Nighthawk RAX50 not assigning IP addresses to wired devices if switch/NAS combination is present

[sinr]

I have a Nighthawk RAX50 with the latest firmware that has 2 switches attached to it.

- Switch 1 has 8 devices behind it (various devices)

- Switch 2 has 2 devices (Synology NAS and my laptop)

When the NAS is attached behind switch 2,  after about 2-3 minutes no other wired devices can retrieve an IP address including the devices behind switch 1. Basically all wired devices disappear from the "connected devices" list on the router. When I remove switch 2 outright and connect the NAS directly to the router, everything works fine.

Things I've tried:

- I have made sure that the DHCP server is disabled on the NAS and watched its traffic to make sure it doesn't have a stealth DHCP server. I only see the router serving IP addresses.

- I have tried 3 different brands of switches for switch 2

- I have tried not connecting my laptop so the NAS is the only thing connected to switch 2

- I did not have this problem with my previous router of a different brand

The problem persists and I'm going nuts. Any thoughts or ideas are greatly appreciated.

[sinr · Accepted solution]

Sooooo... I'm just going to kick myself here. I've been using my MacBook to test everything and sniffing traffic to try to figure out what is going on.

When I put the NAS behind the switch and plugged in the switch, my MacBook was also plugged into that switch so it cut over automatically to using ethernet instead of wifi. My MacBook also had bootpd enabled on ethernet for testing some embedded devices; the script to automatically disable it after testing failed apparently. So when the NAS was plugged into the switch and the switch was plugged into the router, my MacBook was giving all wired devices addresses for a completely different subnet.

When I detached the switch with the NAS to remove it from testing, my Macbook switched to Wifi automatically and bootpd didn't serve anything because it was bound to ethernet only.

It was a combination of testing steps (switch attached or detached) and bootpd not having shut down properly though I swore I checked it. Apparently I didn't swear enough.

Sorry to waste everyone's time. Mods should feel free to remove this since it didn't involve the Netgear router in any way. Otherwise feel free to leave it as a cautionary tale: be careful with bootpd. 😄

[microchip8]

what kind of switches are these? managed or unmanaged?

[michaelkenward]

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@sinr wrote:

I have a Nighthawk RAX50 with the latest firmware that has 2 switches attached to it.

While many questions about routers are generic and could be answered anywhere, some things need specialist knowledge.

You might get more help, and find earlier questions and answers specific to your device, in the appropriate section for your hardware. That's probably here:

Nighthawk Routers with WiFi 6 (AX) - NETGEAR Communities

In the meantime you could visit the support pages:

Support | NETGEAR

Feed in your model number and check the documentation for your hardware. Look at the label on the device for the model number.

You may have done this already. I can't tell from your message.

I mention it because Netgear stopped supplying printed manuals and CD versions some years ago and people sometimes miss the downloads.

[michaelkenward]

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@microchip8 wrote:

what kind of switches are these? managed or unmanaged?

---

Good question.

Also, another key question, what is the modem/gateway in front of this router?

[sinr]

They are all unmanage switches:

- Netgear GS308

- TP-Link TL-SG1005D

- Rosewill RC-410LX

I even swapped the switches and put my TrendNet TEG-S16D in front of the NAS and had the same issue. 😞

[sinr]

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Also, another key question, what is the modem/gateway in front of this router?

---

It is an AT&T Fiber BGW320 using IP passthrough to the Nighthawk

[michaelkenward]

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@sinr wrote:

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Also, another key question, what is the modem/gateway in front of this router?

---

It is an AT&T Fiber BGW320 using IP passthrough to the Nighthawk

---

At a quick glance, this describes itself as a "gateway".

Installation question with BGW320 and fiber port on gateway | AT&T Community Forums

To me that says "router". So you have two routers on your network.

I am not familiar with these things. Perhaps IP passthrough takes that into account. If not you may be on "double NAT" country:

What is Double NAT? | Answer | NETGEAR Support

[sinr]

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Installation question with BGW320 and fiber port on gateway | AT&T Community Forums

To me that says "router". So you have two routers on your network.

I am not familiar with these things. Perhaps IP passthrough takes that into account. If not you may be on "double NAT" country:

---

The IP Passthrough essentially removes the BGW320 from the network and exposes the Nighthawk to the internet. The Nighthawk is pulling a public IP address and traceroute shows no hops through the BGW320.

[FURRYe38]

What FW is currently loaded? 

What LAN CAT# are you using throughout the network? CAT6 is recommended. 

So if your have the NG switch in between the RAX and NAS, all devices don't get an IP address from the RAX? 

Something to let us know what works or doesn't:

ISP Modem>RAX><NAS direct to router.

                            ><NG GS308 Switch direct to router<>Wired devices

ISP Modem>RAX><NAS direct to router.

                            >>Wired devices direct to router.

ISP Modem>RAX><NG GS308 Switch<>NAS and Wired devices

ISP Modem>RAX><NG GS308 Switch<>Wired devices, No NAS Connected

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@sinr wrote:

I have a Nighthawk RAX50 with the latest firmware that has 2 switches attached to it.

- Switch 1 has 8 devices behind it (various devices)

- Switch 2 has 2 devices (Synology NAS and my laptop)

When the NAS is attached behind switch 2,  after about 2-3 minutes no other wired devices can retrieve an IP address including the devices behind switch 1. Basically all wired devices disappear from the "connected devices" list on the router. When I remove switch 2 outright and connect the NAS directly to the router, everything works fine.

Things I've tried:

- I have made sure that the DHCP server is disabled on the NAS and watched its traffic to make sure it doesn't have a stealth DHCP server. I only see the router serving IP addresses.

- I have tried 3 different brands of switches for switch 2

- I have tried not connecting my laptop so the NAS is the only thing connected to switch 2

- I did not have this problem with my previous router of a different brand

The problem persists and I'm going nuts. Any thoughts or ideas are greatly appreciated.

---

[michaelkenward]

---

@FURRYe38 wrote:

What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?

See above. Already asked and answered.

Seems to be taken into account.

[sinr]

- FW is V1.0.5.106_2.0.70

- CAT6 everywhere. I made sure of that when I ran it. I tossed all my CAT5 cables years ago.

|| NG between RAX and NAS, all devices don't get IP address

Only wired devices don't get IP addresses. Wireless devices are fine. Wireless routing appears to be unaffected.

|| NAS direct to RAX

Everything works.

|| RAX > NG GS308 > wired devices (except NAS) AND RAX > NAS

Everything works.

|| RAX > wired devices AND RAX > NAS

Everything works. Could only hook up a few devices to RAX. Tried different combinations of wired devices.

|| RAX > NG GS308 > NAS + wired devices

Everything works if they are on the same switch. Tried this with the TrendNet 16-port switch too.

|| RAX > NG GS308 > wired devices (No NAS)

Everything works.

I think I got them all. The moment the NAS goes behind a second switch on the network, it goes awry.

|| RAX > switch > wired devices (no NAS) AND RAX > switch > NAS

Everything borked.

Just upgraded the NAS as well and the problem persists.

---

What FW is currently loaded? 

What LAN CAT# are you using throughout the network? CAT6 is recommended. 

So if your have the NG switch in between the RAX and NAS, all devices don't get an IP address from the RAX? 

Something to let us know what works or doesn't:

ISP Modem>RAX><NAS direct to router.

                            ><NG GS308 Switch direct to router<>Wired devices

ISP Modem>RAX><NAS direct to router.

                            >>Wired devices direct to router.

ISP Modem>RAX><NG GS308 Switch<>NAS and Wired devices

ISP Modem>RAX><NG GS308 Switch<>Wired devices, No NAS Connected

---

---

[sinr · Accepted solution]

Sooooo... I'm just going to kick myself here. I've been using my MacBook to test everything and sniffing traffic to try to figure out what is going on.

When I put the NAS behind the switch and plugged in the switch, my MacBook was also plugged into that switch so it cut over automatically to using ethernet instead of wifi. My MacBook also had bootpd enabled on ethernet for testing some embedded devices; the script to automatically disable it after testing failed apparently. So when the NAS was plugged into the switch and the switch was plugged into the router, my MacBook was giving all wired devices addresses for a completely different subnet.

When I detached the switch with the NAS to remove it from testing, my Macbook switched to Wifi automatically and bootpd didn't serve anything because it was bound to ethernet only.

It was a combination of testing steps (switch attached or detached) and bootpd not having shut down properly though I swore I checked it. Apparently I didn't swear enough.

Sorry to waste everyone's time. Mods should feel free to remove this since it didn't involve the Netgear router in any way. Otherwise feel free to leave it as a cautionary tale: be careful with bootpd. 😄

[michaelkenward]

Stuff happens.