NatThreshold here is a nice new small feature in olsrd: keeping the routes to a default gateway sticky.

Now, what do we mean by that?

Imagine you are running a mesh network with private IPs (192.168.x.x) and this network has multiple gateways. For example you share many DSL uplinks. There is a well known problem with olsrd in these settings: if one route to a gateway becomes better than the previous route to a different gateway, then the route will switch. This is a bit of a problem if the gateways NAT for you. In other words: your downloads will suddenly stop.

Now there is a solution for this: NatThreshold.

Just add for example

NatThreshold 0.5

to your /etc/olsrd.conf

What does it do?

Well , in case the new route to a different gateway is double as good as the old route than the old route , olsrd will switch.
If you have NatThreshold 0.3, then the new path needs to be 3 times as good for a switching, etc.

So basically the path to a default gateway "sticks" to the default gw.

This should eliminate most of the nasty side effects of gw switching. Have fun & feed back improvements and bug reports please.

Labels: olsr nat

  ¶ 4:13 PM 0 comments