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showergel
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Teacher

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15 Messages

Thu, Apr 16, 2020 10:20 PM

IPv6 Prefix Delegation to 3rd Party Router, Not Working (2020 Edition)

Hello!

I've posted about this before; ultimately there was no solution in 2019, so trying again in 2020. The goal is to use a 3rd party router behind the ATT modem in DMZPlus mode, exactly as prescribed by ATT. This means no switch swapping, no certificate hacking, no eapol fowarding.

What currently happens on a Pace 5268AC, firmware 11.5.1.532678-att, with a cradlepoint 4g router (I used to use pfsense) set as follows:

Firewall: Disabled

Address assignment: Public

WAN IP Mapping: Router WAN IP Address

Cascaded Router: No

SLAAC IPv6 Address: (whatever it is currently assigned)

Address from IPv6 Pool: something:fd10::something

Assign Fixed IPv6 Address: None

Prefix from DHCP6 Pool: something:fd18::/64

IPv6 delegation something::fd10::/60

When I observe the WAN interface on the Cradlepoint I see what I expect from IPv4. IPv6 is set on the WAN interface, but did not send a prefix delegation for the CradlePoint's DHCP6 server:

IPv6 Address something:fd10::763 /128

IPv6 DNS something:fd10::1

State : connected

Manufacturer : Cradlepoint

IP Address : att public ipv4 address

Netmask : 255.255.252.0

Gateway : att public ipv4 address

DNS Servers : att modem private ipv4 address

The Cradlepoint log is pretty clear with what the ATT Modem offered:

Thu Apr 16th 15:26:11 2020 WAN:IPPT.Auto6 INFO ip6info={

'ip_addresses': [('something:fd10:something', 64)],

'routes': [('something:fd10::', 60, 'fe80::something', '512'), ('::', 0, 'fe80::something', '1024'), ('something:fd10::', 64, '', '256')],

'dns': ['something:fd10::1'],

'pd_prefixes': [],

'pd_excluded': [],

'ip_address': 'something:fd10:something',

'prefixlen': 64,

'gateway': 'fe80::something',

'delegated_prefixes': [],

'reserved_addresses': ['something:fd10:something'],

'dnslist': ['something:fd10::1']}

Noting that the Cradlepoint is not being delegated a /64 prefix, which is what the cradlepoint is requesting in its DHCPv6. It should be getting the ::fd18::/64 prefix from the Pace router, but it is not providing the PD.

ATTHelp

Community Support

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191.9K Messages

Il y a 2 y

We are here to help, @showergel.

 

We recommend that you use DMZ plus to bridge your third party gateway to your AT&T gateway.

 

If you have any other questions about this, you can contact our paid service Connectech.

 

Let us know if this helps.

 

Marc, AT&T Community Specialist

Contributor

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3 Messages

Il y a 9 m

Found this thread searching to do the same on my pfsense box.  Eventually found this link, and just like you said, it has to be configured manually in config files for each LAN-side interface to ask for a /64.  Not sure if the same can be done on your cradlepoint.

https://github.com/lilchancep/att-pfsense-ipv6

I also have the latest RG, which is a Nokia BGW320-505.  I'm hitting full speed (500 symmetric, 600+ on speed tests and steam dl et al) with the BGW only plugged into my pfsense box (3 interfaces) via IP-passthrough.

tinslwc

Teacher

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207 Messages

Il y a 9 m

That GitHub page was the evolution of the work that I helped him with on this forum.  Not really sure what happened, but I cannot find the original post with all the good details.

(edited)

tonydi

ACE - Guru

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4.9K Messages

Il y a 9 m

@tinslwc   It may be in there, look at the bottom of the post just before herozero's post and click the View other replies link.  You'll see that same link repeated over and over as you expand and hopefully your post is in there someplace.

tinslwc

Teacher

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207 Messages

Il y a 9 m

@tonydi Apparently I'm a DA. This is the thread we worked it out on. Just didn't see that it had been collapsed.

tonydi

ACE - Guru

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4.9K Messages

Il y a 9 m

I don't know what a "DA" is in this context.  The collapsed thread seems to be an anomaly and I'm trying to make sure it doesn't rear its ugly head again. ;-)

tinslwc

Teacher

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207 Messages

Il y a 9 m

@tonydi DA = donkey with a lack of intelligence.

tonydi

ACE - Guru

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4.9K Messages

Il y a 9 m

LOL.....I've seen your posts and I'm pretty sure you need to drop that description.

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