TeamViewer can punch through a double NAT. Instead of relying on macOS, you can turn to third-party remote access software, although my favorites have faded away and left active development, while ones that used to have free or affordable flavors have gone commercial and expensive. (In my case, the provided modem has some obscure networking features used by CenturyLink’s fiber-optic network.) All outbound connections work fine, but inbound ones can be a mess. If you connect, say, an AirPort Extreme with DHCP and NAT enabled to a LAN port on the ISP’s modem, you’re creating a NAT inside a NAT.

A double NAT happens typically when an ISP provides a modem that also acts as a router, and which has features you can’t replicate or turn off. Warning! Always set a strong password for VNC, as it’s easy for attackers to scan for VNC and find yours if it’s reachable from the Internet.īack to My Mac fails with “double NAT” situations, which I unfortunately have and which aren’t entirely rare. Third-party macOS and iOS apps let you access any VNC-capable system.Įnable screen sharing in the Sharing system preference pane, and click the Computer Settings buttons to turn on VNC. (Just to be more confusing, Apple’s Screen Sharing app is based on VNC, but not identical.) VNC can work over Back to My Mac, but doesn’t always, as it’s not a supported feature.

Instead of Back to My Mac and the Screen Sharing app, you can use the generic screen-sharing protocol VNC. Screen Sharing in macOS lets you use the built-in version as well as enable VNC.

How to remote into a mac from mac