Learn me on some ipv6

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bds1904

Gawd
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Aug 10, 2011
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So the other day i noticed that my AT&T NVG589 was issuing me an ipv6 address in the range of 2602:306:3276:da20::/64.

The modem is showing the following

Link-local IPv6 Address fe80::42b7:f3ff:fee4:95c0
Router Advertisement Prefix 2602:306:3276:da20::/64
IPV6 Delegated LAN Prefix 2602:306:3276:da20:: & 2602:306:3276:da28::

Can someone please explain what these mean.

Also, when i go to http://ipv6-test.com/ it shows that my address is "global unicast / native ipv6". Does that mean it's not running in a 6to4 tunnel?
 
There's more to know than what you're asking, but what you're asking are great questions and definitely a great basic understanding.

Basically, your link local address is inherent to your device, your modem router. It is an address that connects directly to the router it is connected to ( your isp's gear). The ISP router would have a link local address too. The two are literally the local addresses that "talk" to each other.

The router advertisement basically gives you your default route and where to find a DHCP server to get a wan address and delegated prefix.

The delegated prefix is the network block of addresses you are assigned to use. In IPv6 a /64 is the minimum PD and is like 18 quintillion addresses, so enjoy!

This is an overly basic explanation and I welcome others to add/correct what I've written. While I've deployed IPv6 on a network, I'm self taught, know enough to be dangerous and haven't touched it in a few months. Disclaimer: I have a shitty memory.
 
bds1904 said:
Also, when i go to http://ipv6-test.com/ it shows that my address is "global unicast / native ipv6". Does that mean it's not running in a 6to4 tunnel?
Click to expand...


Yeah, it sounds like it if it's saying it's (your PC) has a Native IPv6 address globally unique and able to communicate with other IPv6 enabled machines. ISP's have been rolling it out silently for the past 2 years and most of there gear is starting to support a very similar set of IPv6 standards (about time). The problem partially with IPv6 which you'll find gear 6+ years older claiming "support" was that it was always partial or not agreed on by others. Then there was the physical problem of the hardware expense to replacing current gear.

Sounds like AT&T in your region is ahead of the curve and so is all your gear to fully support IPv6 as well as IPv4, which we'll probably have both running simultaneously for the next decade at least starting when IPv6 hits 50% penetration.

As far as the other details, Ehren8879 pretty much hit things on the head as best as I understand them. IPv6 still blows my mind, perhaps it's the hexidecimal that really scares me, but once you learn IPv4 (which can be hard at first) man it's cake compared to re-learning all of what IPv6 consists of, so I wont bother going into details more than Ehren8879 did because that's about what I know.
 
If I recall correctly the original idea with IPV6 was that NAT was unnecessary in this glorious future and every device would have a globally unique, bought and paid for IP address; but I think us peasants revolted against our corporate overlords and rejected this. I don't know if any sort of private IP range for IPV6 has been set though.
 
To elaborate on my previous post

Router Advertisement Prefix 2602:306:3276:da20::/64

This bit tells me that your internet provider is advertising a prefix via the router advertisement, which allows your modem/router to perform stateless auto configuration or SLAAC. I am unsure if your Prefix Delegation (LAN network :da28::/64) is also a stateless assignment or via DHCPv6-PD.

Some terms to research are Router Advertisement/solicitation, Neighbor advertisement/solicitation, SLAAC, DHCPv6, M&O bits (related to router advertisements) and prefix delegations.

IPv6 brings some new terms to the table, but it isn't really that difficult. I'd be happy to help anyone make sense of it, but I'm certainly no expert.


unholythree said:
If I recall correctly the original idea with IPV6 was that NAT was unnecessary in this glorious future and every device would have a globally unique, bought and paid for IP address; but I think us peasants revolted against our corporate overlords and rejected this. I don't know if any sort of private IP range for IPV6 has been set though.
Click to expand...

There things called Unique Local Addresses, but they are mainly used for non-internet facing devices. I don't know of any networks that employ NATv6 in production. Proper firewalling rather than NAT is the best practice security measure for IPv6.
 
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