Use ClientID instead of DUID in dhcpcd requests

[prenetic]

• With DUID, new DHCP leases would be issued upon reboot when paired with DHCP servers that respect DUID, instead of reusing the existing DHCP lease.
• The MiSTer installation process now generates a random hardware address, so DUID is unnecessary. Including DUID results in wasted leases within a DHCP scope, and can also lead to DNS resolution issues when accessing the device.
• More details
  • Wifi randomly pulls a second 169 IP, causing all internet connections to fail post-boot Linux-Kernel_MiSTer#29 (comment)
  • Wifi randomly pulls a second 169 IP, causing all internet connections to fail post-boot Linux-Kernel_MiSTer#29 (comment)
  • https://misterfpga.org/viewtopic.php?p=74311#p74311

This change has shown to be helpful for those affected by the issue. For cases where DUID is not respected by the DHCP server for DHCPv4 requests, this change has no impact.

Diff after change:

diff dhcpcdOLD.conf dhcpcdNEW.conf 
11c11
< #clientid
---
> clientid
16c16
< duid
---
> #duid

[birdybro]

Just to add a little context for one thing, the random pulling of an APIPA address to a second interface has been occurring since before the change that added the randomization of MAC addresses.

[sorgelig]

• With DUID, new DHCP leases would be issued upon reboot when paired with DHCP servers that respect DUID, instead of reusing the existing DHCP lease.

do you mean MiSTer WiFi will get new IP with every reboot? Doesn't sound good.

[sigboe]

I also experience this issue with my Mikrotik router, if I set a static IP for MiSTer on the router, it is not respected. And I can have multiple dhcp leases active if I reboot multiple times in the same day. In limited testing this also solved the problem for me

I can't use mdns over vpn, and It takes time to update to the new IP if I am on the same network (there is probably a way to make that go faster? But shouldn't need to do that)

[prenetic]

• With DUID, new DHCP leases would be issued upon reboot when paired with DHCP servers that respect DUID, instead of reusing the existing DHCP lease.

do you mean MiSTer WiFi will get new IP with every reboot? Doesn't sound good.

That is the current behavior when paired with routers/DHCP servers which respect DUID, every reboot results in a new lease because the DUID.

This change corrects that behavior to ensure existing leases are reused upon reboot by removing the DUID from the DHCPv4 request.