10-69-net Network

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Last updated April 20, 2020 by Zach

The 10-69 network is a custom Link Local network used by NYC Mesh for connecting between nodes.

Each Node ( actually, each router at a node ) will have an address from the subnet 10.69.0.0/16, using the last two octets for node identification, described below.

The 10-69 network should not appear in routing tables around the network, only the individual IPs, which indicates they are online.

The network can also be used as a ways to predicatively get to a specific node by node-number: Simply connect to that node’s 10-69 IP address.

Node Identification

Each Node can auto-generate its own 10-69 net number by the following method:

For the subnet 10.69.X.Y/16, we need to determine X and Y. Note X and Y are both 0-255, as this is an IPv4 address.

For node numbers up to 5 digits long, segment the lowest two digits (one and tens places) and place them in Y. All other higher digits (hundreds, thousands, ten thousands) should be moved to X.
In other words, physically split the number into two segments.

For Example:

Node Number X Y 10-69-net Address
5 0 5 10.69.0.5
50 0 50 10.69.0.50
500 5 00 10.69.5.0
5000 50 00 10.69.50.0
50000 X Y Not Possible
25599 255 99 10.69.255.99

Note that the maximum node number via this method is 25599.

Second Routers

Each Router at a Node ( often one router ) will need a different 10-69 address. To make things easy, we have optimized for the common case of one router, above.
The second most common case, of two routers, is just as easy.

Simply add 100 to the Y value. All Y values between 100-199 are reserved for the Second router at a site.

For Example:

Node Number X Y First router Second Router
5 0 5 10.69.0.5 10.69.0.105
50 0 50 10.69.0.50 10.69.0.150
500 5 00 10.69.5.0 10.69.5.100
5000 50 00 10.69.50.0 10.69.50.100
50000 X Y Not Possible No Possible
25599 255 99 10.69.255.99 10.69.255.199