[Olsr-users] Question about listed HNA networks and "active" olsr interfaces

Eric Malkowski (spam-protected)
Tue Sep 27 14:29:57 CEST 2011

Hi All-

It's been a while since I've posted here and I'm still using OLSR 
0.5.8-r6 (latest stable of that series before 0.6.X came out).
I have a basic question about listing networks as HNA in the config and 
the "Active" interfaces one does OLSR on.

I usually never list a subnet in the HNA list at the beginning of the 
config file AND list the interface that the HNA subnet is tied to for 
"active" OLSR at the end of the file.  I have run into a situation where 
it would be beneficial to do this.  Is it OK to do this?

An example could be like this -- two typical mesh + ap nodes out of 
range of each other but connected with a simple wired interface:

Outdoor node:

ath0  AP network listed only as HNA
ath1  Mesh   (does active OLSR, NOT listed as HNA in config)
eth0  Glue network  (does active OLSR NOT listed as HNA in 

Other node connected by wired link:

eth0  Glue network (does active OLSR NOT listed as HNA in 
ath1  Mesh  (does active OLSR, NOT listed as HNA in config)
ath0  AP network listed only as HNA

I've found that even though the two ath1 interfaces (on same subnet) are 
separated by the wired link, clients on each ath0 networks of either 
node enjoy connectivity everywhere.

What I do is have one of the two nodes act as a convenience DHCP server 
on eth0 so if someone plugs in a wired client, they can get an IP.  If 
internet is available, the default route gets them internet access.  
However since the eth0 network is not listed as an HNA by at 
least ONE of the two nodes, someone on eth0 w/ a DHCP address may not be 
able to get everywhere since only host routes are listed for 

I'd like to simply have each node list their eth0 network as 
an HNA in the config.  Any ideas if this will be a problem?  As I said, 
I normally don't configure an interface for active OLSR AND to be listed 
as HNA in the config at the same time as it didn't seem like the right 
thing to do, but I'm thinking to keep everyone to have full connectivity 
everywhere who might grab an IP from the networks on ath0 or eth0 of 
each node, it would make make sense that the eth0 network is 
listed as HNA in one of the two nodes' config files or both.  The more I 
think about this I would think it should be fine.

I hope this makes sense.


-Eric Malkowski

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