On a PPPoE server we have enabled all 4 authentication types
(1) pap
(2) chap
(3) mschap1
(4) mschap2
Is all 4 required and is there any performance improvement by not using them all?
Any single one will do if all clients support it, and no, there is no performance impact if you keep all of them permitted - only one is used for each connection, and only once when the connection establishes. Some of them are considered more secure, though (mschap2 is the newest one and should be the most secure, but it’s all relative).