Guides
Fix your Mac’s network.
139 guides: recipes for jobs you can do with Kilobat, fixes for common macOS network problems and error messages, and what the macOS processes in your network list do.
Kilobat recipes
Jobs you can do with Kilobat: in the app, in Terminal and through an AI agent.
See which app uses data on a hotspotKilobat shows the upload and download of each app on your Mac.Stop updates from using hotspot dataOn a metered network, Kilobat can pause the helpers that download updates.Set a monthly data budget that resets on renewal dayA Kilobat budget belongs to one network.Compare Kilobat with your carrier's data figureYour carrier and Kilobat count different things.Keep your Mac awake until a download finishesKilobat keeps the Mac awake while transfers run.Keep an agent running with the lid closedClosing the lid puts a Mac laptop to sleep.Find why one site or API won't connectWhen the internet works but one address fails, Kilobat checks each layer in turn.Check the network before a big download in an agentAn agent can ask Kilobat if now is a good time for a large transfer.Find a better Wi-Fi spotThe signal radar scores your Wi-Fi several times a second.Test for call stutterA speed test averages its pings, so short spikes disappear.Share Wi-Fi with a QR codeKilobat makes a QR code from the saved password of a network.Pick a faster DNSSlow DNS makes every new site slow to start.Block an app on metered networksThe Travel profile allows only the apps that you choose.Get approvals for new appsIn Ask mode, Kilobat holds the first connections of an app that has no rule.Tell Kilobat when an agent waits or is doneWithout hooks, Kilobat sees an agent only by its traffic and CPU.See where your apps connectKilobat shows the open connections of each app and the country where each address is registered.Find out why two speed tests differTwo speed tests can disagree for many reasons.See if traffic goes through your VPNKilobat reads the Mac's routes to show whether traffic leaves through a VPN.
Wi-Fi
Drops, slow links, bands, interference and the Mac's own Wi-Fi tools.
Mac Wi-Fi disconnects after sleepAfter sleep, the Mac must join the Wi-Fi network again.Wi-Fi is slow on the Mac but fast on the phoneWhen the phone is fast on the same network, the internet connection is not the problem.2.4 GHz, 5 GHz and 6 GHz Wi-Fi on a MacWi-Fi uses three bands.Bluetooth headphones and Wi-Fi interference on a MacBluetooth and 2.4 GHz Wi-Fi use the same radio band.AirDrop, AWDL and latency spikes in games and callsAWDL is the Apple Wireless Direct Link.Weak Wi-Fi signal on a MacSignal strength and noise decide how fast and how stable the Wi-Fi link is.Crowded Wi-Fi channels near your MacNetworks on the same channel share the air time.Mac connected to Wi-Fi but no internetA Wi-Fi connection is only the link to the router.Mac joins the wrong Wi-Fi networkThe Mac joins known networks on its own.Find a saved Wi-Fi password on a MacThe Mac stores the password of each Wi-Fi network that it joins.Use Wireless Diagnostics and wdutil on a MacWireless Diagnostics is a Wi-Fi tool that comes with macOS.
Public Wi-Fi and privacy
Captive portals, private addresses, Private Relay and Wi-Fi security warnings.
“Weak security” warning on Mac Wi-FiThe Mac shows a security warning when a network uses an old security mode.Private Wi-Fi address on a MacA private Wi-Fi address replaces the hardware MAC address of the Mac on a network.Limit IP address tracking on a MacLimit IP address tracking is a setting for each network.iCloud Private Relay breaks some websitesiCloud Private Relay sends Safari traffic through two relays.Wi-Fi login page does not appear on a MacPublic networks often hold all traffic until you sign in on a login page.
DNS
Names that do not resolve, slow lookups, the DNS cache, VPN DNS and encrypted DNS.
DNS not resolving on a MacWhen DNS fails, the Mac cannot change a name such as apple.com into an IP address.Slow DNS on a MacEvery new site needs a DNS lookup before it can load.Flush the DNS cache on a MacmacOS keeps DNS answers for some time.DNS queries go outside the VPN on a MacWith a VPN on, you usually want DNS queries to go to the VPN's servers.Use encrypted DNS on a MacNormal DNS queries are not encrypted.Changes to /etc/hosts do not work on a MacThe /etc/hosts file maps names to IP addresses on this Mac only.Internal names do not resolve on a VPNmacOS can send queries for one domain to one DNS server and other queries to another.
IP, routing and IPv6
Addresses, DHCP, service order, IPv6 and MTU.
IPv6 problems on a MacMost networks give a Mac both IPv4 and IPv6 addresses.MTU problems on a MacThe MTU is the largest packet that an interface sends.Mac has a self-assigned IP addressIf the Mac gets no answer from a DHCP server, it gives itself a link-local address from 169.254.0.0/16.IP address conflict on a MacTwo devices on one network cannot use the same IP address.Renew the DHCP lease on a MacA DHCP lease gives the Mac its IP address, router and DNS servers.Mac uses the wrong network connectionWhen more than one connection is active, the Mac tries the service at the top of the list first.See Mac network settings in TerminalmacOS includes command-line tools that show the same network settings as System Settings, and more.
VPN, proxy and filters
VPNs, proxies, network extensions, content filters and certificates.
Proxy settings stop apps from connecting on a MacA proxy setting sends traffic through another server.Little Snitch, LuLu and other network extensions conflict on a MacFirewalls, VPNs and content filters on macOS use network extensions.A content filter blocks websites on a MacA content filter examines web traffic and blocks some sites.VPN connected but no internet on a MacA VPN sends traffic through a tunnel.Tailscale and another VPN conflict on a MacTailscale gives each device an address in 100.64.0.0/10.Corporate proxy certificates break Terminal tools on a MacSome company networks inspect HTTPS traffic.
Hotspots and data
Personal Hotspot, Low Data Mode, metered networks and background downloads.
Mac uses Personal Hotspot data in the backgroundA Mac on a phone hotspot can use a lot of data with no action from you.Use Low Data Mode on a MacLow Data Mode tells macOS and apps to use less data on one Wi-Fi network.Stop Software Update downloading on a hotspotmacOS can download updates on its own.Make a Mac treat a network as meteredmacOS marks some connections as expensive, such as an iPhone Personal Hotspot.iPhone hotspot does not show on the MacInstant Hotspot lets a Mac join your iPhone or iPad hotspot without a password.
Developers
Containers, VMs, localhost, ports, SSH, Git and package downloads.
Cannot reach a Docker container from the MacDocker on a Mac runs containers in a Linux virtual machine.A container cannot reach localhost on the MacEach container has its own network stack.SSH and Git time out on a MacSSH and Git need a working TCP connection to the server.Homebrew or npm downloads fail on a MacHomebrew downloads with curl and Git.Port already in use on a MacOnly one process can listen on a TCP port and address.Port 5000 or 7000 is in use on a Mac: AirPlay ReceiverApple lists TCP ports 5000 and 7000 for AirPlay.
Ethernet and tethering
Adapters, cables, link speed, USB tethering and Internet Sharing.
Connect a Mac to an iPhone hotspot with a USB cableA USB cable gives a Mac the iPhone's internet connection and charges the iPhone.Mac does not detect a USB or Thunderbolt Ethernet adapterA USB or Thunderbolt Ethernet adapter must appear as a hardware port and as a network service.Ethernet on a Mac is slower than expectedAn Ethernet link runs at the speed that both ends and the cable support.Share a Mac's internet connection with other devicesInternet Sharing lets other devices use the Mac's internet connection.
Sleep and power
Sleep, wake, caffeinate and running with the lid closed.
Keep a Mac awake from Terminal with caffeinateThe caffeinate command stops a Mac from sleeping while a task runs.Use Wake for network access on a MacWake for network access lets a sleeping Mac wake when another computer uses its shared resources.Mac sleep stops downloadsA Mac that goes to sleep stops most app activity, so a long download can stop or fail.Keep a Mac laptop working with the lid closedClosing the lid puts a Mac laptop to sleep.
Websites and speed
Sites that fail, certificate errors, slow internet, speed tests and call quality.
A website works on your phone but not on your MacWhen a site opens on your phone but not on your Mac, the problem is usually on the Mac.Safari can’t find the server on a Mac“Safari can’t find the server” usually means that the Mac could not get an address for the site name.“This Connection Is Not Private” and certificate warnings on a MacSafari shows a certificate warning when it cannot confirm the identity of a website.Slow internet on a Mac: find which part is slowA slow connection has many possible causes.Test internet speed from Terminal with networkQualitymacOS includes networkQuality, a command-line test.Bufferbloat: calls lag when the network is busyBufferbloat is latency that network devices add when they hold too much data in their buffers.Test for packet loss on a Mac with pingPacket loss makes calls break up and pages stall.Find where a connection slows down with traceroutetraceroute shows each router on the path from your Mac to a host, with the time each one takes to answer.Find which app uses your bandwidth on a MacActivity Monitor and nettop show which processes send and receive data.Video calls stutter or freeze on a MacCalls need steady latency and steady upload more than high speed.
Local network
Devices on the network, local network access and the macOS firewall.
An app cannot find devices on the local networkmacOS 15 Sequoia and later ask before an app connects to devices on your local network.The macOS firewall blocks incoming connectionsThe macOS firewall controls connections that other computers start to your Mac.Find the devices on your local network from a MacmacOS has two built-in ways to see other devices: the ARP table and Bonjour.
Error messages
The exact text of common network errors from Safari, Chrome, macOS and Terminal tools: causes in order, checks, then fixes.
“Safari can’t establish a secure connection to the server” on MacSafari shows this when the secure connection to the server fails before the page loads.“Safari can’t connect to the server” on MacSafari found the address of the site, but the connection to the server did not open.Safari: “You Are Not Connected to the Internet” on MacSafari shows this page when macOS has no internet connection for it.“The Internet connection appears to be offline.” on MacThis is the macOS text for error -1009 in the URL Loading System.“The network connection was lost.” on MacThis is the macOS text for error -1005.“A server with the specified hostname could not be found.” on MacThis is the macOS text for error -1003.“The request timed out.” on MacThis is the macOS text for error -1001.“Safari can’t connect to the web proxy server” on MacA web proxy is set in the network settings, and Safari cannot reach it.DNS_PROBE_FINISHED_NXDOMAIN in Chrome on MacChrome shows this code when a DNS lookup failed and its own check says the name does not exist.ERR_NAME_NOT_RESOLVED in Chrome on MacChromium describes this error as: “The host name could not be resolved.” Chrome could not get an address for the site's name.ERR_CONNECTION_TIMED_OUT in Chrome on MacChromium describes this error as: “A connection attempt timed out.” Chrome found the address, but the server did not answer in time.NET::ERR_CERT_DATE_INVALID in Chrome on MacThe server's certificate looks expired or not yet valid by the Mac's clock.ERR_NETWORK_CHANGED in Chrome on MacChromium describes this error as: “The network changed.” Chrome stopped the load because the Mac's network changed during it.ERR_INTERNET_DISCONNECTED in Chrome on MacChromium describes this error as: “The Internet connection has been lost.” Chrome found no working connection on the Mac.Wi-Fi says “No Internet Connection” on MacmacOS shows “No Internet Connection” under a Wi-Fi network when the Mac joined the network but cannot reach the internet through it.“Wi-Fi: No hardware installed” on MacmacOS shows this when it cannot find the Wi-Fi hardware.“curl: (6) Could not resolve host” on Maccurl exit code 6 means that curl could not get an address for the host name.Git: “Could not resolve host: github.com” on MacGit could not get an address for github.com.ssh: connect to host port 22: Operation timed out on Macssh sent a connection request to port 22 and got no answer.“npm error code ETIMEDOUT” on MacETIMEDOUT means that the other side did not answer in time.“npm error code ECONNRESET” on MacECONNRESET means that the other side closed the connection by force.Homebrew fails with “curl: (28)” on MacHomebrew downloads with curl.Mac has a self-assigned IP addressIf the Mac gets no answer from a DHCP server, it gives itself a link-local address from 169.254.0.0/16.IP address conflict on a MacTwo devices on one network cannot use the same IP address.Safari can’t find the server on a Mac“Safari can’t find the server” usually means that the Mac could not get an address for the site name.“This Connection Is Not Private” and certificate warnings on a MacSafari shows a certificate warning when it cannot confirm the identity of a website.
macOS processes
What a process in Activity Monitor or nettop is, why it uses the network, and the setting that controls it.
What is nsurlsessiond on Mac?nsurlsessiond is part of macOS.What is mDNSResponder on Mac?mDNSResponder answers DNS lookups for every app on the Mac, and it runs Bonjour on the local network.What is softwareupdated on Mac?softwareupdated is the macOS Software Update daemon.What are appstoreagent and appstored on Mac?appstoreagent and appstored support the App Store.What is cloudd on Mac?cloudd syncs app data with iCloud for apps that use CloudKit.What is bird on Mac?bird is one of the macOS daemons behind iCloud Drive.What is fileproviderd on Mac?fileproviderd connects cloud storage apps to the files in the Finder.What is AssetCache on Mac?AssetCache is the Content Caching service.What is mobileassetd on Mac?mobileassetd downloads system assets for macOS.What is cloudphotod on Mac?cloudphotod is the iCloud Photos agent.What is rapportd on Mac?rapportd lets your Mac talk to your other Apple devices.What is sharingd on Mac?sharingd runs AirDrop, Handoff, Instant Hotspot and the shared computers in the Finder.What is apsd on Mac?apsd keeps one connection open to the Apple Push Notification service.What is trustd on Mac?trustd checks certificates for all processes on the Mac.What is syspolicyd on Mac?syspolicyd is the system policy daemon.What is assistantd on Mac?assistantd is the Siri daemon.What is parsecd on Mac?parsecd supports search suggestions in Spotlight, Safari, Siri and Look Up.What is identityservicesd on Mac?identityservicesd is part of the Apple Identity Service.What is remotepairingd on Mac?remotepairingd connects the Mac to paired Apple devices.What are ReportCrash and SubmitDiagInfo on Mac?ReportCrash saves crash reports on the Mac.What is configd on Mac?configd keeps the network configuration of the Mac.What is netbiosd on Mac?netbiosd handles NetBIOS names for Windows-style networks.What is symptomsd on Mac?symptomsd provides services for Apple's Symptom Framework.What is timed on Mac?timed keeps the Mac's clock correct.What is locationd on Mac?locationd runs Location Services.What are findmydeviced and searchpartyd on Mac?findmydeviced is the Find My Mac daemon.What is privatecloudcomputed on Mac?privatecloudcomputed encrypts and sends some Apple Intelligence requests to Apple's Private Cloud Compute servers.What is GoogleUpdater on Mac?GoogleUpdater updates Chrome and other Google apps in the background.What is Microsoft AutoUpdate on Mac?Microsoft AutoUpdate (MAU) keeps Office, Teams and other Microsoft apps up to date.What is Autoupdate (Sparkle) on Mac?Autoupdate is part of Sparkle, an open source update framework that many Mac apps use.What is ShipIt on Mac?ShipIt comes from Squirrel.Mac.
Each guide lists its sources: Apple Support articles, Apple developer documentation and the man pages that ship with macOS, checked on 29 October 2026. Kilobat appears only where it helps, in a separate “With Kilobat” section.