I know that are adresses reserved for private networks. What about addresses and other.. in Are they routable in the "Internet" or are they also private?

5 Answers 5


These reserved IP-ranges for private networks are defined in RFC1918. is not in them. You can verify using a WHOIS service that this /16 is divided into a number of smaller assignments to various networks.


No it isn't. See RFC6890 for all Special-Purpose IP Address Ranges (IPv4 and IPv6)


What about

This is valid address space, and the addresses are routable, they are NOT private.

What about other addresses in

You'd have to verify with WHOIS, some of the networks other than within the range are also private.

You could check anything you like in the future from just about an Linux distribution command line via the WHOIS tool:

whois x.x.x.x/yy

Example of valid address space:

NetRange: -
NetName:        NET192
NetHandle:      NET-192-0-0-0-0
Parent:          ()
NetType:        Early Registrations, Maintained by ARIN
Organization:   Various Registries (Maintained by ARIN) (VR-ARIN)
RegDate:        1993-05-01
Updated:        2010-06-30
Ref:            http://whois.arin.net/rest/net/NET-192-0-0-0-0

OrgName:        Various Registries (Maintained by ARIN)
OrgId:          VR-ARIN
Address:        3635 Concord Parkway, Suite 200
City:           Chantilly
StateProv:      VA
PostalCode:     20151
Country:        US
RegDate:        1993-05-01
Updated:        2011-09-24
Comment:        Address space was assigned by the InterNIC regardless of
Comment:        geographic region.  The registrations are now being maintained
Comment:        by various registries, and the in-addr.arpa delegations are
Comment:        being maintained by ARIN.
Ref:            http://whois.arin.net/rest/org/VR-ARIN

Example of private address space:

Internet Assigned Numbers Authority PRIVATE-ADDRESS-CBLK-RFC1918-IANA-RESERVED (NET-192-168-0-0-1) -
Various Registries (Maintained by ARIN) NET192 (NET-192-0-0-0-0) -

From RFC1918 Section 3:

   The Internet Assigned Numbers Authority (IANA) has reserved the
   following three blocks of the IP address space for private internets:        -  (10/8 prefix)      -  (172.16/12 prefix)     - (192.168/16 prefix)
1 is the only private address space in is used by IANA, is reserved for documentation and examples, and is for 6to4 anycast.

See: http://en.wikipedia.org/wiki/Reserved_IP_addresses https://www.arin.net/knowledge/address_filters.html


I know that are adresses reserved for private networks.


What about addresses

Those are regular public IPv4 addreseses allocated to various networks.

and other.. in Are they routable in the "Internet" or are they also private?

Most of the block is regular public IPs but there are a number of special things in there. Special allocations are documented at http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml is reserved for IETF protocol assignments. is reserved for clients of ds-lite 464xlat and similar is reserved as a dummy address for 4rd is an anycast address for "port control protcol" and are used for DNS64 discovery is reserved for documentation, examples etc is used for "AS112 Redirection Using DNAME" is used for "Automatic Multicast Tunneling" is used as an anycast prefix for 6to4 relays is private use is Direct Delegation AS112 Service

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