How long do ethernet cables last?

[dacq]

I'm thinking of getting a spare one in case.

[rich2005]

That is a strange question or are you just practising posting ?
How long do they last ? Forever or until you damage it.

They are cheap, get a spare, length depends on requirement.

A more up-to-date problem is, does your computer actually have an ethernet port. There are adaptors.

   

[Ofnuts]

Basically forever if you leave them plugged, otherwise sooner or later that little plastic tab will break.

Which doesn't mean you shouldn't replace them... Because the Cat 4 wiring that you installed in the 90s to support your 10Mb/s Ethernet won't be good enough to support early 00s 100Mb/s Ethernet (Cat 5), itself replaced in the later 00s by Gigabit Ethernet (Cat 5e or Cat6), so as you upgrade your devices, you should upgrade your wiring.

[Tas_mania]

Cat wiring is often in the wall cavities of offices and some homes with cat outlet plugs in the wall.
I recently discovered my RoboVac gets tangled in wires along the floor including it's own base station. I used cable ties and lifted them higher.