Question Why isn't a headless Raspberry Pi 5 visible on LAN when Xfinity gateway is in bridge mode?

[nohoudini]

I have an ASUS RT-AX55 router and an Xfinity Gateway (Cox Technicolor CGM4331) in Bridge Mode.
NETGEAR 8-Port Gigabit Ethernet Plus Switch (GS308E)

LAN - [switch] - [router] - [Xfinity Gateway (bridge mode)]

9 clients, ethernet connected unless WiFi indicated {

1 Smart Security Hub (WiFi, visible)
2 active laptops (visible)
1 tablet (WiFi)
3 streaming devices {
Onn (WiFi, visible)
Xumo (visible)
Roku (not visible)
}

1 printer (WiFi, not visible)
2 Raspberry Pi Zero 2 w (visible)
}

All of these devices can access the internet with bridge mode on or off.
I can print from all applicable devices.
I can ssh to the Pi zeros.
I can remote from either laptop to the other.

The Pi 5 is only visible when the gateway is not in bridge mode.

 

[evermorex76]

You didn't list where the Pi 5 is connected or how. What does "not visible" mean, exactly? Are they all connecting solely to the wired or wireless coming from the Asus router or the switch? How are you using a Cox-owned modem with Xfinity? Is the Pi 5 getting an IP address that is in the same subnet as all the other devices?

 

[Ralston18]

What IP addresses and subnet masks are you using?

Update your post to include some sort of line diagram or other representation of your network.

Diagrams and screenshots can be posted here via imgur (www.imgur.com > green icon " New post".

More information needed.

 

[nohoudini]

You didn't list where the Pi 5 is connected or how. What does "not visible" mean, exactly? Are they all connecting solely to the wired or wireless coming from the Asus router or the switch? How are you using a Cox-owned modem with Xfinity? Is the Pi 5 getting an IP address that is in the same subnet as all the other devices?

The PI 5 is connected through the switch.


Not visible means the device is not on the Asus device list, but it is on the network and functioning.


4 devices are connecting wirelessly; 5 devices are connecting via the switch.


The Xfinity Android app says "Your TECHNICOLOR CGM4331COM is online."

https://www.cox.com/residential/support/technicolor-cgm4331.html


I don't know what address the PI has been assigned, it isn't showing on the asus device list.
Also it's headless, the address defaults to Dynamic IP. It appears to boot normally,
the LEDs are not flashing any error codes.

 

[evermorex76]

Cox just happens to use Technicolor and provides a support page for it for their customers. It is a brand used by most cable ISPs. Cox doesn't produce them.

Who cares whether the Asus shows it in the device list if it's working perfectly fine? And if it's on the network and functioning, then I'd assume you're able to remotely access it, so you must know what IP it has. If you can't get into it, how do you know it's working or has booted normally?

The connected devices/network map list in an Asus router isn't 100% accurate; it's a proprietary feature and nobody outside Asus knows what criteria it's using to "find" them, and it's known to have devices randomly missing from it. Sometimes refreshing repeatedly will change the list, sometimes a reboot of the router does the job. Sometimes they'll just appear on their own briefly then go away. There's no way to know why it works when bridge mode is off but not when it's on. (What subnet do you have the router set to for the LAN side, and what IP does it get on the WAN when bridge mode is off?)

The DHCP client list will show what IPs have been assigned to what devices. You can also just try ping scanning the entire subnet range with Advanced IP Scanner, if in fact you don't know the IP, as long as the Pi5 is configured to respond to ping. (It will also test some common ports so it might be identified even if it doesn't respond to ping. Advanced Port Scanner can go further.)