[OLSR-users] Networking help on Metrix Mark II Mesh nodes

Benjamin Watson (spam-protected)
Wed Nov 15 01:42:27 CET 2006


I've got a small wireless mesh network setup in the following topology:


L1 and L2 are laptops (WinXP with wireless cards), R1 and R2 are mesh
routers with dual wireless cards and an ethernet port (running Pyramid

L1: (gets this via DHCP from AP on R1)
R1(wlan0): (AP)
R1(ath0): (Ad-hoc for link2)
R1(eth0): (gets this via DHCP from router connected to Internet)
R2(wlan0): (AP)
R2(ath0): (Ad-hoc for link2)
L2: (gets this via DHCP from AP on R2)

R1 is connected to the "Internet" via its ethernet port (eth0). R2 is
not connected directly to the Internet (its eth0 port is open).

Link1 and Link3 are 802.11b links where R1 and R2 each have a wireless
card configured as an AP. Link2 is an 802.11a link where a wireless
card on R1 and R2 each are configured in ad-hoc mode with the same

The routing on R1 and R2 is accomplished by running OSLRd on the
radios (ath0) on R1 and R2 responsible for maintaining the link2
connection. I use HNA announcements on R1 and R2 to broadcast
connectivity to LANs (wlan0 AP on R1 and R2) and the Internet (eth0 on
R1 only).

Under my current configuration, L1 is hosting a web server and FTP
server.  L2 is able to ping L1 over the mesh, and can even access the
FTP server on L1 and transfer files.  This is wonderful!

Question #1:

L2 is unable to pull up the default web page hosted on L1. I've
witnessed a successful TCP handshake between the two, but the HTTP
connection is never established.  What might be blocking this?

IPTABLES on R1 is currently setup with default policies to allow
everything, and performs SNAT to the IP on eth0 ( to
facilitate Internet access.  IPTABLES on R2 isn't configured at all
(defaults to allow everything).

This same problem occurs when L2 attempts to access the Internet.  L1
can surf the web with no problems (it can even resolve DNS names). L2,
on the other hand, can't resolve DNS names, but even more, it cannot
pull up web sites on the Internet (by IP address) while having the
capability to ping the Internet IP address.

I've installed Lynx on R1 and R2 to troubleshoot the problem and have
verified that R1 can pull up the web page on L1, but R2 cannot (same
symptom as experienced by R2).  R2 also cannot surf the web, but can
ping Internet addresses (e.g. Google) and get replies.

Question #2:

I mentioned the DNS issue.  R1 connects to a cable/DSL router via DHCP
and obtains all of the DNS settings "automagically", thereby allowing
L1 to do DNS lookups and resolve names.

Does anyone have a link to a HOWTO or advise for getting DNS
information on R2 via R1, thereby allowing L2 to do DNS lookups and
resolve names?

I've done some poking around regarding dnsmasq and the nameservice
plugin to OSLRd, but the combination of the two leaves me scratching
my head and my attempts to configure this have been uneventful.

More information (e.g. routing tables, etc.) available upon request!!!

Thanks in advance, and sorry for the long post!


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