Thanks for the reply. The link you gave is on the Crisco site. If the information was not correct it would can been caught by the moderator. So my reaction was wrong.
But I have never before heard of setting the router to an address with 254 on a LAN.
As you already know, if two devices on the LAN have the same IP at the same time, you will have a conflict. So each device must have its own assignment.
On my LAN I set my two slave routers, switches, to a lower address in the accessible range of the gateway router. (Which is usually from 2 to 51 for personal consumer grade routers. Imagine a home network with 50 PCs!)
On my system 192.168.1.1 is the default gateway, DNS and DHCP. The modem is at 192.168.1.254 and can not be changed.
The two other routers are at
192.168.1.10
and
192.168.1.20
Which I had to set manual, directly. After you change the IP of a box you can not get to it unless you use the new IP you just assigned.
The 192.168.1.1 is the address most often used by the main router. But 192.168.1.254 is often the modem address when you have a separate modem.
I would not go against want the guys at Cisco say. But you could try and see if that makes any difference.
If I nan wrong, which I often am, please tell me.