For hiking, the safest practical option is a well-padded camera backpack with adjustable dividers, placing the lens securely in the middle of the pack rather than loose at the bottom. Extra padding around and under the lens helps, and a snug fit matters so it cannot shift or take direct impact.

For air travel, avoid checking photo gear if you can. Checked baggage is generally the riskiest place for a lens. If you absolutely must check a large telephoto, use a hard case with substantial foam protection so the lens is immobilized and cushioned on all sides.

Simple fabric wrapping alone is usually not enough for a heavy telephoto. Because larger lenses have more mass, they benefit from better structure and impact protection than a casual wrap provides. Bubble wrap or added padding can help as a budget measure inside a backpack, but a proper padded backpack or hard case is the safer solution.

In short: for backpacking, use a padded camera backpack with the lens centered and immobilized; for flying, carry it on if possible, and only check it in a hard foam-lined case if necessary.