB Management VLAN & MPLS encapsulation

This image is a common Point to Multipoint architecture.  On the left, we have a Mesh-End radio connected to a VLAN-tagged Layer 2 network.  CURWB preserves Layer 2 within our Prodigy protocol (shown as note 3) and adds the additional MPLS headers and VLAN tags to the datagram, then sends the data over the air to the Mesh-Point radios on the right.  At the receiving Mesh Point side, the MPLS and Management headers are stripped, and the data is presented as the usual tagged Ethernet traffic on the other side.

VLAN configuration in a lab setup

Here is a sample lab configuration for reference.

SWITCH 1 CONFIG

Switch1#show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID                     Local Intrfce    Holdtme          Capability        Platform          Port ID

MP_TRK_Backhaul      Gig 0/23          121                  R T                   IW9165DH-     Gig 0

Switch1#show ip interface brief

Interface                     IP-Address                   OK?                 Method           Status                                      Protocol

Vlan1                           unassigned                  YES                  NVRAM           administratively down            down   

Vlan500                       192.168.6.100             YES                  manual            up                                            up     

Vlan581                       10.122.136.1               YES                  NVRAM           up                                            up     

GigabitEthernet0/23   unassigned                  YES                  unset               up                                            up     

Switch1#show interfaces trunk

Port                 Mode              Encapsulation Status              Native vlan

Gi0/23             on                    802.1q             trunking          1

Port                 Vlans allowed on trunk

Gi0/23             500,581

Port                 Vlans allowed and active in management domain

Gi0/23             500,581

Port                 Vlans in spanning tree forwarding state and not pruned

Gi0/23             500,581

Switch1#show running-config interface g0/23

Building configuration...

Current configuration : 137 bytes

!

interface GigabitEthernet0/23

 switchport trunk encapsulation dot1q

 switchport trunk allowed vlan 500,581

 switchport mode trunk

end

RADIO 1 CONFIG:

Radio1#show ip

IP: 10.122.136.9

Network: 255.255.255.192

Gateway: 10.122.136.1

Nameservers: 64.102.6.247

Radio1#show vlan

VLAN status: enabled

Management VID: 581

Native VID: 0

RADIO 2 CONFIG:

Radio2#show ip

IP: 10.122.136.15

Network: 255.255.255.192

Gateway: 10.122.136.1

Nameservers: 64.102.6.247

Radio2#show vlan

VLAN status: enabled

Management VID: 581

Native VID: 0

SWITCH 2 CONFIG

Switch2#show cdp neighbors

Capability Codes:        R - Router,       T - Trans Bridge,          B - Source Route Bridge

S - Switch,       H - Host,                      I - IGMP,          r - Repeater,    P - Phone,

D - Remote,     C - CVTA,                     M - Two-port Mac Relay

Device ID         Local Intrfce    Holdtme          Capability        Platform          Port ID

Radio2             Gig 1/0/3         135                  R T                   IW9165DH-     Gig 0

Switch2#show ip interface brief

Interface                     IP-Address       OK?     Method           Status                                      Protocol

Vlan1                           unassigned      YES      NVRAM           administratively down            down   

Vlan500                       192.168.6.101 YES      NVRAM           up                                            up     

Vlan581                       10.122.136.35 YES      NVRAM           up                                            up     

GigabitEthernet1/0/3   unassigned    YES      unset               up                                            up 

Switch2#show interface trunk

Port                 Mode              Encapsulation             Status              Native vlan 

Gi1/0/3           on                    802.1q                         trunking          1

Port                 Vlans allowed on trunk

Gi1/0/3           500,581

Port                 Vlans allowed and active in management domain

Gi1/0/3           500,581

Port                 Vlans in spanning tree forwarding state and not pruned

Gi1/0/3           500,581

Switch2#show running-config interface Gi1/0/3

Building configuration...

Current configuration : 100 bytes

!

interface GigabitEthernet1/0/3

 switchport trunk allowed vlan 500,581

 switchport mode trunk

end

With this configuration, VLAN 500 can communicate over wireless. Now it is important to note that while configuring VLAN on a Layer 2 network, Layer 3/multiple subnet fluidity cannot be configured.