Easterby made his first international appearance in a Six Nations victory over Scotland at Lansdowne Road in 2000 and then became a regular in the side, being ever-present for the remainder of that Six Nations competition. Easterby then played in all three of the games during the summer tour but he missed all of the following season due to injury and did not return until the game against Scotland in September 2001. After Ireland's defeat, he lost his place but he did win a cap as a replacement against Samoa in November 2001. In 2002 he played a part in the first ten of Ireland's games – eight as a starter – but after that, he lost his place and he did not return until playing in two Tests during the summer tour of 2003 against Tonga and Samoa.