[OLSR-users] Willingness not taken into account in route table

lolo (spam-protected)
Tue Apr 12 17:10:29 CEST 2005

Hi Frédéric

Frédéric DELAUNAY wrote:
> on node, olsrd-gui in MAIN display as MPR. And 
> effectively all trafic goes through 10.0.3.x. When I disconnect 
> 10.0.3.x node, trafic goes though 10.0.2.x, but as soon as I replug 
> 10.0.3. trafic goes back to that node.
> is that a bug ?
No. It's rfc3626 compliant ;-)

Here is a summary of the routing table construction as stated in the 
oslr rfc (chapter 10)

0- Erase routing table
1- Add neighbors found in neighbor table in routing table.
    hop count = 1
    no MPR here
2- For each two hops node found in 2 hops neighbour table that is not 
    registered in the routing table, add that node if it's corresponding 
    node is already present in routing table and the willingness of that 
    is not WILLNEVER.
    hop count = 2
    no MPR here
3- For each entry T_dest_addr (a MPR selector) found in topology table,
    where T_last_addr (a MPR of the network seen as a whole, original 
sender of
    a TC message) is already in the routing table, add T_dest_addr, with 
the same next
    hop used to join T_last_addr in routing table
    hop count=3
    no MPR as next hop
4- repeat step 3 incrementing hop count until no more element is added 
in routing table.

At step 1 you add neighbors
At step 2 you use those one hop neighbors to join two hop neighbors as 
next hop
At step 3 you use the information sent from MPRs to join the rest of the 
network, using
the already present nodes in routing table as next hop.

No willingness to chose (except from WILLNEVER), no necessary MPR as 
next hop

So data packets could end up travelling all the way up to the far end of 
the ad hoc network
on roads with no MPR at all as relay



PS : Andreas, or any of the olsr "guru" presents in this list, don't 
hesitate to correct any
of my statements if i missed something

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