Hello,

What are my options to connect two sites with layer 2 capability mikrotik is only on one site?

A customer requires us to establish a GRE tunnel with L2 capability. My idea was to create a simple GRE tunnel, and add a GRE interface to a bridge with some ethernet interface. But it looks that I cannot add GRE to bridge. Manuals for GRE are not usefull at all.

I need to establish a L2 and pass through DHCP requests & traffic.


Any ideas?


Mitja

GRE is a routing protocol. On Layer 3, Not Layer 2.
It is compatible with Cisco GRE. Actually Mikrotik GRE is compatible with Cisco GRE, because Cisco developed this protocol.

For Layer2 tunnels you need 2x Mikrotik because they have EoIP tunnel interface as option.
So if you have any other brand than Mikrotik in you tunnel L2 will be no option!

I advise you to look at the DHCP Relay option in the Mikrotik if you need that de DHCP request must be served at a central DHCP sever. Please keep in mind that because of the L3 tunneling both sides of the tunnel must have different subnets!

GRE is a routing protocol. On Layer 3, Not Layer 2.
It is compatible with Cisco GRE. Actually Mikrotik GRE is compatible with Cisco GRE, because Cisco developed this protocol.

For Layer2 tunnels you need 2x Mikrotik because they have EoIP tunnel interface as option.
So if you have any other brand than Mikrotik in you tunnel L2 will be no option!

I advise you to look at the DHCP Relay option in the Mikrotik if you need that de DHCP request must be served at a central DHCP sever. Please keep in mind that because of the L3 tunneling both sides of the tunnel must have different subnets!

Thank you.

Yes, I am aware of dhcp-relay, I am actually using it in my network but it still isn't an option as this customer requires L2 not just for DHCP.

So in theory I could be doing:
1. L3 with GRE
2. Routing (OSPF/...) over GRE
3. MPLS/VPLS L2 Tunnel over GRE

Thank you.

Yes, I am aware of dhcp-relay, I am actually using it in my network but it still isn't an option as this customer requires L2 not just for DHCP.

So in theory I could be doing:
1. L3 with GRE
2. Routing (OSPF/...) over GRE
3. MPLS/VPLS L2 Tunnel over GRE

Indeed if both sides support MPLS of VPLS you should be able to make a Layer 2 network over the GRE tunnels. You can use static routes or OSPF if you like. Be ware of the fact that GRE is not encrypted! So in case you need secured tunnels use ipsec for encrypting your GRE tunnels.

I do not have any practical experience with MPLS or VPLS buth so I can not advice your any further on that subject.
If you need more info on GRE tunnels with routing in combination with ipSec, please feel free to ask me.

This one was easy. It actually works.

For future reference:
1. Establish a GRE tunnel as per WiKi:
http://wiki.mikrotik.com/wiki/Manual:Interface/Gre

2. Establish MPLS/VPLS tunnel over the GRE, check this one:
http://wiki.mikrotik.com/wiki/Transpare ... using_MPLS

...and it works.

Can You guys help me establish L2GRE tunnel with microtik router RB750Gr3.
I am working in order to make it establish connection to our WAG and kinda hoping it helps tunneling the L2 traffic to it.