How to route route via two different links between common end points

RouterOS Forwarding Protocols
1

Dear Gentle Folk,

I am a newbie to ospf and its use over complicated loopy networks.

Presently we have 5 sites connected via mikrotics and ubis as follows:

FV -------------------------------------CH-----HT
| ------- WV --------AX ---------------|

What this says is that there are two routes from FV to HT,

1.) Internet → FV → CH → HT

2.) Internet → FV → WV → AX → CH → HT

The downstream from FV to CH is full, so traffic from FV → HT is having problems.

The upstream from CH → FV is almost empty.

The downstream AND upstream from FV to WV → AX → CH is almost empty.

Since all of HT is on its own subnet, on FV I have a ‘route HT via WV’ sending downstream packets from FV to HT via WV rather than CH. It is expected those same packets come back via CH.

This works for a few minutes then starts to fail.

All miks are running OSPF with each of their neighbors.

The OSPF on WV shows two gateways for HT:

HT: FV,AX ether1, ether3 cost 40

It is true that packets can go from WV to FV to CH to HT, but FV has a hard route for those
packets back to WV, so a bounce back and forth starts between FV and WV and the packets go nowhere.

What is the correct way to send packets destined for HT through WV? Its ok if they come back via CH.

Beyond that since I have two routes from FV to CH, whats the best way to load balance
everything going between those two sites automatically?

Thanks in advance,

Homer W. Smith
CEO Lightlink Internet

2

There are several ways to achieve the load balancing you want. All of them have tradeoffs so be aware that you will likely have to trade simplicity for functionality when you need to solve network problems. They are listed from easiest to hardest:

  1. Artificially set the OSPF cost so the network paths appear to be equal
  2. Use policy routing
  3. Use BGP instead of OSPF since it can apply policies to manage traffic paths
  4. Traffic engineering tunnels
3

in my opinion in your design right now policy routing is the best option