WDS-AP to WDS-Sta (Atheros) Example

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Contents

Simple LAN WDS configuration

Objective

Connect 3 LAN using 2 GW2347 and 1 GW2348 and they will be transparent for the diferent Ethernet subnets.

  GW2347_0 - - - - - GW2348 - - - - - - GW2347_1
     |                 |                   |
    LAN               LAN                 LAN

Will support Spaning tree protocol to alow the case when GW2347's were in the same Ethernet segment. This case:

  GW2347_0 - - - - - GW2348
     |                 |
  GW2347_1 - - - - - - -

Definitions

The 3 LAN's are in the same IP subnet 10.1.1.0/24 (for example).

The GW234x management IP will be in 192.168.5.0/24 (for example).

All the GW234x has Winstron CM9 miniPCI cards into them.


Names of GW234x devices will be:

acbr51 with 192.168.2.51 for the GW2347_0

acbr52 with 192.168.2.52 for the GW2348

acbr53 with 192.168.2.53 for the GW2347_1

Prerequisites

All GW234x devices are with factory defaults configuration (all has their nvram erased using RedBoot commands).

All GW234x devices has DDWRT V24 pre - RC 7 (20080317) (or newer) flashed.

Configuring the devices

I only coment the parameters I changed or if the parameter value is important for our purpose.

IP Parameters

Setup->Basic Setup page

Section WAN:

  • Connection Type: Disabled
  • STP: Enabled

Section Optional Settings:

  • Router and Hostnames: acbr51, acbr52, acbr53 (each name with each device).
  • Domain Name: mydomain (put yours here if you want).

Section Router IP:

  • Local IP Address: 192.168.2.51, 192.168.2.52, 192.168.2.53 (each IP with each device)
  • Subnet Mask: 255.255.255.0
  • Gateway: 192.168.2.254 (leave in blank if you don't use)
  • Local DNS: 192.168.2.254 (leave in blank if you don't use)

Section DHCP:

  • DHCP Server: Disable (Enable and configure if you want, I don't use it here).

Section Time Settings:

  • Time Server: 192.168.2.254 (leave in blank if you don't use)

WiFi Parameters

Wireless -> Basic Settings page

In each interface I thanged this parameters:

  • Regulatory Domain: SPAIN (I'm in Spain).
  • Wireless Mode: AP (Will be a simple WDS).
  • Wireless Network Mode: A-Only (There are many home networks in 2,4GHz).
  • Turbo Mode: Enabled (Is not required, but I like it).
  • Outdoor Band: Enabled or Disabled. This allow you to select the indoor channels or the outdoor ones.
  • Wireless Network Name (SSID): myssid (I use the same in all interfaces).
  • Wireless Channel: 50-Indoor-Turbo for acbr51-acbr52 link and 130-Outdoor-Turbo for acbr52-acbr53 link.

The configuration will be:

                  CH50                           CH130
  acbr51 (ath0) - - - - - (ath0) acbr52 (ath1) - - - - - - (ath0) acbr53

NOTES:

  • With AP mode works fine the WDS disabling Turbo Mode'. You must wait a bit to see the comunication, but it works fine.
  • With AP mode works fine the WDS enabling Turbo Mode'. You must wait a bit to see the comunication, but it works fine.

Wireless -> Wireless Security page

I allways use WPA-PSK with AES with a large phrase. I'll don't change it now for a simple link.

For each interface in each device I use:

  • Security Mode: WPA-Personal
  • WPA Algorithms: AES
  • WPA Shared Key: AvErYlOnGpHrAsE (use a long key here).

Please, be sense in I use me own configuration, you can use this configuration too, but this is only an example of working configuration.

Notes for Outdoor links

  • Configure correctly the Antenna gain (minus the cable and connectors losses).
  • Configure correctly the distance (ack), is a tick for better performance with atheros chipsets (at least).
  • If you really don't need it, don't use diversity, use only (at least for WDS links) one antenna for TX and RX.
  • It's more safe to use long preamble that short preamble.
  • To guide your antenna don't use TurboMode, configure your device in a channel before use your laptop to put the antenna in the correct position. I use kismet for this purposes, and with TurboMode, I can see the signal correctly. Perhaps is my problem, but you are advised.
  • I repeat: Before use TurboMode, configure correctly your antennas in the correct position in all the sides of the links using normal channels/modes. Only use TurboMode when you have finished the phisical configuration of the links.

WDS Parameters

Wireless -> WDS page

For acbr51 (1 atheros only):

  • First column: LAN
  • Second column: the ethernet mac of acbr52 ath0 interface.
  • Third column: acbr52

For acbr52 (2 atheros):

  • First column: LAN in first row and LAN into second row.
  • Second column: the ethernet mac of acbr51 ath0 interface in the first row and acbr53 ath0 MAC into second row.
  • Third column: acbr51 into first row and acbr53 into the second row.

For acbr53 (1 atheros only):

  • First column: LAN
  • Second column: the ethernet mac of acbr52 ath1 interface.
  • Third column: acbr52

You must remenber this:

                  CH50                           CH130
  acbr51 (ath0) - - - - - (ath0) acbr52 (ath1) - - - - - - (ath0) acbr53