NetLogo 7.0.0-beta2:

nw:generate-ring

nw:generate-ring turtle-breed link-breed num-nodes optional-command-block

Generates a ring network of num-nodes turtles, in which each turtle is connected to exactly two other turtles.

The number of nodes must be at least three.

If you specify an optional-command-block, it is executed for each turtle in the newly created network. For example:

Take me to the full Networks Extension Dictionary