127.0.0.1

IPv4 addresses can be represented in several formats. This may be useful to store IP addresses in a more efficient way (for example, storing IPs as UNSIGNED INT requires less space and may be a faster solution) or to bypass some filters (for example, something doesn’t allow you to specify IPs from private range, but since it filters only quad-dotted IPv4 address representation you can specify IP as decimal number). Below are listed almost all formats as IP 127.0.0.1 can be represented (actually there are more formats, since you can mix multiple formats).

Description	Notation	Command Example
Decimal number	2130706433	ping 2130706433
Dotted-decimal notation	127.0.0.1	ping 127.0.0.1
Decimal.Octal.Hexadecimal.Decimal	127.0000.0x0.1	ping 127.0000.0x0.1
Hexadecimal number	0x7f000001	ping 0x7f000001
Dotted-hexadecimal notation	0x7f.0x0.0x0.0x1	ping 0x7f.0x0.0x0.0x1
Hexadecimal.Octal.Decimal.Hexadecimal	0x7f.0000.0.0x1	ping 0x7f.0000.0.0x1
Octal number	017700000001	ping 017700000001
Dotted-octal notation	0177.0000.0000.0001	ping 0177.0000.0000.0001
Octal.Decimal.Hexadecimal.Octal	0177.0.0x0.0001	ping 0177.0.0x0.0001
Decimal shorthand	127.1	ping 127.1
Hexadecimal shorthand	0x7f.0x1	ping 0x7f.0x1
Octal shorthand	0177.0001	ping 0177.0001
Decimal IPv4-mapped IPv6 address	::ffff:127.0.0.1	ping ::ffff:127.0.0.1
Hexadecimal IPv4-mapped IPv6 address	::ffff:7f00:0001	ping ::ffff:7f00:0001

There are some technical details about the network 127.0.0.1 and its subnet, as well as some details about IP itself. Please note that this information may contain inaccuracies or outdated data.

Name	Value
Address Block	127.0.0.0/8
Subnet Mask	255.0.0.0
Broadcast Address	127.255.255.255
Address Range	127.0.0.1 - 127.255.255.254
Number of IP Addresses	16 777 216
Number of Valid Hosts	16 777 214
Previous IP Address	127.0.0.0
Next IP Address	127.0.0.2

The IETF and IANA have reserved some IPv4 addresses to be used for special purposes, and the IP 127.0.0.1 is one of them. The special-purpose IPv4 addresses are not intended for global routing (Internet) and are only used on local networks.

Attribute	Value	Description
Name	Loopback	A descriptive name for the special-purpose address block.
RFC	RFC1122, Section 3.2.1.3	The RFC through which the special-purpose address block was requested.
Allocation Date	September 1981	The date upon which the special-purpose address block was allocated.
Source	No	127.0.0.1 is invalid source address of an IP datagram that transits two devices.
Destination	No	127.0.0.1 is invalid destination address of an IP datagram that transits two devices.
Forwardable	No	A router may not forward an IP datagram to 127.0.0.1 between external interfaces.
Globally Reachable	No	An IP datagram to 127.0.0.1 is not forwardable beyond a specified administrative domain.
Reserved-by-Protocol	Yes	The special-purpose address block is reserved by IP, itself.

Dozens of companies are managing lists of blocked IP addresses in order to stop spamming, unethical hacking, and other malicious actions. These blacklists (also known as DNSBL and RBL) can contain both IP addresses and domains. Below we will try to lookup IP 127.0.0.1 through several backlists and find out who considers this IP to be malicious. Click DNSBL Lookup to get real-time data.

DNSBL Server	Listed	FQDN
all.s5h.net	Unknown	1.0.0.127.all.s5h.net.
b.barracudacentral.org	Unknown	1.0.0.127.b.barracudacentral.org.
bl.spamcop.net	Unknown	1.0.0.127.bl.spamcop.net.
blacklist.woody.ch	Unknown	1.0.0.127.blacklist.woody.ch.
bogons.cymru.com	Unknown	1.0.0.127.bogons.cymru.com.
cbl.abuseat.org	Unknown	1.0.0.127.cbl.abuseat.org.
combined.abuse.ch	Unknown	1.0.0.127.combined.abuse.ch.
db.wpbl.info	Unknown	1.0.0.127.db.wpbl.info.
dnsbl-1.uceprotect.net	Unknown	1.0.0.127.dnsbl-1.uceprotect.net.
dnsbl-2.uceprotect.net	Unknown	1.0.0.127.dnsbl-2.uceprotect.net.
dnsbl-3.uceprotect.net	Unknown	1.0.0.127.dnsbl-3.uceprotect.net.
dnsbl.anticaptcha.net	Unknown	1.0.0.127.dnsbl.anticaptcha.net.
dnsbl.dronebl.org	Unknown	1.0.0.127.dnsbl.dronebl.org.
dnsbl.inps.de	Unknown	1.0.0.127.dnsbl.inps.de.
dnsbl.sorbs.net	Unknown	1.0.0.127.dnsbl.sorbs.net.
dnsbl.spfbl.net	Unknown	1.0.0.127.dnsbl.spfbl.net.
drone.abuse.ch	Unknown	1.0.0.127.drone.abuse.ch.
duinv.aupads.org	Unknown	1.0.0.127.duinv.aupads.org.
dul.dnsbl.sorbs.net	Unknown	1.0.0.127.dul.dnsbl.sorbs.net.
dyna.spamrats.com	Unknown	1.0.0.127.dyna.spamrats.com.
dynip.rothen.com	Unknown	1.0.0.127.dynip.rothen.com.
http.dnsbl.sorbs.net	Unknown	1.0.0.127.http.dnsbl.sorbs.net.
ips.backscatterer.org	Unknown	1.0.0.127.ips.backscatterer.org.
ix.dnsbl.manitu.net	Unknown	1.0.0.127.ix.dnsbl.manitu.net.
korea.services.net	Unknown	1.0.0.127.korea.services.net.
misc.dnsbl.sorbs.net	Unknown	1.0.0.127.misc.dnsbl.sorbs.net.
noptr.spamrats.com	Unknown	1.0.0.127.noptr.spamrats.com.
orvedb.aupads.org	Unknown	1.0.0.127.orvedb.aupads.org.
pbl.spamhaus.org	Unknown	1.0.0.127.pbl.spamhaus.org.
proxy.bl.gweep.ca	Unknown	1.0.0.127.proxy.bl.gweep.ca.
psbl.surriel.com	Unknown	1.0.0.127.psbl.surriel.com.
relays.bl.gweep.ca	Unknown	1.0.0.127.relays.bl.gweep.ca.
relays.nether.net	Unknown	1.0.0.127.relays.nether.net.
sbl.spamhaus.org	Unknown	1.0.0.127.sbl.spamhaus.org.
singular.ttk.pte.hu	Unknown	1.0.0.127.singular.ttk.pte.hu.
smtp.dnsbl.sorbs.net	Unknown	1.0.0.127.smtp.dnsbl.sorbs.net.
socks.dnsbl.sorbs.net	Unknown	1.0.0.127.socks.dnsbl.sorbs.net.
spam.abuse.ch	Unknown	1.0.0.127.spam.abuse.ch.
spam.dnsbl.anonmails.de	Unknown	1.0.0.127.spam.dnsbl.anonmails.de.
spam.dnsbl.sorbs.net	Unknown	1.0.0.127.spam.dnsbl.sorbs.net.
spam.spamrats.com	Unknown	1.0.0.127.spam.spamrats.com.
spambot.bls.digibase.ca	Unknown	1.0.0.127.spambot.bls.digibase.ca.
spamrbl.imp.ch	Unknown	1.0.0.127.spamrbl.imp.ch.
spamsources.fabel.dk	Unknown	1.0.0.127.spamsources.fabel.dk.
ubl.lashback.com	Unknown	1.0.0.127.ubl.lashback.com.
ubl.unsubscore.com	Unknown	1.0.0.127.ubl.unsubscore.com.
virus.rbl.jp	Unknown	1.0.0.127.virus.rbl.jp.
web.dnsbl.sorbs.net	Unknown	1.0.0.127.web.dnsbl.sorbs.net.
wormrbl.imp.ch	Unknown	1.0.0.127.wormrbl.imp.ch.
xbl.spamhaus.org	Unknown	1.0.0.127.xbl.spamhaus.org.
z.mailspike.net	Unknown	1.0.0.127.z.mailspike.net.
zen.spamhaus.org	Unknown	1.0.0.127.zen.spamhaus.org.
zombie.dnsbl.sorbs.net	Unknown	1.0.0.127.zombie.dnsbl.sorbs.net.
spamguard.leadmon.net	Unknown	1.0.0.127.spamguard.leadmon.net.
rbl-plus.mail-abuse.org	Unknown	1.0.0.127.rbl-plus.mail-abuse.org.
httpbl.abuse.ch	Unknown	1.0.0.127.httpbl.abuse.ch.
combined.njabl.org	Unknown	1.0.0.127.combined.njabl.org.
rbl.efnetrbl.org	Unknown	1.0.0.127.rbl.efnetrbl.org.
cbl.anti-spam.org.cn	Unknown	1.0.0.127.cbl.anti-spam.org.cn.
bl.spamcannibal.org	Unknown	1.0.0.127.bl.spamcannibal.org.
rbl.suresupport.com	Unknown	1.0.0.127.rbl.suresupport.com.
csi.cloudmark.com	Unknown	1.0.0.127.csi.cloudmark.com.
rbl.interserver.net	Unknown	1.0.0.127.rbl.interserver.net.
virbl.bit.nl	Unknown	1.0.0.127.virbl.bit.nl.
short.rbl.jp	Unknown	1.0.0.127.short.rbl.jp.
blackholes.mail-abuse.org	Unknown	1.0.0.127.blackholes.mail-abuse.org.
truncate.gbudb.net	Unknown	1.0.0.127.truncate.gbudb.net.
query.senderbase.org	Unknown	1.0.0.127.query.senderbase.org.
opm.tornevall.org	Unknown	1.0.0.127.opm.tornevall.org.
netblock.pedantic.org	Unknown	1.0.0.127.netblock.pedantic.org.
access.redhawk.org	Unknown	1.0.0.127.access.redhawk.org.
cdl.anti-spam.org.cn	Unknown	1.0.0.127.cdl.anti-spam.org.cn.
multi.surbl.org	Unknown	1.0.0.127.multi.surbl.org.
dsn.rfc-ignorant.org	Unknown	1.0.0.127.dsn.rfc-ignorant.org.
dnsbl.njabl.org	Unknown	1.0.0.127.dnsbl.njabl.org.
relays.mail-abuse.org	Unknown	1.0.0.127.relays.mail-abuse.org.
rbl.spamlab.com	Unknown	1.0.0.127.rbl.spamlab.com.
all.bl.blocklist.de	Unknown	1.0.0.127.all.bl.blocklist.de.

If the IP 127.0.0.1 has aggressive behavior or should not have access to your private resources, you can block/ban it using your firewall, webserver, or programming language. Below are some examples of how to restrict this IP address from accessing your machine.

Algorithm	Example
Apache	<RequireAll>   Require all granted   Require not ip 127.0.0.1 </RequireAll>
iptables	iptables -A INPUT -s 127.0.0.1 -j DROP
Nginx	location / {   deny 127.0.0.1; }
Node.js	if (request.connection.remoteAddress === '127.0.0.1') {   return console.log(403); }
PHP	if (filter_input(INPUT_SERVER, 'REMOTE_ADDR') == '127.0.0.1') {   return print(403); }
Python	if (os.environ['REMOTE_ADDR'] == '127.0.0.1')   return print(403);
web.config	<security>   <ipSecurity allowUnlisted="true">     <add ipAddress="127.0.0.1"/>   </ipSecurity> </security>

Algorithm	Encoding Result
Ascii85	0et[?0J5%30`
Base64	MTI3LjAuMC4x
Binary	1111111000000000000000000000001
Morse Code	.----..-----...  .-.-.-  -----  .-.-.-  -----  .-.-.-  .----
Phonetic	One Two Seven Dot Zero Dot Zero Dot One
Uuencode	),3(W+C`N,"XQ `

Hashing algorithms are one-way functions that do not have a reversible algorithm. Most commonly they are used to check data integrity, prevent the data forgery, and hide sensitive information. For example, some developers may hash the clients IP addresses, that is why below are listed hashes of different hashing algorithms for IP 127.0.0.1.

Algorithm	Hash Value
md2	2a997b867e17233c2445f31d1bf39e61
md4	ff3541381e2391d53bba00dc93aed0e1
md5	f528764d624db129b32c21fbca0cb8d6
sha1	4b84b15bff6ee5796152495a230e45e3d7e947d9
sha224	a589d1f8fbfa428d037a55bd5d5373a834efc4591ac40dd96558c91f
sha256	12ca17b49af2289436f303e0166030a21e525d266e209267433801a8fd4071a0
sha384	e9568e3cf2427b7fa3cb353d86ca94459804d7e8842947cebdb06bb39803b9a5e2e7cb1db9f97433c33d322072f3d6c2
sha512	2f8748abdbb42c16f5d62251f8adea1f65443b6ed0ec063b49be332a6c8cc200892828deee3bbc44bffff040677446dfe0fe5d9dc5a2150d342dd93456b54e22
ripemd128	475cb1af08c5c5123d600e85a96092fb
ripemd160	d5120b6886a7e2ad811f81ab371b3909d88552d3
ripemd256	f267d344867154b3daace788192570c8d450375d5be101bd5424a14ccb86f05d
ripemd320	43a84f4bf7e73f6503d5c4748cb72243478e76d729d3bd3c7b12aa460fb4cd648b09a4e662a409c0
whirlpool	d0d4b981952f59071e5610efcdb239ecdbaecb5c82420523e5ca73ffeb276340eb50c75ad6a5db562d6705de5ead1f0dd4be2a32d192543647579bbe0b2ca408
tiger128,3	fdcb2fcfc122db155bb7c280a49bd6b6
tiger160,3	fdcb2fcfc122db155bb7c280a49bd6b65987ad5f
tiger192,3	fdcb2fcfc122db155bb7c280a49bd6b65987ad5f42937cd4
tiger128,4	ff93a63273cb86fcc4a5dc4bf201c504
tiger160,4	ff93a63273cb86fcc4a5dc4bf201c504e60fb387
tiger192,4	ff93a63273cb86fcc4a5dc4bf201c504e60fb387a0983ced
snefru	a185b7fc86372c1ab936d4024b2b8bfc5269a7f42cb0a975fb4eacad31816f56
snefru256	a185b7fc86372c1ab936d4024b2b8bfc5269a7f42cb0a975fb4eacad31816f56
gost	80264e6a2d8f576c96b6b9d1e3837ef8e4fba8134d9d8b9c64b3585b728b3ae4
gost-crypto	f0825cdbb6bd6551708b9e4b5c8530be2950885f4176844b2337beb0068167a1
adler32	08ac01b6
crc32	d3c0c72d
crc32b	d7b7e7a8
fnv132	0a3cffd8
fnv1a32	08a3d11e
fnv164	34ad3b1041204318
fnv1a64	aabafe7104d914be
joaat	f1de3b5a
haval128,3	7f29abe0808591dfee0099c776307074
haval160,3	c337ccb87015b8cf045de2cc48cd62e025476fb8
haval192,3	647a66ae067e0c2a623610b6f7d44e5fbf4107121528cc08
haval224,3	4fccdee53ed4dff2f4ea6fa4f0205c70e14a4a8b95a627cd21e814a3
haval256,3	58534a0aa0ca1eb0c42ee35f5db14d7c8f48439628b8702fbf40bc8c8a019edf
haval128,4	d080501be51b70cc452326d2aeda7ae5
haval160,4	26ad41e7b016ca47a0250493210dadc4a6c9a9a8
haval192,4	0a67fd43f762a7a4917e634adceb014a8d02bee6f3a5b2af
haval224,4	b7dd0737c4e30b45ecc24bc64acc5e80943e216520775309c3ba225c
haval256,4	0469cd349c2532a3a0d058ba71421a348e3f76fbbe811310e039f9276615d05a
haval128,5	834bc1d9779b841d3cc0c34f16bd0593
haval160,5	fabab34a611aad883601e3cbdb7a006d0255e3fc
haval192,5	c8b58348685e3da78d0f770290cf5913df6abc1a2a1d0c80
haval224,5	22abcccd9457d5102787678a735c77cc3a3f752b8aece0c63587ae61
haval256,5	b4d3c8473d1b184dfcd4811efda03fbff53fe71736c633962223593670c35b9a

Barcodes are widely used almost everywhere in the world, and this website is not an exception. Since barcodes are representing data in a machine-readable form, they are make life easier for people who are trying to interact and communicate with various devices. To make this website a little more useful for both people and machines, below are provided the most popular barcodes for IP 127.0.0.1.

Symbology	Barcode Image
QR Code
Codabar
ITF-14
Data Matrix
UPC-A
Code 39
EAN-8