Verizon FiOS → [Networking] 2 additional routers question

I have successfully added an Asus AC1900 router as my "wifi" router. I connected lan-lan, disabled DHCP, configured wifi to be the same as the Fios router and set the starting IP to 192.169.1.2. I disabled wifi on my latest gen Fios Actiontec (the one with the red band around the front) and it all works perfectly. Now, I would like to run another Asus to another remote part of my house. Do I do the same as above but change the IP to 192.168.1.3? is that the only difference?

Hi,
Assuming you are using ethernet, that should work fine. Just use fixed but different wifi channels and the same SSID(s).
EDIT: Did you shrink the DHCP range on the primary to 192.168.1.10-.254?

I did not shrink the HDCP range on the primary (that being the Fios router, I am assuming). Do I have to? If I disable DHCP on routers 2, 3 etc, what does shrinking it on the Fios one give me?

Hi,
I am not 100% certain, but it is the recommended method, I think the idea is to avoid DHCP errors assigning the same IP to more than one device. It is pretty easy to do. Or try it without and see if it works.

OK, that maybe makes sense. I actually set this up earlier this week and had a problem, hense this post. The Fios router went crazy. i.e not working at all. Would this be caused by DHCP errors? With only 1 extra router, it all works fine without shrinking DHCP or so I have found in my house.

The only reason to change the DHCP range is to have some IP's for setting a static IP assignment which is useful if you plan on using a few routers within your network. To make managing those device easier to remember. i.e. keeping router A as 192.168.1.1 then router B as 192.168.1.2 and so on.. Be sure to disable the DHCP server on the additional routers to avoid double nat'ing and other weird issues that can happen from assigning the same ip

I did disable DHCP on routers 2 and 3 and all seemed OK for 1 day. Wifi was very strong and the Fios router seemed to be flashing away at full speed, working hard. All I didn't do was shrink DHCP on the fios router. Fios is 1.1, Asus 1 is 1.2 and Asus 2 is 1.3. Do I HAVE to shrink DHCP on the Fios one now?

I don't know for sure, but I have seen the same recommendation in more than one place and it is really pretty simple to do....why not follow the recommendation and try it. The thing about DHCP errors is that they can have numerous symptoms, the main one being that various devices can't connect to each other or the internet. It's your call, but if you start having strange issues again, I would do it for sure. Good luck

As mentioned by others, strongly recommended.

If device B has a static IP address (e.g. 192.168.1.2), the primary router has no DHCP lease with that device and is essentially unaware that device B is using that address.

When you use static IP addresses, you take responsibility for your netowrk configuration and not having duplicate addresses.

Now device C comes along and wants a DHCP address. Device C sends a DHCP Discover request. The primary router looks at its DHCP pool. If the pool starts at .2, it very well may return a DHCP Offer response of 192.168.1.2 Oops, that's in use by device B. Now you have two devices with the same IP address.

This is also the reason that you don't want two DHCP servers on the same subnet. Doing so isn't illegal, but unless you know what you're doing, it best to avoid the situation.

That makes absolutely perfect sense. Thanks for the explanation. Now, if only I could fine that damn setting to shrink it. I'll search on here.

Can you point me to the router menu where I shrink this please?

Hi again,
Go to My Network, click on Network(HomeOffice), lower right settings, down towards the bottom, "Start IP Address".....

Thanks. I found it and changed it. I appreciate the help.

If you have a router that is assigning duplicate IP address then that router needs to be thrown in the trash. I have never seen that with any of the routers I have used or the DHCP servers I used in the 90's and early 2000's at home.

For any static IP addresses I use DHCP reservations. My current router allows for 64 reservations. So 64 of my devices have reserved IP addresses and the rest are automatically assigned by the router.

I currently have over ninety devices on my home network. In the last twenty years I have never seen a duplicate IP address with DHCP reservations. The routers will not let you assign the same IP address twice. If they do then they need to be trashed.

Hi aaronwt,
Thanks for your opinion. I think that the crux of the problem is that when following the guides for this type of setup, you seldom see more information than is necessary to complete the task. Some folks using these guides don't really appreciate the difference between setting a given device up with a "static" IP, vs going into the primary router and "reserving" an IP. My recollection is that the guides don't get into "reserving" IP's at all, just setting the static IP but "protecting" it by placing it outside of the regular DHCP pool. Part of this may be because when using a secondary router as just an AP, the default IP on the AP may be either the same as the primary, or on an entirely different subnet altogether and in either case, the secondary AP will need to be setup with a static IP other than the default. To go back to the primary and then "reserve" that IP for the AP is an additional, and possibly confusing step, for someone with less experience than you. If someone just follows the guides then but doesn't place the IP outside of the regular DHCP pool, it is quite possible that when say power goes out and back on, as the various devices reboot and IP's start getting handed out that some other device could be assigned to the same IP as the "static" set on the AP. The guide recommendation prevents this without needing to reserve IP's on the primary router.

The guides were originally written using a Rev.A, and maybe much later using a Rev.C when the first one died. Firmware revisions permit newer features, and I don't recall the availability of DHCP reservations at that time. Or maybe they were there, but I didn't pay as much attention. While working out the procedure from scratch many times to verify the instructions, there were innumerable reboots.

One other factor when I work with my network, is I want to assign IP addresses to certain fixed devices. So my networked printer, the secondary Actiontec, the Slingbox, the Moxi DVR and my primary desktop pc get static IPs. Much harder to achieve consistent addressing after a hard reset on the router than to assign true static addresses after changing the DHCP scope.

Just saying why I wrote what I did. I tell my friends there's a method to my madness. They say luckily theirs doesn't have to match mine.