README.md in infrataster-0.1.8 vs README.md in infrataster-0.1.9

@@ -61,19 +61,19 @@
 ```ruby
 # spec/spec_helper.rb
 require 'infrataster/rspec'
 
 Infrataster::Server.define(
-  :proxy,          # name
-  '192.168.33.10', # ip address
-  vagrant: true    # for vagrant VM
+  :proxy,           # name
+  '192.168.0.0/16', # ip address
+  vagrant: true     # for vagrant VM
 )
 Infrataster::Server.define(
-  :app,            # name
-  '172.16.33.11',  # ip address
-  vagrant: true,   # for vagrant VM
-  from: :proxy     # access to this machine via SSH port forwarding from proxy
+  :app,             # name
+  '172.16.0.0/16',  # ip address
+  vagrant: true,    # for vagrant VM
+  from: :proxy      # access to this machine via SSH port forwarding from proxy
 )
 
 # Code generated by `rspec --init` is following...
 ```
 
@@ -115,21 +115,21 @@
 ```ruby
 Infrataster::Server.define(
   # Name of the server, this will be used in the spec files.
   :proxy,
   # IP address of the server
-  '192.168.44.10',
+  '192.168.0.0/16',
   # If the server is provided by vagrant and this option is true,
   # SSH configuration to connect to this server is got from `vagrant ssh-config` command automatically.
   vagrant: true,
 )
 
 Infrataster::Server.define(
   # Name of the server, this will be used in the spec files.
   :app,
   # IP address of the server
-  '172.16.44.11',
+  '172.16.0.0/16',
   # If the server is provided by vagrant and this option is true,
   # SSH configuration to connect to this server is got from `vagrant ssh-config` command automatically.
   vagrant: true,
   # Which gateway is used to connect to this server by SSH port forwarding?
   from: :proxy,
@@ -143,9 +143,30 @@
 ```ruby
 Infrataster::Server.define(
   # ...
   ssh: {host: 'hostname', user: 'testuser', keys: ['/path/to/id_rsa']}
 )
+```
+
+### fuzzy IP address
+
+Infrataster has "fuzzy IP address" feature. You can pass IP address which has netmask (= CIDR) to `Infrataster::Server#define`. This needs `vagrant` option or `ssh` option which has `host_name` because this fetches all IP address via SSH and find the matching one.
+
+```ruby
+Infrataster::Server.define(
+  :app,
+  # find IP address matching 172.16.0.0 ~ 172.16.255.255
+  '172.16.0.0/16',
+```
+
+Of course, you can set fully-specified IP address too.
+
+```ruby
+Infrataster::Server.define(
+  :app,
+  '172.16.11.22',
+  # or
+  '172.16.11.22/32',
 ```
 
 ### #ssh_exec
 
 You can execute a command on the server like the following: