[Cerowrt-users] Setting up bridging and debugging problems with LAN ports with WNDR3800

[Marc MERLIN]

On Sat, Nov 17, 2012 at 03:44:37PM -0800, Marc MERLIN wrote:
> Ok, it's a bit long, sorry, I spent too many hours today trying to fix some
> issues in cerowrt and get bridging working.
> 
> This is cerowrt 3.3.8-26.
> 
> Before I get to bridging, openwrt could get my ethernet LAN ports working if I
> recall correcly, but it seems that cerowrt can't (the WAN port is ok, and so
> is wireless, but none of my LAN ports seem to be able to send IP traffic
> even though I see STP and other traffic from them).
> 
> The first issue is while I had wireless working, wired just wasn't.
> I never got an IP on wired ports, and for that matter when I forced the IP
> on my laptop, I couldn't ping the interface
 
Ok, after a full reset it worked again and I figured out what the problem
is.
If you enable VLAN functionality in network/switch, the LAN ports stop
working even if they are marked as 'untagged' which is the default.
When I used tcpdump, I did look for whether there was a tagging problem,
but the packets didn't seem tagged.
But it gets worse, even after turning vlan off in the GUI
config switch          
        option enable_vlan4k '1'
stays and prevents the LAN ports from working.
Actually, also
        option enable_vlan '0'
needs to be restored and without that line, your LAN ports just will not
work.

That's a pretty bad GUI trap, 4H of my time down the drain :(

> > Question #1:
> What am I doing wrong or how do I debug further?
 
There wasn't much to find, this required wiping everything, starting over, 
taking config diffs, finding the option that broke everything, and further
finding that unchecking the GUI option didn't clean the config file enough
to recover.
 
> > Question #4:
> how do I get debugging/logs from dnsmasq? Is it done through syslog?
 
logread or logread -f

> > Question #5:
> Why can't I get the :81 web interface to respond on its outside IP (kind of
> useful when I'm mucking on the internal one).
> /etc/lighttpd/lighttpd.conf says:
> ## bind to port (default: 80)
> server.port = 81

81 is firewalled off on the ge00 interface.

> > Question #6:
> Why is the admin interface on :81 not using https?

Seems that openwrt didn't seem to hink it was a good idea. 

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/