[Solved] RPi3 - Client unable to obtain dhcp lease

[mrboldt]

Raspberry Pi 3
OS: Raspbian, Jessie
SD card: Samsung EVO Plus 32G
Power Supply: 5v@2.4a

1) Cat 5 cable verified good, tested.
2) Router has been rebooted.
3) Another Pi 3 connects to router and receives dhcp leases.
4) Tested with 2 identical sd cards and fresh Raspbian installs.

From the time I first established ssh between the two RPi's, ip address has remained fixed on the same Pi 3. I know because I took notes. ip address has never changed. Can not get a lease from the router.

This issue is at board level not OS.

How do I release the default address?

[FTrevorGowen]

AIUI there is no such thing as a "default IP address" at the hardware/board level. There is a default IP address associated with failure to obtain one by DHCP (as referred to by @DougieLawson in another thread) but, from your comments therein that may not be your issue. However, AIUI, each Pi has a MAC address** (subsequently associated with an IP address by the O.S.) which is (partially) generated by the hardware. If the problem is related to that address then, IIRC, the output of ifconfig should show up (unexpected) differences between that for the "working Pi" and that for the "problem Pi" when booted with the same uSDHC card.
Trev.
** For example I've had a USB-to-Ethernet dongle fail when, for some unknown reason, its "on-board" (in OTP ROM?) MAC address has become "corrupted"

[DougieLawson]

How do I release the default address?

Hit your router very hard and buy a new one. If you're not keen to buy a new router take a look at its configuration pages.

If the RPi has no static address defined in /etc/network/interfaces or /etc/dhcpcd.conf then it MUST be your router doing it.

[mrboldt]

DougieLawson,

"Hit your router very hard and buy a new one...configuration pages".

You are partially correct. In this case it would be hit Network Admin very hard. Much as I would LOVE to do that...

Forbidden to even view network configuration.

Solution:
1) TRENDnet 5-Port Unmanaged Gigabit GREENnet Desktop Metal Housing Switch, TEG-S50g
1) TRENDnet USB 2.0 to 10/100 Fast Ethernet LAN Wired Network Adapter for Macbook, Chromebook, Windows 8.1 and Earlier, Wii, Wii U, Linux, and Specific Android Tablets, ASIX AX88772A Chipset, TU2-ET100

I have full control over static and dhcp addressing, wired and wireless.

The footprint of the un-managed switch is close to that of the Pi. I have a Pi sitting on top of the switch. Effectively giving the Pi 4 useful Ethernet ports (router/AP). Resolved VNC display issues, 1280x800, and router/AP now headless. Now I can start removing Cat 5 cables and the usb to Ethernet adapter.

ufw next.

Need three more Pi's.