00299nam a2200109 a 450000500170000002000150001708200150003210000230004724500430007026000520011330000240016520251203110736.0  a0123116333  a005.8bHAR  aHarrington, Jan L.  aNetwork SecuritybA Practical Approach  aSan FranciscobMorgan Kaufmann Publishersc2005  axv,365p.c26 cm. PB