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Rds4640
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New Member

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9 Messages

Tue, Mar 22, 2022 6:00 AM

IP Passthrough Not Working

I had a new fiber install today with a BGW320 gateway. From what I had read I thought it would be a very simple config of the 320. I am connecting the 320 to a Ubiquiti UniFi Dream Machine (UDM) to do the routing.

The UDM was already set up and running on a cable modem.

On the 320 I:

Turned off WiFi

Set passthrough mode to DHCPS-Fixed

Added the UDM MAC address manually (didn't see it in the drop down)

Saved settings

Rebooted 320

I then rebooted the UDM.

The UDM does not see out to the internet

The UDM does not pick up the WAN address. It sees a local 192 address.

I can't figure out why the UDM won't pick up the WAN address from the 320.

Any ideas?

tonydi

ACE - Guru

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8.6K Messages

9 months ago

We've seen repeated instances where the BGW320 responds well to a factory reset (hold reset button in for >15 secs) in this sort of situation.  Speculation is that the NVRAM is corrupted or hold incorrect info in some way.

Note that you'll need to start over from scratch if you do this so other things like any port forwarding, SSID/pwd changes, etc, will need to be re-entered.

Also, if you do the reset and implement IP Passthrough again and still run into problems, power both devices off, power up the BGW and wait for a bit before powering up the UDM.  Sometimes you even need to do this a couple of times.

Rds4640

New Member

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9 Messages

9 months ago

It ended up being a weird MAC address issue with the UDM. The 320 wanted secondary MAC address not the UDM's primary.

JefferMC

ACE - Expert

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30.3K Messages

9 months ago

The 320 wants whatever MAC address the UDM is making the DHCP request with and will communicate with the 320 on.  If the UDM calls that the secondary MAC address, then so be it.

New Member

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2 Messages

8 months ago

I've recently upgraded to ATT Fiber as well and I'm running a UDM (non pro) with a switch and 2 AP's.  I've gone through all of the different blogs and forums on this subject and enabled IP passthrough on the ATT router/modem.  I've verified that the ATT given WAN IP has in fact been "passed through".  I've disabled smart queues, DPI, set MSS Clamping, gone through and enabled 1Gbps on every port in the network, upgraded my UDM and subsequent devices to the latest firmware and am operating on their latest UI.  I still have 900Mbps symmetrical speeds coming into the UDM but I'm only getting roughly 300Mbps Down, and 600Mbps Up on my devices that are hardwired, less for wireless.  Any thoughts?

ATTHelp

Community Support

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204.2K Messages

8 months ago

Let's see what we can do to help you improve the speed of your devices, bmpras.

 

First, be sure to keep in mind that having several devices connected can slow down speed, even on 1G Fiber. In addition to that, each device has a maximum Internet speed it can reach. The rate that you send or receive data can even be impacted by the building you're in. Lastly, here are some of the factors that come into play:

  • Age of wiring inside your building
  • Distance between the gateway and your device(s)
  • The age and type of gateway or router
  • The number of devices connected to the gateway
  • Type of connection used

You can learn more about this topic from our guide on understanding internet speeds.

 

If you don't mind, disconnect all but one of your devices and run a speed test so we can better determine if this is a bandwidth matter, or something else.

 

We'll be awaiting the results.

 

Aminah, AT&T Community Specialist

JefferMC

ACE - Expert

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30.3K Messages

8 months ago

It sounds like you still have something going on that's preventing offloading from working on your Ubiquiti.  With gigabit speeds, you pretty much have to keep the router CPU from having to touch the packets.

Rds4640

New Member

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9 Messages

8 months ago

@bmpras 

I have almost the exact same setup. 


Have you tried to hardwire a device (not the UDM) to the AT&T gateway? That’s just to confirm the speeds to that device are not being slowed. 

New Member

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2 Messages

8 months ago

No but I can run a Speedtest on the UDM and it shows 900 Up Down. 

Rds4640

New Member

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9 Messages

8 months ago

Just to compare apples to apples. The device that you are getting slow speeds on the UDM should be connected to the gateway just to rule out the device.
I’msure your are right but doesn’t hurt to be thorough. 

I think the next step after that would be a post over on the Ubiquiti forum. 

New Member

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1 Message

4 months ago

What is the secondary link you are referring to? I'm running into the same issues and trying to throw everything at it to see what sticks... Any help is greatly appreciated...

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