Compatibility: Using Comcast firmware on RCN for C7000v2

[enn]

My ISP is RCN.  My current firmware is V1.02.14.  I see Comcast is using V1.03.01.  I was advised that if I wanted to, I could go to a neighbor's house who is using Comcast, hook up my modem/router and it will automatically update to V1.03.01.  I'm visiting family in a few days and their ISP is Comcast.  

First, is that accurate?  Can I just connect the cable at my relative's house to my modem/router and it will automatically update to the newer firmware?

Second, when I get back home, will the c7000v2 still work with my RCN service?

[FURRYe38]

Possible however you would need to reconnect your family members modem back to there ISP service afterwards. Not sure if the ISP would allow this. 

Even if you got FW on the modem from CC then reconnected it back to RCN, RCN may re-load there FW on the modem after it's connected. 

[plemans]

I wouldn't do it. I've see issues where modems have been provisioned for 1 isp's service and gets locked to that provider or stuck provisioned at IPv4 when the other provider needs IPv6 to provision. Not saying that'll happen here but its always a possiblity. 

Plus even if it upgrades, when RCN re-provisions it, it'll be provisioned with their approved firmware and be downgraded back to what they've approved. 

so its a bit futile. 

[enn]

Thanks for your responses.  I decided against trying to update the firmware.  But now I know why other advised not to get a modem/router combo.  I did not know that firmware updates could only be made by the ISP.