Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

I have a question regarding when a unit is eligible to receive a cover save from an aegis defense line. Do they need to have a model from the unit in base-2-base with it? How far away can they be before (1) they no longer benefit and (2) before I benefit from it as well?

It all works off of true line of sight.

If 25% of any given model is covered by the defense line, from the view of any of the firing models, then that model receives a save.

Unit's don't receive cover saves, models do. You determine how much of the wounded model is in cover, using TLOS, when you allocate a wound, if it is 25% obscured it receives a cover save from whatever is obscuring it. So, you don't need to be in base contact with it to gain a cover save.

To answer 1, it depends on what your model can "see" of the enemy.
And to answer 2, it depends on what the enemy can "see" of your model.