Which of the following are types of internet connections?

SLIP, DIAS and PPP are all genuine internet connection methods, covering every item named here.

SLIP, the Serial Line Internet Protocol, was an early way to run IP over a serial link.

DIAS refers to a direct internet access service offered over leased lines.

PPP, the Point-to-Point Protocol, largely replaced SLIP with added features and error checking.

These define how a device negotiates and maintains an internet link.

PPP also supports authentication and works over many physical media.