I have a dhcp-related problem in my cable network. When all cable modems are being reset at once and try to get an IP, things get stuck. I see DHCPDISCOVER message from cable modems and DHCPOFFER sent back to them. Now a cable modem should send DHCPREQUEST, but instead it hangs out there quiet and in a while repeats its DHCPDISCOVER message. A Cisco CMTS is a dhcp relay.
When I reset cable modems one by one all goes smooth (DISCOVER, OFFER, REQUEST and ACK).
So I'm thinking that the bottleneck is a cisco router.
If anyone has experienced anything like that, please let me know. Thanks in advance.