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New Member

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4 Messages

Wednesday, June 23rd, 2021 10:48 PM

Cascade Instructions (LAN to WAN) for AT&T Fiber BGW320-505 To Second Router With Public Static IP Block

I'd like to cascade the BGW320 into my other router that's set up behind it, including managing a block of public static IPs I got. My understanding of what I'm trying to accomplish is to make the BGW320 as hands-off as possible so that the UDMP can manage the firewall and all traffic. I can find instructions for IP passthrough and other bits and pieces of things I need to consider. But I think the public static IP block adds a layer of complication. I've read that I should NOT do IP Passthrough and instead do the cascading thing. Again, I'm not sure and nothing walks me through the entire process that I can follow. I'm new to this stuff and I'm hoping someone can dumb it down enough for me to understand.

Here's what my setup looks like right now:

AT&T Fiber Internet --> BGW320-505 --> Unifi Dream Machine Pro (UDMP) <-- All other devices

  • Nothing else is connected to the BGW320 aside from the UDMP (LAN to WAN). That is, an RJ-45 cable is plugged into one of the BGW320's ethernet ports, and the other end is plugged into the "internet" port of the UDMP.
  • The only adjustments I made so far is to disable the BGW320 wifi so as to not interfere with the UDMP wifi access points.
  • As mentioned, I bought a block of 5 usable static public IPs from AT&T. But I'm not sure how to utilize these. The info the AT&T tech provided looks like:
    • Gateway IP XX.XX.XX.206
    • Subnet Mask XXX.XXX.XXX.XXX
    • IP Range XX.XX.XX.201 --> XX.XX.XX.205

If your network is working fine why do you want to do any of this?

I'm going down this road because I was trying to set up a Plex server. I ran into a "double NAT" issue and nobody outside my home network can access my Plex server. I think the double NAT issue will be resolved by cascading the routers.

Why did you buy public static IPs?

Also because of the Plex server. I thought these were needed to facilitate connecting to the server and that one of these static IPs would be assigned to it. Clearly I'm confused about this. I got it in my head that the UDMP would get one of the public static IPs and then the Plex server gets another one? Or maybe I'm supposed to assign static public IPs to all three devices in question (BGW320, UDMP, Plex server)? I'm really not sure. Currently the Plex server is connected to the UDMP like any other device.

What is your Plex server?

I bought a Synology DS920+ NAS. It has a built in OS that can install Plex onto itself. Setting up the hardware was fairly easy. And like I said, devices within my network have no problems streaming from the Plex server right now. External connections -- say, a friend with the Plex app on their TV -- can see my Plex libraries on their side but cannot stream anything. Ultimately this is what I'm hoping to resolve.

Thanks in advance for any help offered. Let me know if there's any other info or screenshots or pictures I can provide. I'm outside my comfort zone here but am very excited to learn how to do all this.

Community Support

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232.3K Messages

2 years ago

Hello @wsggsllc

 

 

I can give you call now.

 

 

 

 

Lisa
AT&T Business Social Media

Community Support

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232.3K Messages

2 years ago

 

Hello @wsggsllc

 

I called twice and no answer. Please let us know when you have time for a call. Thank you, Lisa

 

 

Lisa
AT&T Business Social Media

New Member

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17 Messages

2 years ago

Hi Lisa. If you can give me an email or text with some notice, I can be available. Or can you can preschedule any time tomorrow (Friday)?

New Member

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17 Messages

2 years ago

Hi Lisa. If you can give me an email or text with some notice, I can be available. Or can you can preschedule any time tomorrow (Friday)?

New Member

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17 Messages

2 years ago

@JefferMC - FWIW, I finally reached an engineer in ATT "fiber support". He was not a fan of the cascaded router config and he said the only solution to avoid a double-NAT was IP passthrough. I was able to briefly test before my window elapsed and did not see the hop from the BGW private network. I will try again next weekend and hopefully setup VPNs and move to Prod. I may have to burn another firewall if I want  internet-facing hosts too, but that's a secondary objective.

ACE - Expert

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35.6K Messages

2 years ago

I am not a cascaded router fan, either.

If you're willing to buy the public static block, and don't have to directly address multiple devices behind your router, then I'd just use the Public Static setup.  That gets around use of the NAT table in the Gateway, but leaves the hop.

IP Passthrough gives you close to the same effect, but you do have the NAT/session table but not double NAT.

(edited)

New Member

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2 Messages

2 years ago

I'm sorry to tag onto this post, but this setup is exactly what I need.  I followed the instructions given at the post from AT&T "Configuring IP Passthrough and DMZplus", but no matter what - my UDMP always gets a private IP (192.168.1.68 currently).  I have rebooted everything, and double-checked the passthrough settings.  

Any advice? 

Thanks in advance.

ACE - Expert

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35.6K Messages

2 years ago

It can take a while for the UDMP to successfully obtain the WAN IP address via DHCP.  My suggestion would be to double check the settings, then unplug the Gateway and UDMP.  Plug the Gateway in and let it boot up.  Wait 5 minutes or so, then plug in the UDMP.  Check its WAN IP.  If it still doesn't work. repeat.  If that STILL doesn't work, then:

1) Change the Passthrough mode from DHCP-Fixed to Manual.

2) Change the WAN IP of the UDMP to the WAN IP of the your Gateway from the Broadband Status page.

3) Change the Default Gateway of the UDMP to what the Gateway shows under Broadband Status page.

4) Change the SUBNET mask on the UDMP to 255.255.252.0 

5) Save those settings and reboot the UDMP

(edited)

New Member

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2 Messages

2 years ago

@JefferMC Thanks for your response.  Indeed, after powering down, waiting 5+ minutes, and restarting everything 3 times, the BGW was still giving me a private IP.  I changed to manual and was able to get it working properly! I will just have to remember that if the internet ever inexplicably quits working, it may be because the BGW got a new public IP and I'll update the UDMP. 

Thanks again!

New Member

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1 Message

2 years ago

@JefferMC  can you give me a IM? I am in a similar config situation as OP, but with a different wanted outcome and would greatly appreciate your assistance. My main problem is that the BWG320-500 doesnt support more than 16 static mapped devices and i have way more device statics i need mapped and am trying to passthrough to a PFsense router to attempt to let it do the mapping of the statics. 

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