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I've been using Starlink since early 2021 with IPv6 only internally. Starlink User Terminal hands out a /56 prefix (via DHCPv6) and mine has not changed in all that time so I wouldn't call it dynamic.

The User Terminal issues a router advertisement (RA) and my gateway gives itself an address in that /64 via SLAAC in addition to assigning itself an address from the /56 prefix.

If not using prefix delegation each host's address is dependent on their SLAAC policy - if not preferring stable addresses (e.g: EUI64) then of course the public address will vary (be dynamic) when using temporary "privacy" addresses.

My gateway delegates /60 sub-prefixes of the /56 and bare-metal hosts then either delegates /62 or advertises /64s from the /60 to VMs, containers, network namespaces and so forth.

As someone else described, I have my gateway also delegate ULA prefixes by changing just the first two octets of the public delegated prefix to fddc (fd = ULA, dc = "data center :) but otherwise identical and likewise on the bare-metal hosts, etc.

ULA is used for internal services; ISP delegated prefix for anything that needs public access.

Multicast-DNS takes care of internal hostnames; everything is ${hostname}.local

There's a separate VLAN for legacy IPv4-only devices that does NAT64 using a ULA prefix.

DNS64/NAT64 for the laggards like github.com that can't grok 128 bit addresses :)

The only time I have problems with web services is when their DNS advertises an AAAA resource record but their firewall/load-balancers/servers are not configured to allow/listen on it.



Thanks for the report with success with IPv6 and Starlink. Do you make inbound connections to devices on your LAN? Do they work?

Starlink recently updated their FAQ with more info on addressing: https://www.starlink.com/support/article/1192f3ef-2a17-31d9-...

As for static addresses, it says "a reservation system retains the ... IPv6 prefix even when the system is off or rebooted. However, relocating the Starlink or software updates may change these addresses."

I suspect in practice the IPv6 address will only change if you get moved to a different POP ground station. Some customers never get moved. I've been moved several times because I'm in NorCal and they keep switching me between Seattle and Los Angeles.

Here's some recent discussion of users reporting what they've observed about changing IPv6 addresses: https://www.reddit.com/r/Starlink/comments/1b6mr4c/how_stati...


Yes, I use direct IPv6 peer-to-peer connections both outbound and inbound using the delegated prefix.

Even for a changing prefix, if operating a DNS authoritative server for a domain, any changes to the prefix can be quickly and automatically updated in both forward (AAAA) and reverse (PTR) resource records provided the TTL for those records is appropriately short, and thus allow almost seamless inbound via FQDNs. I do this with a bind9 (hidden) master locally that notifies external slave servers operated by a highly available, anycast, DNS service.


> Starlink User Terminal hands out a /56 prefix (via DHCPv6) and mine has not changed in all that time so I wouldn't call it dynamic.

Unless the service explicitly states that your subnet is your or yours alone you should assume it's dynamic.

If you start relying on the prefix not ever changing you might have a bad surprise.

And from experience, that kind of surprises always come when you least need them.




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