OSPF, aggregation and multiple links

RouterOS Wireless Networking
1

We would like to establish a routed wireless network with OSPF to use aggregation and failover (as explained in http://wiki.mikrotik.com/wiki/OSPF_to_simulate_full_duplex_links_with_redundancy
The final network will be the one enclosed (see picture).
By summarizing we will have:

  • 3 sites, each one with 2 dual radio units

Every link must be online and balance traffic (so at the best 4x bandwidth by using direct and indirect links from site3 to site1) coming from Site3 (video streams, etc.). Site1 is the central station (PCs that decode video streams).
If, for example, direct link between site1 and site3 goes down, all traffic must be redirected through site2.
We don’t know how to setup such a system…
Any help is much appreciated!
Thanks!
BondingFailover.png

2

You should put 1 router instead of a Layer 2 switch, (i think a RB 450 should work, or a 493AH if you need more eth) link them via wireless (bridge,wds) then config OSPF on the routers.
Make the traffic move in one direction only with path costs (Clockwise maybe) and you have the max throughput for a 3 sites network.
OSPF will ensure the failover.
About configuration, you might need a consultant tho..

3

We are willing to use RB433; ethernet switches are there only to connect ethernet interface of RB433, PCs, video encoders, etc.
My doubts are:

  • do i have to mark packets ?
  • OSPF has to be redistributed over wlan1, wlan2 and ethernet on all RB433 ?
  • do i need Layer3 switches instead of layer2 switches?
4

I have used essentially this exact setup many times and it works wonderfully.

http://forum.mikrotik.com/t/nstreme-link-scenario-and-questions/19094/15

for this to work correctly, Bridge NOTHING! (every interface on the Mikrotik routers in this config should be routed and running OSPF, except maybe the one plugged into the switch. Ensure all OSPF interface costs for your ethernet interfaces all match, all receiving side wlan interfaces match (but must be higher then the transmitting side , and all transmitting side wlan interfaces also match. This will create the full duplex routing you are looking for.

duplicate this config for maximum reliability and performance, or to save some cost, put 2 radio’s in each RB and run both sides of the link over one board, and then aggragate the links to each site into a router as shown (you will have to keep them very far apart on the channel seperation)

5

Hi Forepoint
thank you very much for the explanation.
When all links are physically up (I mean ideal environment), I think that the best route is chosen based on path costs, isn’t it? So for example site3 to site1 directly and site2 to site1 directly. What if the bandwidth between site2 and site1 isn’t enough and I need to redirect some video streams coming from site2 through site3? Do I have to do it statically? In what way?
Is it possible for you to send me your ospf configuration?
Thanks!

6

I too would like to see your setup. I have implemented this and got it working but I had to route 2 different networks on either side of the ethernet ports. I do not see how (as in the wiki) to route the same subnet across the wireless links. Thanks!