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Arris SB6190 cable modem strange issue with DHCP

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Arris SB6190 cable modem strange issue with DHCP

I currently have a Motorola/Arris SB6141 cable modem. It is conected to my TP-Link WiFi router and works flawlessly.

 

I wanted to upgrade my cable modem, as I have received calls from Comcast indicating my current modem may not be able to keep up with the speed of my Blast Internet service. So I purchased the Arris SB6190 as a replacement. I was able to have Comcast successfully provision the modem and by using speedtest saw a 50 MBps increase in  my throughput.

 

However, I now have new interesting issue that I cannot find an answer to. When only my router loses power or reboots it does not get an WAN ip address back via the cable modem. This works just fine on the old SB6141 model but not on the new SB6190 model. The only way I can get the router to get the WAN IP address back after losing power to the router is for me to reboot the cable modem. Then all is well again. This is a problem in that I have to intervene after a power outage of the router, as then I have to manualy reboot the cable modem once the router is up.  Interestingly, I can from the TP Link GUI do a DHCP release/Renew on the WAN IP address and that works just fine getting the IP back. 

 

The only advice Arris has given is that maybe the comcast firmware is corrupted. I am running firmware 9.1.103AA40  and as I said, other than this problem all is working well.  I've had comcast reprovision the modem twice with the same results. I am going to try a hard reset of the cable modem in order to force the firmware download again as suggested by Arris. Is it possible the provisioning of the modem is the problem or that the firmware has a bug and is what is at fault here? Thanks in advance for your help.

 

 

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Expert

Re: Arris SB6190 cable modem strange issue with DHCP

Have you tried depressing and holding in the recessed reset button on the rear for 30 seconds ? This will help pull a new copy of the firmware load.



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Re: Arris SB6190 cable modem strange issue with DHCP

I have tried holding the hardware reset button until I see the modem lights go out and it resets (about 10 secs). I'm told however, I should not have the cable coax connection attached while doing so. So I want to repeat this w/o the coax attached and then let it fully boot before reattaching the coax cable.

 

Also the current firmware version is: v9.1.103AA40 on my cable modem for the Arris SB6190 

Does anyone know if this is the latest available version that Comcast is using?

Expert

Re: Arris SB6190 cable modem strange issue with DHCP

That's the latest one AFAIK.
If losing power is an issue, why not invest in an inexpensive UPS to keep your electronics continuously powered but also avoid damaging surges and spikes? You can get one for under $25:

https://www.amazon.com/dp/B00NTQYUA8/ref=cm_sw_r_cp_api_eIYFBb6GRRRAF

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Re: Arris SB6190 cable modem strange issue with DHCP

Thanks for the suggestion of a UPS.

 

I tried the hard reset using the push button on the back of the SB6190 this evening. It did not change anything. I think this is just how this modem is configured to work.  Maybe it is a bug in the latest firmware? I am back to using my SB6141 which works beautifully and will pass an IP address to my router just fine if my router power cycles. Not sure what else I can do at this point.

 

Just curious if anyone else has a SB6190 and can reboot/power cycle their router and it gets an IP addres back after it comes back online?? Or do they then always have to powercycle their modem as the final step in order to have their internet work?

 

If this is not a bug in the cable modem firmware,  then the only other possibly could be a configuration issue on Comcast's part. I spoke to Arris tech support and they say that since this device is just a bridge they do not block any dhcp broadcasts. So if the dhcp server at Comcast is not responding it must be a config issue.

Contributor

Re: Arris SB6190 cable modem strange issue with DHCP

I have the SB6190, and power cycling does not present the issue. I obtain an IP address without issue.  I power cycle monthly.  I do have mine on a UPS, as another suggested, as well as my router, to protect the equipment. We seem to take a  lot of power hits in my area..  

Frequent Visitor

Re: Arris SB6190 cable modem strange issue with DHCP

Thanks for the info.  Do you mind telling me what model router you are using with your cable modem? Do you happen to know the version of firmware running on your SB6190 cable modem?

Frequent Visitor

Re: Arris SB6190 cable modem strange issue with DHCP

 I'm unable to find an answer/solution to get the Arris SB6190 to pass the WAN IP address to my TP Link Archer C8 router after the router reboots/power cycles. I'm back to using my previous cable modem the Arris/Motorola SB6141. If anyone reads this, I still have the SB6190 and willing to try other tests.  I still feel this could be a configuration issue on Comcast's part and/or a modem firmware bug.

 

Just to reiterate my issue.... my router can reboot or power cycle at anytime and get an IP address from my current SB6141 cable modem just fine. But not using the new SB6190. The SB6190 MUST be rebooted after the router is already up for a WAN IP address to be sent to the router.

 

 

Contributor

Re: Arris SB6190 cable modem strange issue with DHCP

It is a tp-link archer c5400 v1. My cable modem is software version 9.1.103AA45. Have you called Comcast? Is it possible the reserved the IP to the old MAC address?
Expert

Re: Arris SB6190 cable modem strange issue with DHCP


@teddmf wrote:

 I'm unable to find an answer/solution to get the Arris SB6190 to pass the WAN IP address to my TP Link Archer C8 router after the router reboots/power cycles. I'm back to using my previous cable modem the Arris/Motorola SB6141. If anyone reads this, I still have the SB6190 and willing to try other tests.  I still feel this could be a configuration issue on Comcast's part and/or a modem firmware bug.

 

Just to reiterate my issue.... my router can reboot or power cycle at anytime and get an IP address from my current SB6141 cable modem just fine. But not using the new SB6190. The SB6190 MUST be rebooted after the router is already up for a WAN IP address to be sent to the router.

 

 


I admit it's rather strange. Typically, you'd have to reboot both the modem and the router only if you were using a new router, or new modem, or both.

You could try a complete wipe of the SB6190 by pressing the reset button in the back for 30 seconds while the modem is powered up and disconnected from the coax cable. 


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Re: Arris SB6190 cable modem strange issue with DHCP

I've tried holding the reset button on the modem for 30secs while its powered and disconnected from the coax. It made no difference.

Frequent Visitor

Re: Arris SB6190 cable modem strange issue with DHCP

Hmmm....your firmware is newer....mine ends in 40 ....yours 45.  I'm going to try the hard reset with the cable connected to see if it will get new firmware.

Frequent Visitor

Re: Arris SB6190 cable modem strange issue with DHCP

Tried the paper clip reset for 30 secs with and without coax attached. No change in firmware. I live in NH. Maybe version 40 is the best they have available on their server in this area?