Comcast XFINITY → Comcast Biz modem

Did the username and password change for the SMC modem overnight? I noticed the proxy arp stopped, but now I can't login to my modem anymore.

»[Connectivity] Bug in May 2012 SMC D3G Software Update?

You have to call in to business support and have them reset the user/pass to default after the latest firmware rollback/upgrade

Well that is nice of them. Thanks for the update.

Tell me about it. I knew about needing to call in, so over the weekend, I did. The tier 1 tech could not get his tools to work in order to change the password so he bumped to tier 2. In the meantime, however, he told me to hit the reset button on the back of the unit. Guess what, it dumped my entire config, including my static IP's, which meant I had zero internet access.

Thankfully, tier 2 called me back within about 20 minutes of this happening. He rebuilt the config, changed the password, and had me completely back up in less than 15 minutes.

So if tier 1 tells you to try a reset, DON'T!!

I have heard that is the only way to fix this issue is to factory reset the modem because the Comcast geniuses decided to rollback firmware. With the rollback you have to hard reset it to get back into it.

If you don't, they may do it remotely anyway. That was what the tier 1 tech did for me after the firmware rollback, but that tier 1 tech also was able to rebuild the config and restore my static IP information without a call to a tier 2 tech. Of course I had to still redo all of my LAN and firewall configuration myself (A PITA since the SMC gateway provides no way for the user to save LAN/firewall config in an easily restorable way).

The firmware rollback requires the modem to be hard reset if you want access to it again.

If by "hard reset", you mean that the customer must push the button on the rear of the router, that is not necessarily so. Perhaps you had to do that, but it is not a universal requirement.

It may require a factory default reset (some however, have reported that for their modem/connection the tier 1 tech was able to simply recreate the cusadmin account with no need to do a reset and config rebuild).

However, even when a factory reset is required, that reset can either be done remotely (the Comcast tech has access to more commands than the customer), or by the customer holding in the pushbutton for the factory default reset.

All I was trying to get across is that if Tier 1 could not get the cusadmin recreated and sends it tier 2 but in the meantime , if tier 1 says to push the reset button on the back of the modem and you have static IP's, you WILL lose all internet access until tier 2 calls you back, rebuilds the config, and pushes it to your modem.

I was lucky that I got a call back within 15 -20 minutes. It could have taken a few hours.

Depends...

I went through this whole "ARP storm" as well, but last week (after reading a several-page post here about it) I simply power-cycled my SMC D3G (and after it restarted itself twice), the ARP packets on my LAN stopped, but I too could no longer log into the gateway. I decided to wait before I called to get that fixed as I was in the middle of a major project and couldn't afford to lose any time. The next day I checked (just because you never know with Comcast) and whadaya know - I could log in with the customary 'cusadmin' and 'highspeed' just as before. No reset, no reboot, no nothing on my end; I have no idea what Comcast did to make that happen.

I have decided that a "wait and see" attitude with Comcast is often best, saving me from tier 1 techs who often make things worse (even though they are trying to make things better). Of course your results may vary depending on your location and the wind direction that day...