RT-AC66U - Manually Assigned IP around the DHCP list(list limit:32)

[themav]

I recently bought a RT-AC66U to replace my WRT54GS running DD-WRT. My WRT54 was an earlier version with the better specs so it has served me well over the years, but with the ever growing number of devices (both wired and wireless) being added in my house it has been getting a bit buggy and sluggish. Torrent downloads would often cause it to briefly drop all connections. Even after a few resets on it seems like the CPU load was getting too high to often, so I decided it was time.

I went back and forth over whether to get the N66U or the AC66U. Don't really need bleeding edge wireless speed, my whole house is wired so the the ol' LAN cable is still my connection of choice, but I figured for ~$30 for better internal specs was worth the spend from a future-proofing point of view.

I know the N66U can already run DD-WRT but I wasn't sure I really needed it. With the WRT54 it was a no-brainer over the Linksys firmware but in the same respect it seemed to often over complicate things for me. There are a ton of settings I don't need and getting DNS to play nice with Windows DNS was often a PIA. The only thing that I truly wanted was the ability to assign DHCP reservations. When I saw that even the stock firmware had this functionality, I decided to go for the AC66U. I figured someone will eventually figure out DD-WRT for the AC66U, and at that time, maybe I will load it up.

Out of the box I was elated at the improve response time from the AC66U, but the one thing that I did over look with the AC66U stock firmware was the 32 address limit for DHCP reservations. It never crossed my mind as I had over 50 addressed in my WRT54 router. I loaded up Merlin's firmware thinking maybe that would correct the limitation but to my dismay, the limit still remains.

I guess my first actual question is why is there a 32 address limit? What does it stem from? I typically chalk it up to hardware limitations but not when my old WRT54 router was capable of more than 32 addresses. That has always worked flawlessly with it.

So my next question would be is there anything in the works to correct this limitation? I wonder as I have searched the net far and wide the past few days and realized that no one else seems to be complaining about this limit.

For me, I use to maintain order in my little universe. I can group things in ranges by device types (i.e. .1-.9 routers & AP .10-.19 printers, etc. and assign them names that I recognize and easily spot devices that shouldn't be there. I can reimage any pc or tinker with any device and it will always come back to the same address right away since the MAC address never changes.

I guess that raises one more question. In DD-WRT when I assigned a reservation, the LAN status page would show the device with whatever name I gave it in the reservation, but with the AC66U the status page will show the names for some of the devices I have set in the reservations, but with many it show a name that it is apparently pulling from the device itself or just displays the MAC address in the name column. Why isn't the name listed in the reservation taking precedence over everything else? I suspect DD-WRT was doing this through the Masq option available.

Thanks in advance.

 

[mikeg]

Regarding the limit in DHCP reservations , have you looked in the LAN - DHCP Server settings where you can assign IP Pool Starting Address and
IP Pool Ending Address ? I myself has the rane of 192.168.x.2 to 192.168.x.254 .
Further down on gui you have Enable Manual Assignment where
you can Enable Manual Assignment and make the assignments you want using the MAC.addresses.

I recently bought a RT-AC66U to replace my WRT54GS running DD-WRT. My WRT54 was an earlier version with the better specs so it has served me well over the years, but with the ever growing number of devices (both wired and wireless) being added in my house it has been getting a bit buggy and sluggish. Torrent downloads would often cause it to briefly drop all connections. Even after a few resets on it seems like the CPU load was getting too high to often, so I decided it was time.

I went back and forth over whether to get the N66U or the AC66U. Don't really need bleeding edge wireless speed, my whole house is wired so the the ol' LAN cable is still my connection of choice, but I figured for ~$30 for better internal specs was worth the spend from a future-proofing point of view.

I know the N66U can already run DD-WRT but I wasn't sure I really needed it. With the WRT54 it was a no-brainer over the Linksys firmware but in the same respect it seemed to often over complicate things for me. There are a ton of settings I don't need and getting DNS to play nice with Windows DNS was often a PIA. The only thing that I truly wanted was the ability to assign DHCP reservations. When I saw that even the stock firmware had this functionality, I decided to go for the AC66U. I figured someone will eventually figure out DD-WRT for the AC66U, and at that time, maybe I will load it up.

Out of the box I was elated at the improve response time from the AC66U, but the one thing that I did over look with the AC66U stock firmware was the 32 address limit for DHCP reservations. It never crossed my mind as I had over 50 addressed in my WRT54 router. I loaded up Merlin's firmware thinking maybe that would correct the limitation but to my dismay, the limit still remains.

I guess my first actual question is why is there a 32 address limit? What does it stem from? I typically chalk it up to hardware limitations but not when my old WRT54 router was capable of more than 32 addresses. That has always worked flawlessly with it.

So my next question would be is there anything in the works to correct this limitation? I wonder as I have searched the net far and wide the past few days and realized that no one else seems to be complaining about this limit.

For me, I use to maintain order in my little universe. I can group things in ranges by device types (i.e. .1-.9 routers & AP .10-.19 printers, etc. and assign them names that I recognize and easily spot devices that shouldn't be there. I can reimage any pc or tinker with any device and it will always come back to the same address right away since the MAC address never changes.

I guess that raises one more question. In DD-WRT when I assigned a reservation, the LAN status page would show the device with whatever name I gave it in the reservation, but with the AC66U the status page will show the names for some of the devices I have set in the reservations, but with many it show a name that it is apparently pulling from the device itself or just displays the MAC address in the name column. Why isn't the name listed in the reservation taking precedence over everything else? I suspect DD-WRT was doing this through the Masq option available.

Thanks in advance.

 

[themav]

Regarding the limit in DHCP reservations , have you looked in the LAN - DHCP Server settings where you can assign IP Pool Starting Address and
IP Pool Ending Address ? I myself has the rane of 192.168.x.2 to 192.168.x.254 .
Further down on gui you have Enable Manual Assignment where
you can Enable Manual Assignment and make the assignments you want using the MAC.addresses.

The manual assignments is the section that I am referring to that has the limitation of only 32 addresses. (Sorry I was refering to them as reservations instead of manual assignments; the Windows server world calls them reservations.)

My DHCP range is set from 192.168.x.150 to 192.168.x.250. That is plenty of addresses and I have no problem connecting as many devices as I want to the network but I want to force devices to take a specific address between 192.168.x.2 to 192.168.x.149 based on MAC address as to organize them in sequence based on device type and give them names. If you try to add more than 32 entries in this section, it will not let you. This is the main issue that I am having as I was able to add as many as I liked in DD-WRT on my old WRT54GS.

 

[RMerlin]

The 32 IPs limitation is probably for performance reasons. Increasing this isn't as simple as just raising the limit, it would also require going over all the firmware code to ensure there is no buffer that could be overrun by increasing this limit. That's not in my plans at this time, sorry.

32 static IPs for a home router should be plenty enough. If you need more, personally I think you should consider having either a business-class device, or running a server with its own DHCP server. You shouldn't need static leases for mobile devices such as phones or tablets, for instance. Static IPs are usually meant for device that host some service, and therefore requires to be reachable through a fixed IP.

 

[kfmfe04]

Resurrecting an old post, asuswrt-merlin 3.0.0.4.270.26 on my N66U shows:

Manually Assigned IP around the DHCP list (list limit:128)

That leads me to suspect that if RMerlin hasn't played around with that part of the code, in all likelihood, an update to the firmware (even from ASUS) should give you what you are looking for, especially since AC66U is the next model up.

 

[RMerlin]

Resurrecting an old post, asuswrt-merlin 3.0.0.4.270.26 on my N66U shows:

Manually Assigned IP around the DHCP list (list limit:128)

That leads me to suspect that if RMerlin hasn't played around with that part of the code, in all likelihood, an update to the firmware (even from ASUS) should give you what you are looking for, especially since AC66U is the next model up.

I increased various limits to 128 in 270.26. Asus has also increased various values in either 354 or 364, but they only increased them to 32 or 64 (I forgot).

 

[x46085]

List limit > 200?

Any plans in the works for the limit to be raised over 200? I acknowledge that I'm a unique user in this regard, but I love this firmware, and suddenly have a need to statically assign 200 IP's by MAC address. If this is unlikely, could you point me in the direction of setting up my own DHCP server that works with this router as you described pursuing? Thanks again!

 

[RMerlin]

Any plans in the works for the limit to be raised over 200? I acknowledge that I'm a unique user in this regard, but I love this firmware, and suddenly have a need to statically assign 200 IP's by MAC address. If this is unlikely, could you point me in the direction of setting up my own DHCP server that works with this router as you described pursuing? Thanks again!

That definitely won't happen. If your network requires 200+ static reservations, then you are doing something wrong in your network planning, quite frankly.

 

[elorimer]

I'm curious about one thing, and I'm replying here only because if I google that thing, this is the first hit.

Like the OP, I assign static IPs in groups by device with familiar names, from around .2 to .164. My DHCP range is .16 to .254. Even though some of my IPs are in that range, and some are out, everything seems to work fine.

What does it mean that the manual assignment table is labeled "Manually assigned IP around the DHCP list"? Is it better/necessary for the manual assignments to be inside, or outside, the DHCP range or does it not matter?

Just curiousity.

 

[zoldy]

if your looking at setting 200 reservations run a DHCP server on a windows computer. or other. If you use windows server DHCP is simple and reservations are easy. If not using windows server just google DHCP server and there are plenty out there.

then just disable DHCP on your router. the only disadvantage of course is your windows box will need to be on all the time.

hope that helps.

Comment though - why not just set static IP addresses on your devices? Much easier.