Comment 1 for bug 171491

This is an older wish, but would still be a great feature.

A way to "link" two nodes of two different (or the same) paths, so that moving one of them also moves the second one and (optionally) also give them the same curve/bezier settings.

Example:
Two lines with different styles (so you cannot combine them to one Object), and you wand the first line to end exactly where the second starts. In this drawing, you want B to be at the same position as C:

  Line 1 Line 2
 A------B C========D

Moving line 2 should also update point B, but NOT point A, so grouping or selecting both is not an option.

This extension would probably not be SVG compliant. However, it would only affect the editing of the drawing, not the displaying itsself, and might be stored in an "Inkscape only" part of the document. It would would help editing a lot, in cases the OP noted (networks; longer paths that change style), but also in geometrical drawings ("I want line A to end in the middle of line B, even if I move that second line").

Summary: Linking two nodes of two probably different paths, so they always have the same position and (optionally) the same handle setting.