Suppose I enter Thailand via plane with italian passport, under the visa exemption/waiver (which guarantees me 30days in Thailand). Then I want to travel to Laos by land and come back to Thailand by land after couple of days. Questions:

1. Do I need any sort of re-entry permit to travel out and back in Thailand?

2. Does re-entering by land affect my initial 30days visa waiver?

Suppose I enter Thailand by air with an Italian passport, under the visa exemption (which guarantees me 30 days in Thailand). Then I want to travel to Laos by land and come back to Thailand by land after a couple of days.

1. Do I need any sort of re-entry permit to travel out and back in Thailand?
2. Does re-entering by land affect my initial 30 days visa waiver?