No DHCP through Wireless Bridge

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Earbanean

344 posts

Ultimate Geek

# 209148 14-Mar-2017 16:59

I have recently upgraded my Netgear WNDR3700 router to an Edgerouter Lite and I have WiFi through a pair of Cambium E400 APs. I now want to re-purpose the Netgear as a 5.0 GHz wireless bridge to a Sony stereo in our kitchen. The stereo has 2.4 GHz WiFi built in, but we have problems with that due to the proximity of the microwave. So I want to connect it via ethernet to the Netgear, then back to the E400 via 5.0 GHz WiFi.

I've tried setting this up on the Netgear using both DD-WRT and Gargoyle firmware and testing with a laptop connected via ethernet to the Netgear. But in both cases the laptop cannot get an IP from the ERL through DHCP. I've followed the set up instructions for the bridge client and with a manual IP set on the laptop, it can connect back to the ERL no problem. But when I set it's IP to auto, it can't connect.

I've searched Gargoyle and DD-WRT message boards without finding a solution. It seems some other people have struck the same problem, but haven't appeared to solve it. With the exact same Gargoyle or DD-WRT settings that work for some people, for others the DHCP doesn't work. So it sort of seems it's related to something different on the main router/AP side of the set up.

So, I'm wondering if anyone could shed some light on why the ERL isn't successfully giving the bridged laptop an IP. Is there maybe some way to debug DHCP?

The test set up is:

ERL-----E400 - - -(WiFi) - - -WNDR3700-----laptop

Goosey

1856 posts

Uber Geek

Subscriber

# 1736469 14-Mar-2017 19:22

so you have definatley turned off DHCP on the netgear right?

Earbanean

344 posts

Ultimate Geek

# 1736489 14-Mar-2017 20:05

Goosey:

so you have definatley turned off DHCP on the netgear right?

When it's in Client Bridge mode (in Gargoyle) that's done implicitly for you. There's no place to switch on/off or configure DHCP.

sbiddle

28363 posts

Uber Geek

Moderator

Trusted

Biddle Corp

Lifetime subscriber

# 1736512 14-Mar-2017 20:37

It is working as a true L2 bridge passing the correct MAC address from behind the bridge being passed through and not the MAC address of the itself itself?

Earbanean

344 posts

Ultimate Geek

# 1736545 14-Mar-2017 22:04

sbiddle:

It is working as a true L2 bridge passing the correct MAC address from behind the bridge being passed through and not the MAC address of the itself itself?

It doesn't seem to be doing that correctly. The ERL can't see the MAC of the laptop, but it seems to be giving an IP address to the Netgear. So it would appear the bridge is not working correctly. But I'm pretty sure I configured it exactly as instructed. Also, I've tried it with both DD-WRT and Gargoyle and with both firmwares I get the same problem.

rhy7s

362 posts

Ultimate Geek

# 1736579 14-Mar-2017 22:27

Is it not possible to just use a static IP if that's working? Or do you not have that option on the stereo? Does the stereo need to be in the same subnet to access services on your LAN? Or is just access to the web required? If so, could the Netgear just be run as a router so that its WAN interface is via WiFi and it'll hand out addresses to clients on its ethernet ports if you need DHCP?

Kiwifruta

1054 posts

Uber Geek

# 1736598 15-Mar-2017 04:16

I had a similar problem and resolved it by setting the DNS in the bridged router (the Netgear in your case) to point to my main router (your ERL).

Earbanean

344 posts

Ultimate Geek

# 1736656 15-Mar-2017 09:07

rhy7s:

Is it not possible to just use a static IP if that's working? Or do you not have that option on the stereo?

Yep, that's probably possible. I really want to see if I can get the bridge working "properly", but failing that, it'll probably be good enough just to set the stereo IP manually. It'll be the only client using the bridge.