00278nam a2200109 a 450000500170000002000150001708200150003210000230004724500430007026000300011330000250014320251203110741.0  a0123116333  a005.8bHAR  aHarrington, Jan L.  aNetwork SecuritybA Practical Approach  aNew DelhibElsevierc2006  axv, 365p.c24 cm. PB