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Mikrotik hAP ac2 new feature: Xlinks or Cross-linking

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Mikrotik hAP ac2 new feature: Xlinks or Cross-linking

Hello, through a conversation with forum members, I was told to look at this new feature that makes it possible to make a link between two aredn mesh zones ( A and B). "Cross-linking" allows one to create a big AREDN mesh by passing AREDN traffic across an existing non-AREDN P2P link.
In my case we have a preexisting P2P link made with non-AREDN radio. This is an extended network that carries the same subnet to a remote office as shown on the attached picture.
Question: how do we configure Mikrotik ac2 (Gateway) in zone 1 to talk to Mikrotik ac2 in zone 2 over that P2P link ?
In the attached  picture you will see that the first Mikrotik is getting a IP address from an external network DHC ( and the second Mikrotik in zone 2 is getting a WAN address  from the same DCHP as the first Mikrotik ac2 Gateway.
What can I put in the Xlinks field ?
What would be the IP address to put ?
What would be the peer address to put ?
Will I connect the ac2 WAN port to any LAN port of the existing non AREDN Network ?
Sorry but I would like to know how these two devices can discover each other over one big P2P link that is made a non AREDN network.

The new feature can be seen here:

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nc8q's picture
Will I connect the ac2 WAN port to any LAN port of the existing

"Will I connect the ac2 WAN port to any LAN port of the existing non AREDN Network ?"
I think no.
I think connect each ac2 DtD port to LAN port of existing non AREDN network.

73, Chuck


Thanks for your reply...

Thanks for your reply...
There is something magic happening with this feature and I can't explain it...
Here what I did.
Office 1 location configuration:
I took a cable and I pugged it in the DCHP router (Non aredn) on a LAN port.
and I took the same cable end and I plugged it in the ac2 DtD device but on port 5 that is described as dtdlink vlan: 2 (see online advanced network configuration).

Office 2 location configuration (remote):
I took a cable plugged it in a local switch. The other end of the cable, I plugged it in the ac2 DtD device on port 5 just like the other ac2 device that I configured in the main office. To my surprise, these two devices can see each other when I go to Mesh status of both ac2 devices. I really can't explain that magic but it works... The only problem is that internet is not available when I use both devices port 5...
How can I have internet from the main office when I use the dtdlink on port 5 ?
So far the xlinks field is still blank, I dont know what IP or PEER ADDRESS to put in.

nc8q's picture

If you are in a experimentation mood, what if you used 2 ethernet cables on each ac2.
Office1-ac2 WAN and DtD plugged into the home-router LAN,
Office2-ac2 WAN and DtD plugged into the Office2 switch (same LAN as the home-router)
The ac2's x-link IPs would be an unused pair (not in the pool) static 192.168.1.x addresses.

73, Chuck

Want an easier way?

Just use a tunnel between the hAPs. You do want to have at least one of them have a static address to be the tunnel server and the other can have a static or a dynamic address. Dirt simple to setup and pretty robust. Then you don't have to have any special setups or configuraitons for the link. As long as one node can hit the other over IP your tunnel should come up and the 2 mesh networks will be connected.

It would be great if the AREDN team would expand the documentation around Xlink. I will admit the current documentation is way better than what was there (nearly notihing) when I was looking at using Xlink for an application. But there are still some questions outstanding in my mind as to if Xlink could be used or not. That is why I tend to shy away from Xlink--just a few too many unknowns because there is not any technical information about what they are doing.

Hello, yes tunnel sounds like

Hello, yes tunnel sounds like an easy way. I just tried it. It worked. Can anybody put side to side the pros and cons of both the Xlink versus Tunnel solution on aredn mesh ?

KN6PLV's picture
Tunnels and xlinks both

Tunnels and xlinks both connect two nodes together, so they're the same in that way. They do it in very different ways that don't really intersect.

Tunnels are a simple to use, all in one feature, which operates over your regular Internet, and connects two AREDN nodes. There's a bit of configuration information to exchange, but it's all fairly easy to setup. They only work over your WAN connection, you use the IP address given by the server, and you don't get much else to configure.

Xlinks on the other hand are much more basic. The configuration lets you pick IP addresses yourself, the peer IP (other end), a VLAN and a port to xlink leaves the device on. The IP addresses let the system route the data (OLSR works at layer 3 so every interface needs an IP address), but unlike the tunnel you can make these anything you want. The VLAN is whatever you need it to be, and the port just let you get the data physically out of or into the device. What happens to move that data to the peer device isn't defined in anyway; and deliberately so. Maybe you want to connect that port directly to a non AREDN PtP setup. Maybe you feed it into a switch then use some other tunneling technology to get it where it needs to go. Maybe its just a bit of ethernet cable. It's entirely up to you.

Personally, I use tunnels to connect nodes over the Internet; but use xlinks to connect nodes over point-to-point radios which aren't AREDN.

Hope this helps a bit.

Tim - KN6PLV

AC2OG's picture

do I need two hAPac2, one on each side of the PtP link, to connect two AREDN mesh islands?
If only one at the near-side-radio, should I simply plug in a cable on the far-side-radio LAN port and connect it to a mesh node on the far island?

Hello Leo, I think the only

Hello Leo, I think the only devices capable of handling a Xlink right now are hAPac2 and hAPac3. The rest can only do the standard DtD link.

AC2OG's picture

Are two hACac2 necessary to construct an Xlink between 2 mesh islands? Could somebody answer my question ?
Thanks a lot for the help. 

nc8q's picture
Both ends of a Xlink require Xlink capable devices

Hi, Leo:

You need 2 from either


  • 2x ac2
  • 2x ac3
  • 1x ac2 and 1x ac3

73, Chuck

Hello, while following

Hello, while following instructions on setting up a tunnel is straightforward I am still a bit confuse when it comes to Xlink. When it comes to configuring a tunnel, one needs to configure server and clients using a set of instructions on public IP, WAN Port and tunnel password. But when it comes to Xlink, there is fiel in advanced network where the administrator will need to manually insert:
1- VLAN number. it shows 20 on the configuration document online.
4- WEIGHT: 1
5- PORT: 3
Now I dont know if I should replace this IP address (  with the IP address of that first ac2 device. Let's say  that the device receives an IP address such as from a non aredn  DHCP that services ip addresses on a PtP link. 
And the PEER IP ADDRESS, could be the IP address of the other ac2 device receives from the same non aredn DHCP. We can say something like for example.
Please check the attached document to see that section that I am refering to.


Image Attachments: 
AC2OG's picture

Thanks, Chuck.
73, Leo

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