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I have a TP-Link Archer C2600 dual-band router set up in the first floor of my house that provides poor signal strength at the opposite 2nd story corner of my house.

In order to extend my wireless range and also connect upstairs devices in a wired configuration I bought a TP-Link Archer C5 dual-band router and successfully setup a WDS backhaul over the 2.4GHz band as instructed by this TP-Link article. See figure below

What I found interesting is that TP-Link instructs to configure WDS only on the extended/repeater router (C5 in my scenario) and to leave the root router (C2600) as-is. TP-Link calls this Active WDS for the Repeater and Passive WDS for the root router.

However, this article from Netgear requires configuration changes on both the root & repeater router such that both routers know each other's MAC address. Using TP-Link's terminology, this would be dual Active WDS

Is the difference between TP-Link's Passive/Active setup and Netgear's Active/Active setup merely a difference in configuration with the same end result, or is one setup superior than the other and if so, how?

My WDS Topology

  • Asking multiple questions in one Question-post doesn't fit the SuperUser/StackExchange format very well. It would probably be better to ask one question at a time. – Spiff Sep 30 '16 at 17:36
  • @Spiff ok, done. Hopefully you don't mind a few follow up questions in the comments. – SiegeX Oct 1 '16 at 4:44
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    WDS as used today is almost always proprietary. The activation could be triggered automatically. – Daniel B Oct 5 '16 at 21:39
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When configured for active WDS, all transmissions made to the other endpoint are done in 4-address mode. A side configured for active WDS can make the first transmission or it can wait for the other side to contact it first.

When passive WDS mode is used, the device cannot make the initial contact. But when the other side contacts it, if the other side uses 4-address mode, the side set to passive does too.

Obviously, active WDS must be used on at least one side, and that side must make the initial contact. Active WDS must be set up for a specific link to a specific device on the other end. Passive WDS is just an on/off switch for the access point and doesn't require any specific configuration for each link.

To use passive WDS, you have to allow any device that can connect to the AP to use 4-address mode. In some cases, this might be a security issue. Most home wireless networks don't implement any security model beyond just encryption and accept that anyone who knows the key can hijack any and all traffic, so this isn't really an issue.

A properly configured and established WDS link will ultimately be exactly the same, 4-address mode used in both directions, regardless of how it's established.

Setting active on both sides is more secure. Leaving the "main" AP passive and just setting active on the additional APs is easier to configure and manage. But unless you're doing something unusual with your security, it's just a matter of preference.

  • Can you please go into specifics about the 3-address vs 4-address mode – SiegeX Oct 10 '16 at 6:28
  • 4-address mode is what allows a wireless link to act like a bridge. Without it, an access point will only send on the air traffic that is bound for one of its clients. – David Schwartz Oct 10 '16 at 6:57
  • I'm looking more for details at the frame level. Can you show me what a 3-address frame looks like vs a 4-address frame and refer back to this detail to pinpoint why the 4-address frame enables bridging whereas the other does not. This is my requirement for full points. Thanks – SiegeX Oct 10 '16 at 18:14
  • I don't see how I can fit that into the scope of the answer. But the basic idea is that the 4-address frame includes the physical addresses of both endpoints of the wireless link as well as the physical addresses of both the originator and recipient of the frame. So when an AP wants to bridge an Ethernet packet it received, it can include both the hardware addresses of itself and the destination access point (so the Wifi part will work) and the original source and destination MACs of the Ethernet packet (so the bridging will work). – David Schwartz Oct 10 '16 at 18:25
  • Thank you for the explanation. So in the 3-address mode the router is basically doing a form of layer2 NAT in which the source MAC address is always the AP no matter the requesting client? – SiegeX Oct 11 '16 at 18:05
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They are different things; while the TP-Link article describe "Wireless Bridging" WDS mode the Netgear article describes the "Wireless Repeater" WDS mode.

from Wikipedia

Wireless bridging, in which WDS APs (AP-to-AP on sitecom routers AP)
 communicate only with each other and don't allow wireless stations 
 (STA) (also known as wireless clients) to access them

Wireless repeating, in which APs (WDS on sitecom routers) communicate 
 with each other and with wireless STAs
  • On the air it's really the same though. It's all about the magic 4-address mode. The TP-LINK guide also sets up repeating, in addition to bridging. – Daniel B Oct 5 '16 at 21:46
  • >On the air it's really the same though No it is not. One mode allows the stations sharing the WDS link access while the other mode does not. – Pat Oct 5 '16 at 22:03
  • That's just the APs decission. You could even allow clients on some but disallow them on others. WDS is only ever used for communication between APs and is the same in both "modes". – Daniel B Oct 5 '16 at 22:06
  • There are 2 different modes and the fact of sharing the stations access with the WDS link or not heavily affects WDS performance. – Pat Oct 5 '16 at 22:10

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