[Olsr-users] Routing-Problem | olsr.org - 0.6.0 | weight | etx_ff | mode ether

[Michel Blais]

In those case, I use LinkQualityMult to unpriorise a link.

On router C

Interface "wan"
{
         Mode "ether"
}

Interface "vlan4"
{
         Mode "ether"
         LinkQualityMult default 0.2
}

Do the same for the interface on the same subnet than vlan 4 on router 
A3 and this link cost will be mutiply by 5 for this up.

if you use 0.5, link cost will be multiply by 2.

This often happen when the're no traffic on A link and b link have some 
paquet lost.

If paquet lost for B link is too much and cost more then 3 then it will 
try link A. If the're no traffic on link B then cost come back to 2 so 
it goes back to B.

One feature missing on OLSR would be a time to live for this. If olsr 
try a link and that it's worst then the other, then it should no try it 
back untill TTL reach 0. That would be a lot better than link cost 
manupulation with LinkQualityMult. I know that OLSR was not built with 
this in mind but for fixed wireless link, that would be great. We see 
this problem a lot as a WISP.

Michel Blais

Le 2012-03-29 09:56, Michael Rack a écrit :
> Dear olsr-users!
>
> I have a bad behavior and hope to get some help.
>
> I run only P2P Links (AP & STA) via wireless-lan and direct ethernet 
> connections. Every node runs currently olsr version 0.6.0.
>
> The Problem:
> I have several upstreams and like to define which upstrem to be used 
> via the weight parameter. In previous versions of olsr this worked 
> fine (as i can remember v0.5.5). Now it dosn't.
>
> My Settings:
>> Willingness             3
>> LinkQualityLevel        2
>> LinkQualityAlgorithm    "etx_ff"
>> UseHysteresis   no
>> TcRedundancy    2
>> MprCoverage     1
>>
>> InterfaceDefaults
>> {
>>         Ip4Broadcast   255.255.255.2555
>>         HelloInterval   2.0
>>         HelloValidityTime   60.0
>>         TcInterval  5.0
>>         TcValidityTime  120.0
>>         MidInterval 5.0
>>         MidValidityTime 120.0
>>         HnaInterval 5.0
>>         HnaValidityTime 120.0
>> }
>>
>> Interface "wan"
>> {
>>         Mode "ether"
>>         Weight 10
>> }
>>
>> Interface "vlan2"
>> {
>>         Mode "ether"
>>         Weight 2
>> }
>>
>> Interface "vlan4"
>> {
>>         Mode "ether"
>>         Weight 5
>> }
>
> But currently the wan-interface is selected. While everything goes via 
> "wan" the routing change to "vlan4" but after a few minutes the 
> routing switch back to "wan" and i get a bad packet-loss for 4 seconds 
> while the routing is switching back to "wan" - but i don't know why 
> because both links are up and running. I don't know where the packets 
> get loosed.
>
> Currently Network-Design:
>
>>           INTERNET-ROUTER
>>                  |
>>       / ------- / \ ------- \
>>    ROUTER A.1           ROUTER B.1
>>       |                     |
>>    ROUTER A.2           ROUTER B.2
>>       |                     |
>>    ROUTER A.3               |
>>       |                     |
>>       \ --------\ / ------- /
>>         "vlan4"  |   "wan"
>>               ROUTER C
>>                  |
>>               ROUTER D
>>                  |
>>                CLIENT
>
>
> MTR is done via ROUTER D and the internet. The routing decision is 
> made on Router C that is multihomed (A.3 & B.2).
>
> So what have i to do, to make WEIGHT working?
>
> Liebe Grüße aus Freilassing,
>
> Michael Rack
> RSM Freilassing