[CUWiN-Dev] hsls routing multihop

[Gurung, Provin [IE]]

I am having some multihop routing update problems with HSLS.

Here it is:
I have three single interface nodes, X, Y, Z, on a wireless LAN and the
connectivity among them is as follows:

X--Y--Z 

i.e. Link between X and Z multihops through Y.

In this setup the routing table on X and Z are correct :
On X it says nexthop to Z is through Y 
On Z it says nexthop to X is through Y.
On Y it says X & Z are on the local subnet (nexthop = 0.0.0.0)

Now after the first configuration when I put all of them in one broadcast
LAN then the multihop routes disappear and the routes to Z from X (and to X
from Z) show as local subnet routes -- as expected.

Now if I revert back to the first configuration (i.e. one of multihop nodes)
than the routing table never gets updated, i.e. routing table on X continues
to show Z as directly connected, even though the routing table should have
said that the node is reachable only through Y.

Btw I modified the HSLS to run on Linux, so I am not sure if the problem
that I am seeing is related to a bug in my porting or in the original
source. I tried to dig into the source, to see how are the routing
difference calculated in the file hsls_spf.c but had trouble figuring out.
If BSD HSLS does not have the above mentioned problem, then could someone
please let me know what is the logic used when calculating routing deltas.
If the problem is in the BSD version then can someone let me know if a fix
would be available anytime soon.

One more question, In the HSLS document from BBN I think it mentioned that
HSLS routes are not to be deleted if a node does not hear from its peers,
but rather the increase the metrics to a high number. Does the HSLS
implementation do that or does it just delete the routes?


Thanks for help,
-Proveen