[Discuss] Very odd RCN behavior, PC can connect, but not routers

[j.natowitz at rcn.com (Jerry Natowitz)]

Every few years RCN seems to throw me a curve ball. Several years ago it was the mysterious bad provisioning that would keep getting applied to my modems. Now, I have a new puzzler. As of this morning, the Arris cable modem I rent from them refused to give my two month old Netgear R6300V2 a DHCP address on the WAN side. Went through the usual, disconnect, power down, power up in sequence. No luck. Switched the router with my old TP-LINK WR1043ND. Same behavior. Connect the PC directly to their modem and voila! DHCP worked. 

So they say there is no problem with their equipment. 

I don't have an easy way to capture traffic between the routers and the modem and compare it to the traffic between the PC and the modem. I've tried using IP unicast rather than multicast (on option on one of the routers) no luck. 

I tried having a router use the same MAC as the PC (with the PC's interface offline), no luck. 

Any suggestions? 

Jerr Natowitz