I am assisting a friend who has lost a phone and is considering getting an older phone (iPhone 7) as replacement, as it is well regarded in the digital photography profession.

The concern is that the router at their place, latest Comcast product, may produce issues with a legacy phone, such as the iPhone 7.

Are there any known issues with a latest model Comcast router and older Apple iPhones? How old of a phone model could they go? iPhone 6 or 5, perhaps?

They are concerned that the router may combine both 2.4 GHz and 5 GHz signals that the phone may have difficult connecting because it can't distinguish between both signal types.

  • 1
    2.4 and 5GHz shouldn't be a problem. The problem would be if the phone only had 2.4 and the router only 5. Why would there a problem otherwise?
    – ChanganAuto
    Aug 12, 2021 at 22:50
  • Only IPhone 6s and newer is supported by the current version of iOS. That likely will change with the release of iOS 15. Questions about iPhone are out of scope. As your question is primarily about the iPhone itself and doesn’t have anything to do with connecting it to a PC your question is out of scope here at Super User.
    – Ramhound
    Aug 13, 2021 at 4:12

2 Answers 2


I wouldn't yet consider the iPhone 7 to be a 'legacy smart phone', especially seen as Apple is still continuing to push software updates for it.

In terms of capability, the iPhone 7, like most devices released before February of last year, uses Wi-Fi 5. The most recent revision is Wi-Fi 6 which is backwards compatible with Wi-Fi 5, so everything should just work!

The only issue that could occur is that, very rarely, if someone purposefully change the settings of the router, it may be misconfigured to only allow connections over Wi-Fi 6. To fix this you'll have to go into the router's settings and change it back.


I have iPhones 6, SE running on both 2,4 GHz and 5 GHz modern router.

I had problems with the last iOS updates. Apple for privacy protection choosed to switch to dynamically attributed MAC ( Medium Access Control ) address. They recently added a function to inactivate this function and everything is again working fine on all our iPhones on a modern Wi-Fi router: an iMac running all 802.11*, a DHCP server, and a high grade firewall, within a crowded Wi-Fi environnement ( more than 40 neighbors networks ).

An iPhone 7 won't have any problem with a router up to the latest 802.11* protocols specification on whichever channel ( 2.4 GHz and 5 GHz ).

( Personnal waranty from my 30 years experience on network and security architecture. )

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