All,
Been running multiple searches to see if this is a known issue but didn’t find it - if I missed it my apologies.
Deployment highlevel: 20+ RB-750GL installs at a single MDU property with each Mikrotik router running ROSv6.7 receiving an IP from a Motorola Surfboard SB6141 cable modem. Very basic configuration on the routers - nothing really special. Using default DHCP Client settings on the WAN port (ether1-gateway) to pull a public DHCP IP from the cable modem. First router install goes smoothly and up and running. Second install - and the cable modem won’t give out an IP to the 750GL!? What happens is that if we add a second Mikrotik (any of the 20) to any of the other 19 cable modems, no DHCP IP given, but any single Mikrotik on any ONE cable modem on the property and it works!?!
Our suspicion is that there is some field (we suspect it is the Client-ID field) is not being properly populated by the Mikrotik with the router’s MAC address, and is using the same client-id field in the DHCP request message and thus the CMTS DHCP server refuses the request (as it should)… I’m sending a tech out to do Wireshark captures, but I just had to ask if anybody is aware of this issue in this scenario? Any fixes? v6.10 is a bust (random reboots, settings not taking, etc) and am going to try v5.26 next, but any insight from the community would be welcomed!
Note - I have another property very similar topology running v6.7 but there the cable operator gave me static public IPs and they are running just fine (further confirms it’s a DHCP issue on the Mikrotik). Note that on the other 19 cable modems if I plug a laptop directly into them I get a public IP via DHCP right away from the cable modem - no issues…
Cheers,
DHCP perplexed (and with an unhappy customer)