cyberspace networking involves a lot of alchemy , and I confess to occasionally drop an middle of newt ( or an IP of triton ) into a stewing pot to fix job on my local connection . There ’s a particular message that macOS displays in limited case that is perplexing because it ’s the sort of low - level bubbling up that Apple generally takes care of . In this case , your Mac alerts you to a problem that may be of your making or might involve your Wi - Fi gateway or broadband modem . That message : “ Another gadget is using your IP address . ”
This conflict foreclose your computer from accessing some of the local meshing and from hit the internet . Here ’s why .
Every equipment that put across over the cyberspace needs a unequalled internet communications protocol ( IP ) reference , a number that is used by routers to package and mail datum to the good recipient . That ’s genuine on a LAN or within top - level internet data exchange , whether it ’s a $ 10 million router or an addressable smart lightbulb . When the internet first began its superfast increase over two decades ago , the addresses used came from a relatively small stove , using the IP version 4 ( IPv4 ) standard . The number of possible unique name and address was far modest than what the great unwashed predicted would be needed shortly , and that prognostication come true .
The TCP/IP view lets you set an address for your Mac, which could lead to picking one already in use.
internet Address Translation ( NAT ) was create as a means to volunteer LAN - plug into gadget something special while preserving the kitty of destination available . While most IP address have to be unique , because they ’re all used in a large public pool – like experience a alone street address in a singular city in a unique state or province – the NAT communications protocol allows forprivateaddresses that are pass away through gateway that map out the private address onto a shared public one . forthcoming dealings is make out by the router so that incoming responses are occur back to the correct calculator or other hardware on the LAN . It ’s a catchy outgrowth , but it ’s used for trillions ( perchance quadrillion ) of data packets a 24-hour interval globally .
Most routers partner off NAT with DHCP ( Dynamic Host Configuration Protocol ) , which mechanically assigns address to devices when asked . You ’ll note that when you tie to a Wi - Fi web or plug in via ethernet on your meshwork ( and on most web ) , you are n’t asked to configure IP preferences . Instead , your twist is set by default to broadcast out a query to the gateway over DHCP ; the gateway receives it , the NAT system finds an usable computer address and maintain a record of it , and the DHCP host provides that address and other preferences to your hardware , which is called a “ lease . ”
Here are several method acting to solve the destination - in - use problem .
The TCP/IP view lets you set an address for your Mac, which could lead to picking one already in use.
If you don’t manage your gateway
If a category member , booster , or fellow worker handle the gateway – even as bare as they ’re the one who has the password and they ’ve never touched it since setting it up – ask them for service and have them read this clause .
Power cycling the router might serve if it ’s a fracture in the router ’s internal tracking of addresses . Connecting to the router ’s administrative user interface can also assist in trouble-shoot what ’s conk out on .
Sleep and wake your Mac
If you ’ve never touched your gateway options , you’re able to simply try putting your Mac to catch some Z’s and waking it ; that sometimes exonerate a transient conflict . When the Mac backwash without an IP name and address , it tries to get the gateway ’s DHCP server to give it an address again , and it may just go .
You could attempt reboot your computer , but that step may not be require ; try the next result instead .
Renew DHCP lease
In macOS , use the web predilection dot or mount :
If this works , you ’re all set ( for now ) . If not , go along to check for other problems .
Manually configured address
Every equipment has to have a unique individual IP address on the local web , and if you ’ve manually configure your hardware ’s web setting to utilise a specific number , it ’s potential you ’re take in the “ Another equipment is using your IP speech ” alert because the DHCP / NAT combining has set apart out an address you set by hand for the computer you ’re on . ( Or , the other machine that ’s using it was manually configure and you or someone else needs to control that one . )
For example , you might be running a game server or need to screen share with your computer remotely , have read up on port mathematical function or UPnP ( Universal Plug ’ n ’ gambol ) , and configured your machine to have a fixed ( or “ static ” ) secret name and address so that it could always be reachable via some router magic trick . You might have , say , set your computer ’s address to be 192.168.1.100 .
Many gateway rent you set aside specific address ( sometimes called “ DHCP reservations ” ) to avoid re - using an IP on the web . Others allow you set the start of an IP range . So if the meshwork is 192.168.1.0 to 192.168.1.255 , you may set the start of NAT - assigned addresses to 192.168.1.100 , and take any uncommitted address from 192.168.1.2 to 192.168.99 . NAT will still make and DHCP is n’t involved . ( The .0 and .1 reference are usually reserved , so you may have to commence in this deterrent example at 192.168.1.2 . )
To check whether you ( or someone else ) configure your Mac this way in the past and simply bury about it , use the instruction above for renewing your DHCP lease to pilot to the TCP / IP section of your user interface ’s connection setting . In the TCP / IP pane or aspect , if the fructify forConfigure IPv4is Manually , the address was enter by hand . Check your gateway to see whether you could change the range there if you want or necessitate to keep this place setting .
The TCP / IP view let you set an address for your Mac , which could lead to picking one already in purpose .
If you do n’t screw why it ’s localize that way and it ’s not on a work web in which constitute a alteration might have an shock on carbon monoxide gas - worker , chooseUsing DHCPfrom the belt down - up menu , clickOK , and , in Monterey or earlier , clickApply , and see if the problem goes forth .
Not enough network addresses to hand out
Most routers are configured by default to offer somewhere between 100 and 200 addresses , because when the box seat was designed , supervise that quantity was within the processing capabilities of the gimmick or it was seen as a sensible identification number . An older gateway , however , might have been arrange by default or configured by an ISP ’s installer for as few as 50 dynamically assigned private address . In 2000 , who could reckon a hereafter in which more than 50 dissimilar pieces of computer hardware in a house would all call for to connect to the internet ? ! Ridiculous .
The DHCP host not only assign an address but also sequester an expiration meter to it . When the time run out , the twist can call for a raw reference or the server can renew if the gimmick is presently active on the web . Otherwise , that savoir-faire is freed up and goes back into the pool . In some cases , even with hundreds of usable private address , your gateway might run down its supply . It should n’t pass on out an identical address , but things could go wrong . ( You might get no reference , in which case your Mac creates a so - calledself - assigned IP address , which starts with 169.254.x.x . )
This exhaustion of number can pass off if you have a quite a little of internet - connected devices , share a home or building that has poorly make do internet service ( because they really should have more computer address usable or adept DHCP timeouts ) , or a lot of masses pass across your mesh .
take off with your router . Read the manual , lumber in to its administrative interface , and check its setting . It may show you a list of connected equipment and the assigned individual IP address . you could see if you ’re outmatch the routine it can assign , and may be able to simply increase that number . You may also be able to lower the timeout continuance , so that it frees up addresses quicker .
You might have to upgrade your router or make more complicated change , but that ’s unconvincing for place and small - business usage . On most gateways , you should be able to bump the number to over 200 or make change that lease you attribute out over 500 or over 1,000 .
This Mac 911 clause is in response to a question submitted by Macworld proofreader Humberto .
Ask Mac 911
We ’ve compile a list of the dubiousness we get asked most frequently along with answers and links to columns : read our super FAQto see if your question is covered . If not , we ’re always looking for new problems to clear ! e-mail yours tomac911@macworld.comincluding screen captures as appropriate , and whether you want your full name used . Not every motion will be answered , we do n’t reply to e-mail , and we can not allow direct troubleshooting advice .
