"Crossover" - in the mirror universe, the Klingon-Cardassian Alliance controls the "entire quadrant." In "Prophet Motive," Quark suggests the Nagus's plans involve taking financial control of the "entire quadrant."
"Visitors" - Deep Space Nine is "hundreds of light years" from Earth. "Family Business" places Cestus III as being on the other end of the Federation from Deep Space Nine.
"For the Cause" - dozens of Cardassian worlds have lost their industrial bases to Klingon raids.
"Favor the Bold" - there is a Vulcan border.
"Statistical Probabilities" - the Jack pack was "carted halfway across the quadrant." They project 900 billion casualties upcoming in the Dominion War.
Map seen in "Waltz." The Defiant would take twelve hours to reach, and two starships several days to search the area. Map seen in "In the Pale Moonlight." Map seen in "The Reckoning."
Red Squad is sent on a training mission - to circumnavigate the entire Federation. Eight months later, they're running around enemy territory, and can't figure out how to get past warp 3.2.