From 7759238f9108c86e9938661a3ac6ade01f653840 Mon Sep 17 00:00:00 2001
From: Jon Sands <fohdeesha@gmail.com>
Date: Wed, 16 Oct 2019 03:00:19 -0400
Subject: [PATCH] add 64nix docu

---
 documentation/64nix.md | 87 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 documentation/64nix.md

diff --git a/documentation/64nix.md b/documentation/64nix.md
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+# Assigning tons of /64s to *nix machines (telehouse-NY)
+
+### Get a /125 transit net for the connection to the server:
+`2620:57:e000:e::10/125`
+
+### give the first IP in transit subnet to the ICX7750:
+```
+enable
+conf t
+int ve 2000
+ipv6 addr 2620:57:e000:e::11/125
+ipv6 nd suppress-ra
+```
+The next IP after this, `2620:57:e000:e::12`, will be given to the server.
+
+### Choose a /56 to give to the server:
+`2620:57:e000:400::/56`
+
+### Tell the ICX7750 the entire /56 is accessible over previous transit link:
+```
+enable
+conf t
+ipv6 route 2620:57:e000:400::/56 2620:57:e000:e::12
+```  
+
+The destination is your chosen `2620:57:e000:400::/56` subnet, the next-hop is the server end of the transit subnet, `2620:57:e000:e::12`
+
+### On server, give it it's own address in the transit subnet:
+**Note**: this should be one address up from what the router (ICX7750) has.
+
+```
+nano /etc/network/interfaces
+
+auto eth1
+iface eth1 inet6 static
+        address 2620:57:e000:e::12
+        netmask 125
+        gateway 2620:57:e000:e::11
+        autoconf 0
+```
+Now run the below command to assign the entire /56 to the server's loopback interface:
+**Note:** this uses Linux's [AnyIP](https://blog.widodh.nl/2016/04/anyip-bind-a-whole-subnet-to-your-linux-machine/) feature.
+
+`ip -6 route add local 2620:57:e000:400::/56 dev lo`
+
+Your server will now respond to any address in the entire /56 - however most applications and daemons will complain when you try to bind them to an address in this block, since they're not *technically* assigned to any real linux interface. To solve this, enable the `net.ipv6.ip_nonlocal_bind` sysctl:  
+
+`sysctl -w net.ipv6.ip_nonlocal_bind=1`
+
+Applications can now bind to any IP address in the /56. To make this permanent so it persists reboots, you need to edit `/etc/sysctl.conf`:
+
+```nano /etc/sysctl.conf```
+
+Add the following line and then save it:
+
+`net.ipv6.ip_nonlocal_bind = 1`  
+
+The `ip -6 route` command we ran earlier to assign the /56 will also disappear on reboot, to make it persist reboots, add it as a `pre-up` command to our network interfaces file, under your transit subnet interface:
+
+```
+nano /etc/network/interfaces
+
+auto eth1
+iface eth1 inet6 static
+        address 2620:57:e000:e::12
+        netmask 125
+        gateway 2620:57:e000:e::11
+        autoconf 0
+        pre-up ip -6 route add local 2620:57:e000:400::/56 dev lo
+```
+
+### Finding all the /64s to bind to
+If your application needs to be bound to each /64, stick our `2620:57:e000:400::/56` subnet into [this calculator](https://subnettingpractice.com/ipv6_subnetting.html), and choose /64s from the dropdown then press calculate:
+
+![eeprom](../../data/other/64nix-1.png) 
+
+Then simply bind each of your application instances to the first address in each /64 - For instance:
+
+```
+Instance 1 - 2620:57:e000:400::1/64
+Instance 2 - 2620:57:e000:401::2/64
+Instance 3 - 2620:57:e000:402::/64
+etc etc etc
+```
+
+
+