DHCP not working from ASUS router through ASUS bridge

[Nicholas Eubanks]

RESOLUTION FOUND:
The issue is the shortfalls of the DHCP server capabilities of either the Hardware or Software of the ASUS AC3200 or AC66U. After purchasing an ASUS AC5300 and installing it as the HUB/DHCP router, I am now getting DHCP addresses assigned for all devices. Every once in a while there will be a small lag of <10 secs in the issuing of an address, but it has not failed yet. It has been running for nearly a week.

I loaded windows server 2012 R2, with a student license on a PC I use for projects, and It was able to effectively issue DHCP addresses for all network devices that requested them.

Okay, this may get lengthy to describe as I will also define all attempted fixes and solutions I have attempted to resolve my issue. This issue concerns wireless bridging of routers as well as several access points. I have seen one other similar post here that refers to what I am doing, but the workaround that resolved his issues are not applicable in my situation. The post I am referring to is HERE.

To begin I will describe my network layout so that you may get a general idea of what is setup and where the hardware lies along with overall distances. All IP address for routers are statically set.
The hardware involved is as follows:
2x ASUS AC3200 (stock firmware)
6x ASUS AC66U (stock firmware)
8x ASUS N66U (stock firmware)
1x ZyXel ADSL MODEM

HUB:
I have a Hub location where the wireless signal is broadcast from one ASUS AC3200 over 3 TP-Link Omni Antennas at 12dBi and one Parabolic Dish Antenna at 24dBi
IP= 192.168.1.1

ECC:
The second location is a community center that has the other ASUS AC3200 router that has one TP-Link Dish antenna just like the HUB and pointing (laser assisted setup, clear line of sight through a lightly forested area) at the HUB, typical reported connection speeds can vary between 150MB/s to 300MB/s and 4 or 5 bars depending on weather. The ECC is located about 900FT away and is the furthest wireless connection. The ECC has two access points coming off the bridges ac3200. Both APs are ASUS N66U's

PLEASE NOTE, sharing internal IP addresses is not a security risk and I am posting this from work, so my connected address is not my ISP address... just in case someone wants to say something about sharing IP addresses.
IPs:
Bridge = 192.168.1.3
AP 1 = 192.168.1.13
AP 2 = 192.168.1.23

CLIENTS:
There are 6 client locations that also bridge to the HUB via ASUS AC66U's with an AP that is an ASUS N66U. These range in distance from 100ft to 600ft. Wired methods are only plausible for three of these 6 locations, but not doable at the moment.
IPs:
CLIENT1:
ASUS AC66U Bridge = 192.168.1.2
ASUS N66U AP = 192.168.1.12
CLIENT2:
ASUS AC66U Bridge = 192.168.1.4
ASUS N66U AP = 192.168.1.14
CLIENT3:
ASUS AC66U Bridge = 192.168.1.5
ASUS N66U AP = 192.168.1.15
CLIENT4:
ASUS AC66U Bridge = 192.168.1.6
ASUS N66U AP = 192.168.1.16
CLIENT5:
ASUS AC66U Bridge = 192.168.1.7
ASUS N66U AP= 192.168.1.17
CLIENT6:
ASUS AC66U Bridge = 192.168.1.8
ASUS N66U AP = 192.168.1.18


Now that this is defined, here is my issue. DHCP Server is not issuing addresses BEHIND the wireless bridges. If I set a static IP address then 3 out of 4 times the device will connect with no issues. But if I connect a device to the HUB wireless network the client will get a dhcp address with no issues and connects just fine. I attempted to setup all devices on the same table ( all 16 devices within a 6 foot radius of eachother) and configure the bridges one at a time, but they still presented the DHCP issue.
What I have attempted:
Warranty replacement of hardware.
Firmware both old and new
Merlin firmware
DD-WRT firmware (not applicable for AC3200's, not available.)
Connecting just one bridged router
Static IP's do not always work, but typically do
DHCP address range is set to 192.168.1.200-254

I do not think that the issue is based in the bridges/APs as they all exhibit the same issue, unless it is a firmware/hardware limitation that I am unaware of.

EDIT: STATIC IPs work EVERYTIME for a device that is wired directly into the APs or Bridges, Wireless STATIC IPs are finicky, and DHCP is almost non existent.

Question:
Would I have more luck with using a different subnet (255.255.0.0)? Then setting each bridge/AP on it's own subnet? With every device powered on and connected I will not have more than 60 devices connected.

Device counts: 54 Total
16 Mobile phones
4 Tablets
4 Desktop PCs
15 Laptops
5 TVs
3 printers
1 roku
3 xbox's
2 playstations
1 WiiU

 

[Nicholas Eubanks]

Thanks for the move, My apologies for posting in the wrong location.

 

[Nicholas Eubanks]

And the title change... lol

 

[Puppa]

@Nicholas Eubanks You are correct: the problem is with the main router, not the access points. If I replace my main router with a non-ASUS solution, DHCP works across all access points. If I replace my Access Points with non-ASUS access points, problem still occurs.

You have a large network. It stretches the bounds of what is a home network. I see the issue intermittently (yet often) with 20 devices. The lower the traffic, the less I see the DHCP problem. But it doesn't take much traffic to make the problem happen. In fact, if my son is playing Xbox at all, and one other device is streaming Hulu, I cannot get a DHCP address if I try to attach to the network or renew. Existing addresses still function, however.

I have seen the router completely ignore or take more than a minute to provide a DHCP address. Something is very brittle about the implementation. Even with my Mikrotik CCR1016-12G, I see a delay in DHCP, though nowhere near the problem I get with the RT-AC3200 as my DHCP server. When I get the RT-AC5300 (arrives today) I'll see if the extra 40% cpu clock is enough to solve the issue. I may wind up using these only as Access Points (and 3200 even has issue just with that).

 

[Nicholas Eubanks]

@Puppa I would rather not put a full blown server up there with the router as the shed is an uncontrolled environment and the air is not cleaned of dust/contaminants like inside a home or office, and I don't have the money to spend on a server and software. But I do have a raspberryPi I am not using and I just checked for a DHCP solution for it, and found THIS. I will work on this solution this evening and can post back with my results.

Thank you for the quick response as well, It has been painstaking to find any other resources that have issues similar to my own.

 

[Nicholas Eubanks]

Alright.

So after a weekend of messing around with this stuff, I have been unable to resolve the DHCP issue completely, but there was a weird exception. If I connected my phone, xbox, PC, or other device to one of the bridged networks via the 5GHz band, the device connected and obtained a valid DHCP, sometimes (if i released and reconnected) from the routers DHCP address range (192.168.1.100-199) and sometimes from the PI DHCP address range (192.168.1.200-254). But if a device connected via the 2.4GHz band, it would nearly always fail to connect and obtain a DHCP address. So setting up the PI as a secondary DHCP server worked, but not entirely...

EDIT: The weird thing about the phones connecting on the 2.4GHz band is that they would not even attempt to connect. I would enter the password and select connect and it wouldn't even try and connect, it just says saved. I can select the network as many times as possible and it does not try to connect.

I doubt this exception can be explained, as the devices are connecting to the same hardware, just over a different bandwidth. I can also say that there is no other wifi networks for about 15 miles around us. We also do not own an microwaves that may cause interference. We do have aluminum roofing, and other appliances though.


Found THIS thread concerning my question below, but my situation is still somewhat unique of this thread. Essentially the HUB Router will service 7 wireless clients(bridges), but those bridges will then be feeding the rest of the traffic.

I will be researching on my own, but I am going to ask the question below:
So, and I don't know if this is the best forum to ask this on, With a budget of around $800, what would someone suggest I get on a business grade level router that can offer at least four antenna ports. I am not really worried about speed ATM as I would rather have a working network to reduce the amount of mobile data the rest of my family use ( about $600/month ). I am servicing up to 60 devices and 22 people. If the router can handle HD streaming from a media server (PLEX), that's a plus but not required. My ISP connection is a shabby 12MBits or ~1.8MBytes (wonderful rural DSL). And if the router can handle two plus ISP connection, that would be great too, as I am looking into getting a second line run and maybe put my grandfathered Verizon unlimited data connection up there as well. Two DSL lines at $75 each is still cheaper than mobile data for everyone else.

Anyways, Thank you for the input @Puppa , and thank you in advance anyone that can offer assistance.

 

[Puppa]

You're certain that AP Isolated is not checked in the Wireless settings, correct? I have, btw, had failures of DHCP on 5GHz as well, but I'm starting to suspect there is something going on with my 3200 hardware : I can no longer achieve uplink throughput over 5 Mbps (often it is 0.1Mbps), regardless of settings or if only one device is attached (even with firewall off, radios off, and wired connection). Going to try to get it back to factory settings including nvram later.

Sent from my SM-N920V using Tapatalk

 

[Nicholas Eubanks]

@Nicholas Eubanks You are correct: the problem is with the main router, not the access points. If I replace my main router with a non-ASUS solution, DHCP works across all access points. If I replace my Access Points with non-ASUS access points, problem still occurs.

You have a large network. It stretches the bounds of what is a home network. I see the issue intermittently (yet often) with 20 devices. The lower the traffic, the less I see the DHCP problem. But it doesn't take much traffic to make the problem happen. In fact, if my son is playing Xbox at all, and one other device is streaming Hulu, I cannot get a DHCP address if I try to attach to the network or renew. Existing addresses still function, however.

I have seen the router completely ignore or take more than a minute to provide a DHCP address. Something is very brittle about the implementation. Even with my Mikrotik CCR1016-12G, I see a delay in DHCP, though nowhere near the problem I get with the RT-AC3200 as my DHCP server. When I get the RT-AC5300 (arrives today) I'll see if the extra 40% cpu clock is enough to solve the issue. I may wind up using these only as Access Points (and 3200 even has issue just with that).

Any update on the RT-AC5300?

 

[Nicholas Eubanks]

You're certain that AP Isolated is not checked in the Wireless settings, correct? I have, btw, had failures of DHCP on 5GHz as well, but I'm starting to suspect there is something going on with my 3200 hardware : I can no longer achieve uplink throughput over 5 Mbps (often it is 0.1Mbps), regardless of settings or if only one device is attached (even with firewall off, radios off, and wired connection). Going to try to get it back to factory settings including nvram later.

Sent from my SM-N920V using Tapatalk

I believe it is not selected, but I will confirm when I get home this evening.
I can connect with almost no issues to the 5GHz band, the 2.4 is where my issue lies. And I need the 2.4 for 4 of my 6 media bridges as they are to distant for 5GHz to reach.

I am also going to swap out the AC3200 with an AC86 that I have to see if the issue persists.
I will report back with those findings tomorrow.

 

[Nicholas Eubanks]

The check box is not selected for isolated AP. I also had issues with connecting to the 5GHz band last night while I was testing stuff.
I did not get to swapping out the routers last night though, so I will plan on doing that this evening time willing.

 

[Nicholas Eubanks]

Reporting back. Swapping the routers has yielded no results. The DHCP issue is still present.

I am now setting up a windows server (using a student license) to see if using this as my primary DHCP server will resolve the issuing of addresses.

Again, I will report back when I have determined the results of this project or if someone else responds with a suggestion.

 

[Puppa]

Been running for a week with the 5300 on .753 and AC68U on .1031 in media extender mode. No DHCP issues. This has NEVER worked this long for me, so maybe the issue has been fixed, deliberately or incidentally. If you decide to buy a 5300, please don't feed the scalpers. It should be $399 (USA price).

Sent from my SM-N920V using Tapatalk

 

[Nicholas Eubanks]

Okay. Running the DHCP server has fixed my DHCP issues. Unfortunately this is not a long term fix, but has confirmed the anythe pre-AC3200 has issues supplying DHCP addresses to more than ~20 or so clients. Whether it is a software or hardware limitation, I could not tell you. Before I invest the money into an AC5300, Can you tell me @Puppa if the antenna are swappable? I will need to be able to use my TP-Link antenna to keep my setup going.

 

[Puppa]

Any update on the RT-AC5300?

I have been running the 5300 fw753 with a 68U in Media Bridge mode with fw1031 for about 3 weeks now, never a single DHCP problem, so something has changed with recent drivers/chipset I think. In fact, I haven't had any problem of any kind since setting up the 5300/68U pair. I also no longer see slow grants of DHCP addresses, which occurred frequently on my 3200.

 

[acnoob]

I just had the same (or similar) issue on my Linux box connected to the AC88U, which is a bridge to an AC5300. After running "sudo dhclient -4 -v eth0" and waiting for about 5 minutes, I eventually got an IP address. This is long beyond the time I would normally wait for an IP address to be given.

 

[Puppa]

@acnoob Sounds like the bug is still present in the 380.xxx firmware. What version firmware on each device?

Sent from my SM-N920V using Tapatalk

 

[Nicholas Eubanks]

I have been running the 5300 fw753 with a 68U in Media Bridge mode with fw1031 for about 3 weeks now, never a single DHCP problem, so something has changed with recent drivers/chipset I think. In fact, I haven't had any problem of any kind since setting up the 5300/68U pair. I also no longer see slow grants of DHCP addresses, which occurred frequently on my 3200.

I can also attest that the AC5300 has overcome the shortfalls of the lower class consumer routers. I have purchased and install an ASUS AC5300 and have no issues with DHCP address requests/assignments. Every so often the will be a slight lag of less than 10 seconds for a new device connecting but this is only the case when more than 32 devices are actively connected to the network through any of the APs. I have had zero lag in the issuance of DHCP addresses when connecting directly to the ASUS AC5300s wireless network. I found one new on eBay for $360 too. I also added the as the resolution to my first post so anyone might see that and just jump in and buy one. It was worth the investment.

@Puppa, I will have to check my firmware when I get home, but I can confirm that there is sometimes a delay in the DHCP issuance, but has yet to fail. *My delay has never been more that 10 seconds though*

 

[Puppa]

Yes, I've seen the short delay too when Xbox game is in progress plus 3 devices streaming HD video, but delay is only a few seconds at most. I haven't seen 10 seconds, but I have 28 devices connected now at most.

Sent from my SM-N920V using Tapatalk

 

[Nicholas Eubanks]

When nobody was on during my setup and testing phase, there was no delays. The more users that connect though, the longer the delay gets. It isn't bad seeing as this thing wasn't built with the intent of running a large range of devices, but at least it gets the job done. I appreciate your feedback @Puppa with your experience with the AC5300. I just hope that this thread will help someone else down the road if they experience the same thing. On a side note, the longest I have waited was about 8 secs and that was about the same for every mobile device that was looking to connect, any of the PCs though haven't hit over 5 seconds. The fact that it is longer on the mobile devices, both android and ios based may be due to the coding used in the software or the chipsets they have themselves.

I will say though the the connectivity speed and overall range that is broadcasting has increased by nearly 50%. A location about 1200ft away that normally saw no signal now gets about a 2 bar average, while the furthest location, about 900ft, typically got 3 or 4 bars now holds steady at 5 bars and 300MBs connection speed.

 

[acnoob]

@acnoob Sounds like the bug is still present in the 380.xxx firmware. What version firmware on each device?

AC5300: 3.0.0.4.380_753
AC88U: 3.0.0.4.380_664