I believe it is Egypt that is blockading the Gaza-Egypt border. But according to this AFP photo caption, reprinted on Andrew's blog, it is Israel that is responsible for Egypt's border with Gaza:
Palestinians smuggle sheep into the Gaza Strip through a tunnel under the Egypt-Gaza border in Rafah on November 15, 2009. Residents of the poverty-stricken Gaza Strip fear a shortage of sacrificial cattle ahead of a major Muslim holiday due to Israel's blockade. Eid al-Adha or Feast of Sacrifice marks the end of the annual pilgrimage to Mecca and is celebrated in remembrance of Abraham's readiness to sacrifice his son to God. By Said Khatib/AFP/Getty.