From 36e36cc746fad60a601d31792a4438afe01d1046 Mon Sep 17 00:00:00 2001 From: Mark Wooding Date: Thu, 13 Dec 2012 10:02:28 +0000 Subject: [PATCH] local.m4: Add a prose commentary on address allocation. The IPv4 allocation is summarized in the DNS zone repository; the IPv6 allocation wasn't described anywhere at all. --- local.m4 | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) diff --git a/local.m4 b/local.m4 index 45e498b..23e6f6d 100644 --- a/local.m4 +++ b/local.m4 @@ -33,6 +33,83 @@ m4_divert(-1) ###-------------------------------------------------------------------------- ### Packet classification. +## IPv4 addressing. +## +## There are two small blocks of publicly routable IPv4 addresses, and a +## block of RFC1918 private-use addresses allocated from the Cambridge G-RIN. +## The former are as follows. +## +## 62.49.204.144/28 +## House border network (dmz). We have all of these, but .145 +## is reserved for the router. +## +## 212.13.18.64/28 +## Jump colocated network (jump). .65--68 are used by Jump +## network infrastructure; we get the rest. +## +## The latter is the block 172.29.196.0/22. Currently the low half is +## unallocated (and may be returned to the G-RIN); the remaining addresses +## are allocated as follows. +## +## 172.29.198.0/24 Untrusted networks. +## .0/25 house wireless net +## .128/28 iodine (IP-over-DNS) network +## +## 172.29.199.0/24 Trusted networks. +## .0/25 house wired network +## .128/27 mobile VPN hosts +## .160/28 reserved, except .160/30 allocated for ITS +## .176/28 internal colocated network +## .192/27 house safe network +## .224/27 anycast services + +## IPv6 addressing. +## +## There are five blocks of publicly routable IPv6 addresses, though some of +## them aren't very interesting. The ranges are as follows. +## +## 2001:470:1f08:1b98::/64 +## Hurricane Electric tunnel network: only :1 (HE) and :2 +## (radius) are used. +## +## 2001:470:1f09:1b98::/64 +## House border network (dmz). +## +## 2001:470:9740::/48 +## Main house range. See below for allocation policy. +## +## 2001:ba8:0:1d9::/64 +## Jump border network (jump): :1 is the router (supplied by +## Jump); other addresses are ours. +## +## 2001:ba8:1d9::/48 +## Main colocated range. See below for allocation policy. +## +## Addresses in the /64 networks are simply allocated in ascending order. +## The /48s are split into /64s by appending a 16-bit network number. The +## top nibble of the network number classifies the network, as follows. +## +## 8xxx Untrusted +## 6xxx Virtual +## 4xxx Safe +## 0xxx Unsafe, trusted +## +## These have been chosen so that network properties can be deduced by +## inspecting bits of the network number: +## +## Bit 15 If set, the network is untrusted; otherwise it is trusted. +## Bit 14 If set, the network is safe; otherwise it is unsafe. +## +## Finally, the low-order nibbles identify the site. +## +## 0 No specific site: mobile VPN endpoints or anycast addresses. +## 1 House. +## 2 Jump colocation. +## +## Usually site-0 networks are allocated from the Jump range to improve +## expected performance from/to external sites which don't engage in our +## dynamic routing protocols. + ## Define the available network classes. m4_divert(42)m4_dnl defnetclass untrusted untrusted trusted mcast -- 2.11.0