nanog mailing list archives
Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI
From: Iljitsch van Beijnum <iljitsch () muada com>
Date: Sat, 27 Nov 2004 18:25:52 +0100
On 27-nov-04, at 17:43, Paul Vixie wrote:
those of us who prefer static assignment + dhcp6 over EUI64 find a /64 to be an obscene waste of address space on a per-lan (or per-vlan) basis, but sadly there are already some cool wireless gadgets whose idea of ipv6 doesnot include either static or dhcp6 addressing, so there's some tension.
my house has four vlans (core, family, guest colo, and wireless) -- so inthe cisco home networking model i'd need a /62 for fewer than 50 hosts?
While IPv6 is still IP, it's not just IPv4 with bigger addresses. We have 128 bits, so we should make good use of them. One way to do this is to make all subnets and 99% of end-user assignements the same size. Yes, this wastes bits, but the bits are there anyway so not wasting them really doesn't buy you anything at this point. The advantage of having a fixed /64 per subnet is that one size fits all: there is no need to worry about the subnet size when designing the network, whatever happens, all hosts that you'll ever want to put in this subnet will fit in it. Always having a /48 has a similar benefit: if you ever need to renumber, you only need to do a search and replace on the top 48 bits, the internal addressing structure can remain the same.
In a parallel universe IPv6 could have 64 bit addresses, saving 16 bytes of overhead per packet (so the additional overhead re IPv4 would only be 4 bytes rather than 20), but here in the universe we're all most familiar with, this ship has sailed a long time ago.
i life fred's reasoning. companies with size and qualifications likecisco's should qualify for an ASN and for PI space. all the world's nota home-DSL or home-cable or isp-colo network. routing shouldn't alwaysfollow addressing. we'll need to discover a workable equilibrium unless we want to encourage NAT in IPv6 the same way we (passively) encouraged itin IPv4.
All I hear is how this company or that enterprise "should qualify" for PI space. What I don't hear is what's going to happen when the routing tables grow too large, or how to prevent this. I think just about anyone "should qualify", but ONLY if there is some form of aggregation possible. PI in IPv6 without aggregation would be a bigger mistake than all other IPv6 mistakes so far.
Current thread:
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32), (continued)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Iljitsch van Beijnum (Nov 26)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Owen DeLong (Nov 26)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Iljitsch van Beijnum (Nov 25)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Owen DeLong (Nov 26)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Fred Baker (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Fred Baker (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Sean Donelan (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Pekka Savola (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI prefix [Re: who gets a /32) Scott W Brim (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Paul Vixie (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Iljitsch van Beijnum (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Owen DeLong (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Iljitsch van Beijnum (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Owen DeLong (Nov 28)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Paul Vixie (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Iljitsch van Beijnum (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI bmanning (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Iljitsch van Beijnum (Nov 29)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI bmanning (Nov 27)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Leo Bicknell (Nov 28)
- Re: BBC does IPv6 ;) (Was: large multi-site enterprises and PI Paul Vixie (Nov 28)