Static IPv6 on Comcast network.

[thetibetantr]

I am having trouble stetting up a static IPb6 on Comcast.  I have a business account and they told me I was assigned 2603:XXX:YYY:ZZZ::/56.  Everything I have read online says that I should set the WAN interface to DHCPv6 and the prefix delegation size to "56".   When I do that I see the following on the Comcast modem:

Internet: Active
WAN IP Address (IPv6): 2001:558:6031:70:a59d:4c3:f6fc:ce79
WAN Default Gateway Address (IPv6): fe80::201:5cff:fea9:5246
Delegated prefix (IPv6): 2601:980:c300:4f0::/64
WAN Link Local Address (IPv6): fe80::fad2:acff:fe94:16a
DHCP Client (IPv6): Enabled


And the WAN interface shows:

# ifconfig em0
em0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: WAN (wan)
options=4802028<VLAN_MTU,JUMBO_MTU,WOL_MAGIC,HWSTATS,MEXTPG>
ether 52:54:00:23:cf:af
inet 50.76.207.253 netmask 0xfffffff8 broadcast 50.76.207.255
inet6 fe80::5054:ff:fe23:cfaf%em0 prefixlen 64 scopeid 0x1
inet6 2601:980:c300:4f0:5054:ff:fe23:cfaf prefixlen 64 autoconf pltime 300 vltime 300
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>


I have also set a VLAN interface's "IPV6 configuration Type" to "tracking". 

The VLAN only shows a link-local IPv6 address.

Is there a HOW-TO for configuring an static IPv6 that doesn't use DHCP to get the address?

[Budroid]

I found this guide and am hoping to try it out myself within a week or so. I'll post back with my results.

https://homenetworkguy.com/how-to/configure-ipv6-opnsense-with-isp-such-as-comcast-xfinity/

[OPNenthu]

I have their residential service which is limited to /60 but otherwise working fine with DHCPv6 on WAN.  The instructions from @meyergu in this post do work with Comcast and should get you up and running with SLAAC on the LAN side, if that's all you need.

Delegated prefix (IPv6): 2601:980:c300:4f0::/64

This seems off to me-

If the ISP promised you a /56 then I would expect that to be reflected in the Delegated prefix.  Here you are showing a /64 which means you can't create any subnets in OPNsense.

I wonder if the modem configuration needs to be updated.  Have you received any updates or rebooted since?

[Budroid]

So far I have had mixed results.  We have Comcast business and a /56 static IPV6 allocation. The network here is somewhat complex in that there are multiple LANs and multiple VLANs on the inside.  I was able to get one VLAN to work with IPV6 using Track Interface. When I configured a second VLAN interface with Track Interface and a prefix it started working with IPV6 as well but that broke the first VLAN - it quit working until I removed IPV6 config from the second VLAN. I haven't yet tried SLAAC.

I haven't had time to go through the logs and work on this without causing a network to be down and impact others.  I hope to try to get more info this week.

[Budroid]

Well, I tried OPNenthu's Link and I have 3 of my internal networks functional with IPV6 on Comcast. I still have more to configure but this is the most functional that I've ever had IPV6 on our networks.

[OPNenthu]

Well, I tried OPNenthu's Link and I have 3 of my internal networks functional with IPV6 on Comcast. I still have more to configure but this is the most functional that I've ever had IPV6 on our networks.

No credit to me.  That is @meyergru's write-up. :)  Glad it's working.