I'm having a strange issue with ip-helpers (well actually cable-helpers as this is a CMTS). I have two sets of cable-helpers on a bundle - 2 pointing Cable modems to 2 DHCP servers - and 2 pointing CPE devices to two other DHCP servers.
All 4 DHCP servers are located on the same subnet - and traffic is routed along the same path for all 4 servers.
What happens is that suddently I'm no longer getting DHCP responses back from the DHCP servers for the CPE devices, the CM's are still getting responses from their DHCP servers.
This would obvious be a problem with the DHCP servers serving IP adresses to the CPE devices... BUT.. the problem occures randomly on any of 80 CMTS's while all others continue to receive DHCP responses from the DHCP server just fine.
Or in other words.. all DHCP traffic between one CMTS's CPE devices and the DHCP servers for those devices are suddently interrupted..
I have no clue as to what is going on - and my TAC technician isn't making any progress on the issue either..
Any suggestions on what to look for would be greatly appreciated !