Sapphire/Slammer worm: Impact on Internet performance Olaf Kolkman, RIPE NCC Using routine measurements from RIPE NCC's Test Traffic Measurement (TTM), Routing Information Service (RIS) and root-server monitoring projects we have measured the effect of the Sapphire/SQL slammer worm. Main conclusions are that - 60% of the measurement relations in the test traffic mesh were unaffected, this is an indication that most harm was done at the network edges and not on the backbone. - 2 out of the 11 root-servers were affected, the root-server system did not suffer.