PMTUD Black Holes
Some firewalls incorrectly discard all ICMP packets, including the ones needed for Path MTU discovery to work correctly. This causes TCP connections from/to/through hosts with a lower MTU to hang.
Read more about this topic: Black Hole (networking)
Famous quotes containing the words black and/or holes:
“Black one, black one,
there was a white
candle in your heart.”
—Denise Levertov (b. 1923)
“A person taking stock in middle age is like an artist or composer looking at an unfinished work; but whereas the composer and the painter can erase some of their past efforts, we cannot. We are stuck with what we have lived through. The trick is to finish it with a sense of design and a flourish rather than to patch up the holes or merely to add new patches to it.”
—Harry S. Broudy (b. 1905)