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Topic: LAN clients don't see each other but they can access the internet

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Hi all,

I'm a beginner at using OpenWRT but I'm loving it already. Everything is running fine (internet, wifi) on all clients except one thing: the computers running in my LAN (Win 7) don't see each other. Pings to them or between them gives "destination host unreachable". This happens when using either the machine's IP's or their assigned hostnames.

Running Backfire 10.03.1 with LuCI 0.10.0 0 - default settings everywhere except of course for the specific ISP stuff.

What's going on? Thanks!

EDIT:
this has been SOLVED - see below.

(Last edited by valentingalea on 27 Jun 2012, 18:47)

Why must the LAN interface be bridged with the Wireless one?

Also a strange thing: in LuCI web interface they are properly linked by check boxes but in /etc/config/network it's just
option 'type' 'bridge'
option ifname 'eth0'

How does it know who to link with?

Hmm, that doesn't sound right at all.  The default settings should have everything as one big LAN.

Have you checked in Network, Switch to make sure you do not have the ethernet ports tagged to different VLANs?

As for why must the LAN be bridged with the wireless, its not a "must" but its pretty useful as its part of what allows wired and wireless devices to talk to each other as if they are physically connected to the same network.  Technically WiFi is one network and wired is another, bridging allows you to merge them together.

Alex Atkin UK wrote:

Have you checked in Network, Switch to make sure you do not have the ethernet ports tagged to different VLANs?

I'm sorry but I don't know what you mean / where to look.

Here's my entire /etc/config/network

config 'interface' 'loopback'
    option 'ifname' 'lo'
    option 'proto' 'static'
    option 'ipaddr' '127.0.0.1'
    option 'netmask' '255.0.0.0'

config 'interface' 'lan'
    option 'ifname' 'eth0'
    option 'type' 'bridge'
    option 'proto' 'static'
    option 'ipaddr' '192.168.1.1'
    option 'netmask' '255.255.255.0'

config 'interface' 'wan'
    option 'ifname' 'eth1'
    option '_orig_ifname' 'eth1'
    option '_orig_bridge' 'false'
    option 'proto' 'static'
    option 'ipaddr' <redacted>
    option 'netmask' '255.255.255.128'
    option 'gateway' <redacted>
    option 'dns' <redacted>
    option 'macaddr' <redacted>

What kind of device is that?

TP-Link MR3420 which I recently resurrected from brick state by serial link using the 'firstboot' command - now that I think of it, could that be a factor in this?

Paste the output of "swconfig dev switch0 help".

Actually scratch that, was going to determine the needed switch setup, however its already explained in your devices wiki page - see http://wiki.openwrt.org/toh/tp-link/tl- … figuration

Follow that and it will fix your client<>client connectivity.

for reference what I have now:

switch0: eth0(AR7240 built-in switch), ports: 6 (cpu @ 0), vlans: 16
     --switch
    Attribute 1 (int): enable_vlan (Enable VLAN mode)
    Attribute 2 (none): apply (Activate changes in the hardware)
    Attribute 3 (none): reset (Reset the switch)
     --vlan
    Attribute 1 (int): vid (VLAN ID)
    Attribute 2 (ports): ports (VLAN port mapping)
     --port
    Attribute 1 (int): pvid (Primary VLAN ID)

What does it mean:

Also replace the 'option ifname "ethX"' accordingly (eth0.1, eth0.2). The proper ethernet port layout has still to be confimed.

Should I put:

config switch eth0                   
   option reset 1                     
   option enable_vlan 1             
                                     
config switch_vlan
   option device eth0.1          
   option vlan 1               
   option ports "0t 1 2 3 4" 
                                                                      
config switch_vlan         
   option device eth0.2       
   option vlan 2            
   option ports "0t 5"

?

(Last edited by valentingalea on 4 Apr 2012, 16:26)

Just add this (copy verbatim, no other changes required):

config switch eth0                   
   option reset 1                     
   option enable_vlan 1             
                                     
config switch_vlan
   option device eth0          
   option vlan 1               
   option ports "0 1 2 3 4 5"

Nice! Works perfectly!

Thank you very much @jow!

I bricked my MR3420.  The advice given by Jow above conflicts the advice in the wiki for this device.  Can Jow or valentingalea confirm ALL the extra lines needed and ALL the edits needed to get the MR3420 switch working?  Ideally a dump of someone's config code would be great.  Sorry to ask this info, i tried to learn myself but just don't have the knowledge and I cannot keep bricking devices trying out these different methods of advice.  (I will next try the serial unbrick but time for me on this subject is limited).

Can Jow confIrm that

config switch eth0                   
   option reset 1                     
   option enable_vlan 1             
                                     
config switch_vlan
   option device eth0         
   option vlan 1               
   option ports "0 1 2 3 4 5"

are the ONLY additions I need to make to get the switch working?

What about the wiki advice here...  Also replace the 'option ifname "ethX"' accordingly (eth0.1, eth0.2). The proper ethernet port layout has still to be confimed.

There are conflicts on the wiki with this post, I made a brick, please please help me on this open forum.

Many thanks

Jon

(edited to change spelling mistakes)

(Last edited by jonokimber on 16 Jun 2012, 10:37)

jonokimber wrote:

I bricked my MR3420.

I think it's better to explain further - did you unbrick it? how ? what's working and what doesn't.

For me: I unbricked via serial interface, using the 'firstboot' command. After that everything worked, except the local LAN clients couldn't see each other.
I ONLY added those lines suggested by @jow to the original /etc/config/network (you can see the original file in a previous reply)

Thanks Valentin

I bricked it by choosing the wrong setting in LuCI i suppose.  Still learning a lot.

I have a serial cable on the way and hope to be able to debrick soon.  Then i will just keep trying but it's going to be hard work!

Can I fully and finally confirm you did no edits to this line...

option ifname "ethX"' accordingly (eth0.1, eth0.2).

to make your LAN ports visible to each other?

Many thanks

Jon

jonokimber wrote:

I bricked it by choosing the wrong setting in LuCI i suppose.

Ha, me too! smile

Yes, despite what it says in the wiki, I didn't change it. Have faith, use the serial cable carefully and everything will be ok!

Hi Valentin, I spent this evening preparing my MR3420 for debrick tomorrow hopefully.  My eBay Nokia USB - serial cable should come tomorrow, and tonight I did the internal soldering on the main board.  I found an old cable with a male and female 9 pin D-Sub connector.  I cut this in half and will use both ends to make a repeatable and secure connection to my router as i'm sure there will be one or two debricks required!

I used the legs from a spare resistor to make some "easy to solder to" pins on the main board and put a resistor over the outside two pins.

I aim to use the firstboot command if i can but can also use a windows based TFTP server to provide a new code.bin if necessary.

First i think i will get the LAN issue sorted out using the advice from jow, then the USB tethering of my Android phone which I have had working before.

Wish me luck!  And thanks for all the help on here and the web for getting me to a state where I have learnt more and hope to end up with a good solution.

The soldering isn't pretty, but it doesn't need to be...

http://farm8.staticflickr.com/7077/7397429964_30441c346f_z.jpg

Jono

Wow - that's a nice soldering job!

I can't solder so I devised this makeshift contact-connector from a PC power supply cable and some needles. I then had to firmly and steadily press it with one hand on the board, while typing with the other big_smile

I thought if i did a good job i'd only have to use it once.  If i did a temporary quick job i'd have to use it lots!

I'm hoping for a good config and then a rest, to enjoy my new setup.

More news tomorrow, hope you don't mind i hijacked your thread?!

Jono

Same problem here, using same HW and SW. Solved with jow thread. Thanks !
Maybe on new release for MR3420 include this ?

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