New Plusnet router = PS4&XB1 LAN connections fail

[#1]

Double nat issue?
Does your mesh have a router component?

[#2]

The mesh is a TPLink Deco M5 that is a couple of years old now and never caused any issues. There are no wired connections to any nodes apart from the LAN input from the Plusnet router.

[#3]

"So , either it still hasn't got the correct ip or I suppose it's just possible that it wont respond to a ping.

Assuming the pc is windows , try an arp - a , does it list 192,168.1.2 as known ?"

How do I run this? If it is:
arp 192.168.1.2 -a
then it yields:

No ARP Entries Found

[#4]

"So , either it still hasn't got the correct ip or I suppose it's just possible that it wont respond to a ping.

Assuming the pc is windows , try an arp - a , does it list 192,168.1.2 as known ?"

How do I run this? If it is:
arp 192.168.1.2 -a
then it yields:

No ARP Entries Found

[#5]

Just arp - a should list all the entries

[#6]

C:\WINDOWS\system32>arp -a

Interface: 192.168.1.65 --- 0xc
  Internet Address      Physical Address      Type
  192.168.1.254         78-65-59-ae-42-7e     dynamic
  192.168.1.255         ff-ff-ff-ff-ff-ff     static
  224.0.0.22            01-00-5e-00-00-16     static
  224.0.0.251           01-00-5e-00-00-fb     static
  224.0.0.252           01-00-5e-00-00-fc     static
  239.255.255.250       01-00-5e-7f-ff-fa     static
  255.255.255.255       ff-ff-ff-ff-ff-ff     static

[#7]

This is after I've manually allocated 192.168.1.2. to the PS4 and set connection to LAN (which still fails to connect to the internet)

[#8]

Well it obviously still doesnt want to talk to the xbox, very ge!

I notice, rereading the supposed solution I linked to, that one of the steps was to clear the mac address on the xbox before setting static ip and then reverting to dhcp. Did you try that ?

[#9]

Unfortunately you cannot change MAC addresses on PS4s (the device I would like to get working on LAN)...

[#10]

I really dont know what to suggest further. If it was just one device that didnt work , I'd say it was the port on that device, but given that 2 devices dont work , that doesnt sound likely. Again, given that other devices work fine wired to the router, it dowsnt sound like the router. Without some more detailed diagnostics I dont think were going to get any further. 

Do the leds on the ethernet porta on both router and ps4/ xbox show any activity ?

[#11]

Try this (if it's not how they're connected currently): connect both PC and PS4 to 9-port LAN hub, connect 9-port LAN hub to Hub One. Allow PC to get an IP from DHCP, assign an unused static IP in the same subnet (e.g. 192.168.1.2) to PS4, ping PS4 from PC, then check ARP, if PS4 MAC entry doesn't appear, it'd mean something wrong with PS4, cable or 9-port LAN hub. You may want to try another cable even if the current cable works fine on other devices because some devices (including switches/routers) could be pickier than others about cables. I have a long cable that works with one router but not with another (not a crossover vs straight problem).

[#12 · Accepted solution]

Ethernet-based internet is now restored but I can't for the life of me explain why! I began @bbpn 's suggestion of putting a PC and the PS4 on the same LAN connection (i.e. both connected via the swtich) by using an old laptop and even though I didn't swap any ethernet cables out suddenly LAN-based internet was restored to the PS4 (not checked the XB1) and using DHCP assiged rather than static IP. My guess is that it was a dodgy connection although the amount of swapping I did while testing seemed to have conclusively ruled that out. Time to leave it all completely alone and hope that it stays live!

A huge thank you to all that persevered with me on this bizarre tech testing journey.