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

[Marc MERLIN]

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

Since I can't get a DHCP answer on LAN, I forced an IP:
gandalfthegreat:~# ifconfig eth0 172.30.42.4 netmask 255.255.255.224
gandalfthegreat:~# ping 172.30.42.1
PING 172.30.42.1 (172.30.42.1) 56(84) bytes of data.
>From 172.30.42.4 icmp_seq=1 Destination Host Unreachable
11:21:05.175560 ARP, Request who-has 172.30.42.1 tell 172.30.42.4, length 28
11:21:05.763975 IP 172.30.42.1 > 224.0.0.1: igmp query v2
11:21:06.171874 ARP, Request who-has 172.30.42.1 tell 172.30.42.4, length 28
11:21:06.365442 IP 172.30.42.1 > 224.0.0.251: igmp v2 report 224.0.0.251
11:21:07.171869 ARP, Request who-has 172.30.42.1 tell 172.30.42.4, length 28

This shows that my laptop sees traffic from 172.30.42.1 but won't get an ARP
reply.

Then from my router, I tried to ping my laptop and got this:
12:51:29.954271 ARP, Request who-has 172.30.42.4 tell 172.30.42.1, length 46
12:51:29.954294 ARP, Reply 172.30.42.4 is-at f0:de:f1:f6:03:80, length 28
12:51:30.130065 IP 172.30.42.1 > 224.0.0.13: PIMv2, Bootstrap, length 36

This shows my router is sending an arp, my laptop gets it, replies, but
the reply isn't making it to the router.

So it seems that inbound traffic on the router's LAN ports isn't working.
Is it a bug/misconfiguration with the switch chip (rtl8366s) that breaks only IP
and somehow seems to ignore/discard arp queries too?
I looked in firewalling and didn't see anything obviously wrong.

> Question #1:
What am I doing wrong or how do I debug further?


Then, ignoring the LAN ports for now, I got bridging to work like this:
brctl addbr br-lan
brctl addif br-lan  se00
brctl addif br-lan  sw00
brctl addif br-lan  sw10
brctl setpathcost br-lan se00 5
brctl setpathcost br-lan sw00 15
brctl setpathcost br-lan sw10 10
ifconfig se00 0.0.0.0
ifconfig sw00 0.0.0.0
ifconfig sw10 0.0.0.0
ifconfig br-lan 192.168.206.249
brctl stp br-lan on
brctl show
bridge name	bridge id		STP enabled	interfaces
br-lan		8000.2cb05da0c8a4	yes		se00
							sw00
							sw10

This is working and I can switch between the 2 wireless interfaces without
dropping a connection, but
> Question #2:
How do I get this saved properly in the cerowrt config so that it's not overwritten
by the UI when I touch anything at all, and of course lost at boot.
(if I had a 2nd router with openwrt it'd be easier since I could see how
they save their bridging config)


> Question #3:
I had to hand edit /var/etc/dnsmasq.conf to get DHCP working with the new
data after boot (and restart the daemon). 
Should I save stuff in /etc/config/wireless somehow? but if so, I'm not sure
what syntax to use for the bridge config.

> Question #4:
how do I get debugging/logs from dnsmasq? Is it done through syslog?

> 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

## bind to localhost (default: all interfaces)
#server.bind = "localhost"

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

Thanks,
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/