As stated by Daniel B in his answer, the 1.1.1.1
address is currently assigned to APNIC labs (as it was when the question has been asked). However, until January 2010, the 1.0.0.0/8
network block, of which 1.1.1.1
is part, was unassigned and therefore (ab)used for local use in several cases.
Although the network block has been now assigned to APNIC (and addresses starting with 1.
are now definitely in use), several old pieces of equipment persist in using 1.1.1.1
for local purposes, and perhaps in consequence of this, a small block of 256 IP addresses (1.1.1.0
to 1.1.1.255
) has been reserved for research purposes by APNIC labs.
No route for the 1.1.1.0/24
prefix containing 1.1.1.1
has ever been announced on BGP (see https://stat.ripe.net/1.1.1.1#tabId=at-a-glance for details, in particular 1.1.1.1 was never globally visible as exact match in BGP by any of the RIS peers since beginning of 2004. No less-specific covering prefixes.
), which means that the address has never been used for a publicly-facing service. This of course does not mean that this will never happen.
The fact that you can have a traceroute to 1.1.1.1
that responds with the gateway address can come from two sources:
- The gateway figures out that the address can't be routed because there is no route announcement for it, and therefore answers with an ICMP "unreachable" message -- however your traceroute should in this case display a specific marking (e.g.
!H
). I would say that this explanation is not very probable, because your gatweay will probably only forward packets to the next router.
- The
1.1.1.1
address is still used locally by some equipment (see below).
Among unofficial uses of the 1.1.1.1
address, or of an address block containing it:
- Some equipment from several manufacturers (including Cisco and ZyXel) is still using the
1.1.1.1
address for local purposes (for example, login portals for public WiFi connections, local management networks, etc.). You can perhaps see what the equipment is by going to https://1.1.1.1/ with your browser. Also check the address of your DHCP or DNS server to see if one of those is 1.1.1.1
.
- Fastweb, an Italian ISP (but probably other providers too), was in the past assigning IPs in the
1.0.0.0/8
network to their customers, but since that network range became public, they switched to a more classic private IP range (10.0.0.0/8
).
UPDATE (April 11th 2018) — As per Bob's comment to another message, there is now a public DNS service on 1.1.1.1. See also https://1.1.1.1/ for more information about what this is. So this address is now definitely off-limits for private use! (as it should always have been).
$ ping 1.1.1.1
PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
64 bytes from 1.1.1.1: icmp_req=1 ttl=57 time=4.67 ms
64 bytes from 1.1.1.1: icmp_req=2 ttl=57 time=4.20 ms
64 bytes from 1.1.1.1: icmp_req=3 ttl=57 time=4.19 ms
64 bytes from 1.1.1.1: icmp_req=4 ttl=57 time=4.17 ms
^C
--- 1.1.1.1 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3030ms
rtt min/avg/max/mdev = 4.179/4.313/4.677/0.210 ms