Tag Archives: IPv6

IPv6 – too many addresses?

Talking with people about IPv6, I regularly hear the complaint that IPv6 subnets have “too many addresses”. That it is “wasteful” to use /64 subnets, and that we should subnet down to “more realistic” subnet sizes. The complaint comes from … Continue reading

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Why “why” matters

A participant on the NANOG mailing list recently made the comment that “with a small amount of conceptual knowledge, the differences between IPv4 and IPv6 become very very small.” True! And perhaps an anecdote will illustrate why conceptual knowledge, not … Continue reading

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Subnet Router Anycast Addresses – what are they, how do they work?

Discussions on several mailing lists have shown that there is still a lot of misunderstanding”out there” about what subnet router anycast addresses are, and how they work. This article aims to help out, because the concept is actually pretty simple.

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DHCPv6 – is REBIND pointless?

As part of improving our course materials, I was refreshing my understanding of DHCPv6 a couple of days ago, and found myself thinking about the REBIND message. After close consideration of the relevant RFC (RFC 3315), and even posting a … Continue reading

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A MikroTik router and Internode’s IPv6

Here is how I got my MikroTik RB951-2n working with Internode’s native IPv6 service over ADSL. I did not nut all this out myself; there was googling involved, but nothing I found was complete and many articles assumed I knew … Continue reading

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IPv6 – get to the church on time!

In a mailing list I frequent, the conversation turned to tunnels as a means of getting IPv6 access. A personage of note who shall remain nameless here said: > IPv6-over-IPv4 tunnels are perhaps worse than not doing it at all. … Continue reading

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IPv6 source address selection – what, why, how?

IPv6 source address selection must be very irritated; destination address selection gets all the press coverage. This article will start to redress the balance, by talking about what IPv6 source address selection is, why it is needed, and how it … Continue reading

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Why Not NAT?

NAT came into existence because of IPv4 address scarcity. With IPv6, that reason disappears. So, if we no longer need to multiplex addresses, should we retain NAT?

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Migrating applications to IPv6

So you have an application. It was written (as far as you know) without IPv6 in mind, and now it has to work with IPv6. How hard is that going to be? Well, it depends on the application. Most of … Continue reading

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/etc/gai.conf – it ain’t what you think it is

If you read the doco (like “man gai.conf“) you would be forgiven for thinking that the contents of /etc/gai.conf controlled source and destination address selection in IPv6. You would be wrong.

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