RT-N66U + Motorola SURFboard + Charter Communications = fail

[RMerlin]

BTW, one more question. What was the rate in these older firmware versions. Your previous post:



makes me think the default was "Aggressive". But was the old Aggressive the same as the new? Or did they make it even more aggressive and just add the less aggressive "Normal" setting for the situations where the ISPs required it?

Aggressive mode is the exact same timing as the previous default timings, while Normal is the relaxed one (required by Charter).

 

[F5ing]

Aggressive mode is the exact same timing as the previous default timings, while Normal is the relaxed one (required by Charter).

Thanks. Either Cox has implemented something similar to Charter or it was a one time incident where the modem's indicator LEDs didn't reflect the true status of the connection (I've been messing with cable modems on the Cox network for 10 years or so and I don't recall that ever happening).

Still have DHCP mode set to normal though, and have had no issues (12+ days) so I don't have any reason to switch back to aggressive mode.

 

[huck344]

3.0.0.4.276 is not the latest FW - the latest is 3.0.0.4.374.

Thank you Merlin. I didn't realize that. When I would click the check for updates, it told me that I had the latest version. Anyway, I downloaded direct for the ASUS site. Hopefully, this will help.

Thanks again!

 

[MattErickson]

I have this issue as well ...

I have a Motorola SB6141 cable modem and an Asus RT-N66U router ... both brand new off Amazon. I upgraded the Asus firmware to most recent version 3.0.0.4.374_979. Here is what I experience:

2-5 times a day I cannot access the internet from the Asus router for 2-5 minutes. I can wirelessly access the Asus config pages (so wireless connection is working). I can access the cable modem status page. (so connection between the router and the cable modem is working). There are no error messages in the log files on either the router or modem. The modem is not losing connection to the provider (Time Warner) and this was also confirmed by Time Warner support. The modem is not rebooting or doing a DHCP renew. I can see those events in the log on the router when they happen normally. I do not see any errors in the logs during these outages. The "ping" tool on the Asus page does not respond to pings to google.com during these outages.

During the outage if I connect my laptop via ethernet cable directly to the modem I can use the internet normally. When I reconnect the router it doesn't work.

Strange as it seems the Asus router is losing the ability to "see" outside the WAN.

Any ideas? I just set the DHCP from Aggressive to Normal ... but based on the lack of DHCP log messages on the router I don't think this is the issue.

 

[jds685]

I have a Motorola SB6141 cable modem and an Asus RT-N66U router ... both brand new off Amazon. I upgraded the Asus firmware to most recent version 3.0.0.4.374_979. Here is what I experience:

2-5 times a day I cannot access the internet from the Asus router for 2-5 minutes. I can wirelessly access the Asus config pages (so wireless connection is working). I can access the cable modem status page. (so connection between the router and the cable modem is working). There are no error messages in the log files on either the router or modem. The modem is not losing connection to the provider (Time Warner) and this was also confirmed by Time Warner support. The modem is not rebooting or doing a DHCP renew. I can see those events in the log on the router when they happen normally. I do not see any errors in the logs during these outages. The "ping" tool on the Asus page does not respond to pings to google.com during these outages.

During the outage if I connect my laptop via ethernet cable directly to the modem I can use the internet normally. When I reconnect the router it doesn't work.

Strange as it seems the Asus router is losing the ability to "see" outside the WAN.

Any ideas? I just set the DHCP from Aggressive to Normal ... but based on the lack of DHCP log messages on the router I don't think this is the issue.

I'm in a very similar situation to you, but don't have a solution. I have the same cable modem but using the Asus RTAC66U router with Charter. I've tried everything I can think of and can't find a solution. I, too, have changed to normal from aggressive mode.

Charter came to my home after I called them and it turns out their signal and the modem are just fine. If and when the router loses the connection with the modem, it will not automatically reconnect. It must be done manually.

So there are two issues - (1) the fact that it disconnects and (2) the fact that it won't reestablish a connection.

Very frustrating! I'm looking into new routers...

 

[bobbarkney]

I have the same setup SB6121 & RT-N66U. I also have my old D-Link 624. Hooking the SB to the Asus unit fails, the Link light stays blue instead of turning to yellow. But if I hook the D-Link to the modem, and the RT to the D-Link, everything is fine. My reset interval (the time to power off everything and power up) is some 2-4 minutes. I even hot-swapped from RT to D-link, and the modem light instantly changed to yellow.
My conclusion -- the Asus is simply not compatible with the SB. Of course, I could fight the situation, but I think I'll just return the Asus. So for you are struggling on this, ask around to borrow some clunker router and see if that is a quick fix.

 

[sgtduckyboy]

I'm in the same place!

I have tried everything to include getting a new one. bottom line Charter Cable Modem works with dlink router and any computer without any issues. but when I plug in my Asus router the same thing as you guys get, no connection between the router and the modem. if I try the wait 15 minutes and plug one thing at a time my system will run for a little while but will drop wan connectivity to my internal network. I am thoroughly convinced that Asus router will not work with charter surfboard modem. it must have something to do with locality since there are others who say they have no issues.

 

[JS_racer]

N66 with a sb6120 working great with charter. Current firmware is Merlin 3.0.0.4.374.38. 2-em

It does work, never a problem here. Not sure why it does or doesn't.

 

[micksh]

Hi! I'm glad I found this forum. Thank you guys, especially Merlin.

Situation: router: AC66U (Firmware 3.0.0.4.374_726), ISP: Comcast, modem: Motorola SB6141
Everything has been working perfectly for 3 months. Yesterday I lost internet through router.

I had internet access when I connected laptop directly to modem, but router could not see it. Tried lots of things - powering off, resetting, different cables, etc. Nothing worked.
In router system log there were many entries "could not get IP address", several times per minute.

After I read this thread what fixed my internet was the following:
- Clearing MAC Address (router had old cloned MAC)
- Setting DHCP query frequency to Normal
- Powering down both router and modem for 15 minutes (rebooting didn't help)
After that everything has been working fine (did this few hours ago).

So, my guess is that Comcast also suddenly started to ban for frequent DHCP queries?
2Merlin: If so, maybe it makes sense to make Normal DHCP frequency default? And, perhaps, introduce more flexible frequency settings? Who knows what ISPs will consider too frequent requests in future.

Thanks again

 

[iaintnothug]

Thanks everyone!

I too noticed this with my ASUS RT-AC66U and Charter. They came in with a new modem and we're "testing" that but it seemed like after rebooting the router it has trouble reestablishing a connection even though I am connected to the web interface telling it to constantly detect a WAN connection.

I tried changing the DHCP query frequency from Aggressive to Normal and seemed to establish the connection again. I will try this for a few weeks and see how it goes.

Is anyone experiencing this issue with the new ASUS RT-AC68U? I'm just curious.

Thanks everyone!

 

[Marinemaster]

Merlin replied to one of my post that latest Asus fw 4422 had changed the timing for Charter so that should fix this issue.
Same thing happened to me last year sb6121 and rtn66 constant disconnect. Since then I got an Apple airport extreme 5th gen and has been perfect, never disconnected, never dropped the wireless. I had interference at some point but not router fault.
Charter did send me a new modem but is still in the box did not try it. I will at some point give rtn66 another try since price is lower and hopefully isp disconnect would be fixed.

 

[confubitated]

I just recently purchased the RT-N56U to replace my TrendNet N300 router running DD-WRT. I did this so I could place all my media streaming devices on the 5GHz band and the rest on 2.4GHz to hopefully get better performance.

I believe I have been having this exact same issue. For the past week since I've set everything up, I've ran the latest firmware from Asus, as well as Padavan's firmware. I experienced the issue on both firmwares, and it is usually just the inability to access the internet from the router. The modem is connecting fine (verified from calling Charter), and a reset usually fixes it briefly. After a while, I will eventually always lose internet connection and have to reset both.

I've switched the DHCP mode from aggressive to normal, and will monitor that. I did notice yesterday that my 30MB connection was going extremely slow, and in the past with my old router I never really had any slowdown. Overall, this router has been a giant pain in the butt for the first week. I know it can be great, but being that I am forced to use Charter as my ISP, I need to resolve this conflict or move onto a different router. I really hope this gets solved soon.

Are you guys actually resolving the issue by switching the DHCP mode from aggressive?

I noticed in my logs that the time synching seems to be strange (Jan 01). Does the issue stem from this?

 

[Poseidon]

Is anyone experiencing this issue with the new ASUS RT-AC68U? I'm just curious.

I haven't had a single disconnect with the RT-AC68U + Charter HSI + SB6141.

Previously with the N66U and the AC66U I would encounter multiple disconnects per week. Tried both Factory + Merlin firmware and nothing worked. I left Asus but decided to give them another try with the release of the AC68U and so far, so good.

 

[confubitated]

Bumping

I wanted to bring this thread back up to see if people have had any success.

I returned my Surfboard 6121 to Charter and now have a Cisco DPC3008 modem. In this process, Charter somehow got the MAC address of my two modems screwed up and I was without internet for a few days. A technician is coming out today to hopefully get that squared away. I am curious if my RTN56U with the latest official firmware set to "Normal" will work with a new modem.

Are you guys still dealing with this issue, and if so, what resolved it?

 

[zzyzx]

I wanted to bring this thread back up to see if people have had any success.

I returned my Surfboard 6121 to Charter and now have a Cisco DPC3008 modem. In this process, Charter somehow got the MAC address of my two modems screwed up and I was without internet for a few days. A technician is coming out today to hopefully get that squared away. I am curious if my RTN56U with the latest official firmware set to "Normal" will work with a new modem.

Are you guys still dealing with this issue, and if so, what resolved it?

I'm re-resurrecting this thread since I didn't see any other recent discussions on this. I've had continual problems with my N66u and SB6120 disconnecting. Most of the time the connection is quickly reestablished, but maybe once a month, it goes down and the only fix is to power cycle the modem and router.

Most recently, I've had a multiple day issue. Connecting directly to the modem, Internet is fine, but running through the router results in no connectivity. Seems to be a DHCP issue, but can't say for sure.

Anyone still having issues, or more importantly, anyone find a way to get more stability?

 

[confubitated]

I never had any luck with it. I somehow managed to brick the router as well, flashing firmwares. I now have an $80 paper weight...so I've just given up on it. Good luck to you man...

 

[zzyzx]

Fixed the issue today. I tried multiple times power cycling both the router and the modem with several minutes of downtime without success.

I tried one last time and changed the WAN DCHP settings. Under "Special Requirement from ISP" I changed MAC Address to <blank> and DCHP query frequency from Aggressive to Normal.

That seems to have done the trick, allowing me to write this post. I'll check back if something reverts down the road, but I'm hopeful the problem is solved.

 

[RMarkwald]

Hello everyone! First post, but I joined to chime in on this, as I am currently going through this myself at my duplex, RT-N66R with a Charter Surfboard modem. I've flashed and set up from scratch Merlin's latest.

I do have an IP in the DMZ.

I have set the WAN - DHCP to Normal.

During the day, it happens constantly, of course when I'm not at home. I get the "ISP's DHCP did not function properly" message in the system log, so I go through the process of waiting 10 minutes with everything unplugged from power, powering back up, and waiting...eventually I get the WAN back online.

I am going to try the MAC Cloning suggestion, as there was a MAC listed there. I am also going to try the forwarding of ports 67 and 68 to the router's IP based off of a suggestion on this site as well, due to having one IP in the DMZ possibly messing with things. I was trying to think back if this happened when I first turned on DMZ, but I do not recall.

Charter is sending me a new modem, as ever since they upgraded our modem so that we could receive their new Internet speeds, we've been having this issue, both with a Netgear router, and now this Asus. Hopefully, doing these steps + replacement modem = Internet at home that can stay up for more than 24 hours.

The tech did note that there were connection errors that the modem logged, so something on their end (modem, connection at the box, cabling, etc) could be an issue, so if this continues, a tech will have to stop out and troubleshoot.

I'll report back with my findings over the next few days here.

 

[RMarkwald]

Well it has been almost three weeks now since I posted, and ever since I got rid of the Motorola SurfBoard cable modem and got the new Arris modem (can't recall the model # at the moment), I have not once had this issue. Charter did have a nationwide outage about a week and a half ago, but other than that, no errors in regards to the ISP's DHCP not functioning properly.