Internal IP addresses
You should never reference a node by IP address, as these are subject to change at any time. For your reference however, the following internal IPs are reserved.
172.16.0.21 dh1.i
172.16.0.22 dh2.i
172.16.0.23 dh3.i
172.16.0.24 dh4.i
172.16.0.25 dh5.i
172.16.0.26 dh6.i
172.16.0.27 dh7.i
...
172.16.0.40 dh20.i
172.16.0.41 lb1.i memcached1.i redis1.i redis21.i www.example.com
172.16.0.42 lb2.i memcached2.i redis2.i redis22.i www2.example.com
172.16.0.43 lb3.i memcached3.i redis3.i redis23.i www3.example.com
172.16.0.44 lb4.i memcached4.i redis4.i redis24.i www4.example.com
172.16.0.45 lb5.i memcached5.i redis5.i redis25.i www5.example.com
172.16.0.51 db1.i memcached11.i redis11.i redis31.i solr1.i sphinx1.i
172.16.0.52 db2.i memcached12.i redis12.i redis32.i solr2.i sphinx2.i
172.16.0.53 db3.i memcached13.i redis13.i redis33.i solr3.i sphinx3.i
172.16.0.54 db4.i memcached14.i redis14.i redis34.i solr4.i sphinx4.i
172.16.0.55 db5.i memcached15.i redis15.i redis35.i solr5.i sphinx5.i
172.16.0.61 acc1.i
172.16.0.62 acc2.i
172.16.0.63 acc3.i
172.16.0.64 acc4.i
172.16.0.65 acc5.i
172.16.0.71 web1.i
172.16.0.72 web2.i
172.16.0.73 web3.i
172.16.0.74 web4.i
172.16.0.75 web5.i
...
172.16.0.90 web20.i
172.16.0.91 mail1.i
172.16.0.92 mail2.i
172.16.0.93 mail3.i
172.16.0.94 mail4.i
172.16.0.95 mail5.i
172.16.0.101 monitor1.i
172.16.0.102 monitor2.i
172.16.0.103 monitor3.i
172.16.0.104 monitor4.i
172.16.0.105 monitor5.i
172.16.0.110 nfs1.i
172.16.0.111 nfs2.i
172.16.0.112 nfs3.i
172.16.0.113 nfs4.i
172.16.0.114 nfs5.i
172.16.0.121 pb1.i
172.16.0.122 pb2.i
172.16.0.123 pb3.i
172.16.0.124 pb4.i
172.16.0.125 pb5.i
172.16.0.221 search1.i
172.16.0.222 search2.i
172.16.0.223 search3.i
172.16.0.224 search4.i
172.16.0.225 search5.i
172.16.0.226 search6.i
172.16.0.227 search7.i
172.16.0.228 search8.i
172.16.0.229 search9.i
172.16.0.230 search10.i
172.16.0.231 queue1.i
172.16.0.232 queue2.i
172.16.0.233 queue3.i
172.16.0.234 queue4.i
172.16.0.235 queue5.i
172.16.0.236 queue6.i
172.16.0.237 queue7.i
172.16.0.238 queue8.i
172.16.0.239 queue9.i
172.16.0.240 queue10.i