'Taken from PCredz, solely to get Kerb parsing
working until I have time to analyze Kerb pkts
and figure out a simpler way
Maybe use kerberos python lib'

def Decode_Ip_Packet(self, s):

    d = {}
    d['header_len'] = (ord(s[0]) & 15)
    d['data'] = s[(4 * d['header_len']):]
    return d
