Skip to content
T

New Contributor

 • 

5 Messages

Friday, May 3rd, 2024 11:05 PM

CGA4332 Static IPv6

All,

I'm adding yet another thread on this topic, trying to get official guidance from Comcast Business regarding supported configurations.

I have static v4 and v6 addresses, I have my network router set to use PD to get a /59 prefix from the Comcast supplied CGA4332 modem. My prefix changes whenever the Comcast modem reboots for maintenance and/or some combination of my prefix lease expiring. My network router (Unifi UDM Pro) doesn't allow me to specify a network prefix hint to supply, nor am I able to specify a PD ID in the Unifi Network interface. Like many others, if I specify a static address on my network's router, I'm able to send data outbound, but the Comcast modem doesn't have a route in its routing table for incoming traffic.

In the Comcast modem interface, I am able to specify static routes for IPv4 targets, but not for IPv6. It seems like a pretty obvious solution to allow specifying static v6 routes on the modem so users don't have to keep going through this annoyance. As long as my route fits inside my delegated prefix, the route wouldn't even need to be forwarded on to Comcast, it would simply happen at my local modem.

What solution is being worked on for those of us paying for static IPv6 addresses and not actually receiving static addressing? It seems like a pretty obvious issue in the design to allow us to pay for something that we can't possibly use.

Official Employee

 • 

14 Messages

3 months ago

thetommyc, thank you for reaching out today. Just to clarify, you want to set specific routes for IPv6 however this is currently not an option you are seeing available on your end, correct?

New Contributor

 • 

5 Messages

@Comcast_Marcus​ My ultimate goal is to be able to assign a static prefix to my internal network and not have it change randomly. Whether that's accomplished by assigning a static prefix to my internal network and a static route on the modem, by the modem listening for announcements, or any other method is fine by me. But my internal router apparently does not and probably will not support a PD ID, nor specifying the network portion of the prefix I want assigned.

Thanks for the reply.

Official Employee

 • 

14 Messages

thetommyc, No problem at all, you know I have seen something along the lines of the same issue you are referencing elsewhere in the forum. Have you had a chance to try this workaround?

New Contributor

 • 

5 Messages

My router doesn't allow me to set a DUID manually, so if it adds some amount of randomness to the DUID value, then all bets are off. Currently my router's public address is received via SLAAC, and then PD for a /59 for the internal networks. Is the official guidance to use DHCPv6 for my router's public IP? That may get a consistent address for the Comcast modem side of my router, but I don't think that answers the issue of receiving a consistent prefix for my internal network. Am I incorrect there? Will the Comcast modem issue the same prefix to my router if I use DHCPv6 for the outside interface?

Official Employee

 • 

16 Messages

With the internal network, @thetommyc, have you attempted to use a different type of router to see if that helps? 

 

New Contributor

 • 

5 Messages

I'm certain some routers allow PD ID values to be specified, but mine doesn't. So a simple work around to the fact that Comcast appears to require announcements to add routes to the Comcast modem dynamically, allowing static routes to be added to the v6 network would fix this for everyone. There's already a provision for v4, so I'm not sure why there isn't one exposed for v6.

New problem solver

 • 

38 Messages

16 days ago

I'd like to know this as well.  I don't understand the lack of feature parity between IPv4 and IPv6 on their CPE.

Honestly, skipping the whole DHCP-PD setup and just specifying next hop for subnets inside the static /56 (even if the webui only allowed /64s or something) would be so much easier.  

(edited)