Joined: 01 Dec 2021 Posts: 289 Location: Maryland, United States
Posted: Mon Dec 27, 2021 3:35 Post subject:
No success with the /56 prefix. If I connect the computer directly to the modem the computer has IPv6. With Windows 10 I can look at the Network and Internet setting which shows an IPv6 prefix of /64.
I think the first issue to figure out is having the router pick up an ipv6 address itself (ie act as a client)... getting it to act as a router for ipv6 is a different problem...
Comcast's documentation is rubbish on ipv6 and I cannot find anything useful to help on settings... Do you think if you called customer/tech support they would give you the settings for ipv6 (ie whether to use dhcpv6 or slaac, what delegated prefix)
Out of stupidity sake... did you connect this router with stock firmware and get an ipv6 address?
vCMTS vs CMTS should be completely transparent to the user... they are just virtually emulating the CMTS system as opposed to having physical hardware... this is independent of the ip layer (and as long as your modem is doing the physical translations properly...)
Let me play with some things and do some more research a little later today and I will come back and give some ideas/options
Posted: Mon Dec 27, 2021 19:45 Post subject: comcast pd ipv6
I have spectrum and it does /56. It also does /60 which I use for the wan for now instead of a /56. I use an openwrt router for this. The modem is on bridge mode. I have a merlin router attached to the openwrt router. The openwrt router has 4 vlans with one being a /62 feeding the merlin one. The merlin router has no problem carving up the /62 it receives from the openwrt router into a /64. On the other 3 vlans I have /64. This feeds the computer I'm on now. Another is for streaming. The merlin router is a vpn router for guests. I don't know how to setup DD-WRT to receive a/56 or /60 and then have the ipv6 carved out to a /64.
and they are pretty crap... I found others, but there are so many inconsistencies... and each one has a different setting...
So my best suggestion is to call customer support and ask them what the settings that they recommend for ipv6 to a router... from there we can help translate to what it should be set on dd-wrt... it is entirely possible that comcast has messed something up ... but I am still leaning towards we are talking past each other.
Joined: 01 Dec 2021 Posts: 289 Location: Maryland, United States
Posted: Mon Dec 27, 2021 23:55 Post subject:
Wildlion wrote:
Out of stupidity sake... did you connect this router with stock firmware and get an ipv6 address?
The Netgear router with the stock firmware connected to the Arris SB8200 modem gives me IPv6 with a WAN address with a 64 prefix and also sets up the LAN with a 64 prefix. So I can get IPv6 on my computer. Unfortunately, the techs at Comcast really don't know much about IPv6 they only know and can test if I get internet. They know a bit more about the router they lease and have diagnostic software that they can use to verify if their leased routers are working correctly.
Before I switched to dd-wrt on the Netgear R6300 I had problems for several months losing IPv6 after an hour or two (with the two hour lease time). I then found out they implemented vCMTS at that time. About two weeks ago they did something to vCMTS and increased the lease time to four days. I then tried the stock Netgear firmware again and it stayed connected to IPv6. This change did not help dd-wrt recognize IPv6.
Joined: 01 Dec 2021 Posts: 289 Location: Maryland, United States
Posted: Tue Dec 28, 2021 4:33 Post subject:
All I did using the Netgear firmware was enable IPv6 and then use Auto Detect. It would then connect me using DHCP. As an alternative as long as IPv6 was enabled if I rebooted the router it would connect me using DHCP. Their were no setting that I had to put in.
I was thinking about a hardware or software problem on Comcast part except that directly connecting my computer to the modem connects IPv6 and now with the original Netgear firmware the router also picks up IPv6. So I assume their is something in vCMTS that make IPv6 from the WAN slightly different that dd-wrt does not recognize. Something also I need to mention on extremely rare occasions using dd-wrt after a reboot dd-wrt obtains an IPv6 WAN address after a reboot (but it does not transmit the IPv6 to my computer) I can have the same settings and reboot the router multiple times and no IPv6. I once tried rebooting the router 10 times in a row after getting IPv6 but no IPv6. So very rarely dd-wrt recognizes IPv6 from the modem.
Joined: 01 Dec 2021 Posts: 289 Location: Maryland, United States
Posted: Sun Jan 02, 2022 0:06 Post subject:
kernel-panic69 wrote:
Well, there are only two things at play here : Comcast's IPv6 / vCTMS situation and (likely) what dhcp6 / IPv6 implementations are in the stock firmware or DD-WRT. Configuration issue or Comcast is b0rked. This is why I think that reserving all the code blocks when TCP/IP went public was a bad idea. Because now we have to deal with the haphazardly implemented IPv6 and CGNAT.
We literally cannot use the ISC dhcp client and server, etc. in embedded linux IRT custom firmware due to code size; I don't know exactly what the stock firmware is using, but I do recall seeing it in Linksys E-series device code tarballs in the past.
I certainly wish I could be of assistance. Searching the DD-WRT forums for the term IPv6 I found a least a handful of posters using Comcast that are having problems getting IPv6 to work. As I stated in my previous post with the implementation of a four day lease (still using vCMTS) I again tried the stock Netgear firmware which is several years old and had no problems connecting to IPv6 getting both a WAN and LAN address and IPv6 was recognized by my Windows 10 computer from the R6300 router.
I find DD-WRT to be a great alternative to the stock firmware with so many additional options (that I wish I could understand!) and from a security prospective essential after a manufacturer discontinues support.
Joined: 13 Aug 2013 Posts: 6872 Location: Romerike, Norway
Posted: Sun Jan 02, 2022 10:26 Post subject:
There is a debug in radvd, so you can inspect the announcements coming in.
-d debuglevel, --debug debuglevel
With this option you turn on debugging information. The debugging level is an integer in the range from 1 to 5, from quiet to very verbose. A debugging level of 0 completely turns off debugging. If a debugging level greater than 0 is used, radvd doesn't background itself on start. The default debugging level is 0.
Joined: 01 Dec 2021 Posts: 289 Location: Maryland, United States
Posted: Sun Jan 02, 2022 17:12 Post subject:
Since I am a novice and do not know Linux I tried putting "radvd -d 1" in the command line. What happened after I applied the command is I still had an internet connection but could no longer access http://192.168.1.1/. Thank you for your assistance!
Update: I am not sure but I may be having problems with my router or possibly the latest beta firmware. I reset the router three time using the 30-30-30 reset but now when I do the apply command even when not changing anything it disconnects me from the router page but the internet still works. I cannot access the router page until I reboot the router. I will probably wait for another router firmware update before I try the apply command again.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Wed May 25, 2022 8:53 Post subject:
Note that when you click Apply Settings, many services are restarted, so loss of access to UI is expected and will be restored when services HAVE FULLY restarted.