199.21.0.0 - 199.21.14.0 BroMenn Healthcare (NETBLK-TBLK-BROMENN) 199.21.16.0 - 199.21.31.255 Shared Medical Systems (NETBLK-TBLK-SMSNET) 199.21.32.0 - 199.21.63.0 GMAC Residential Funding Corporation (NETBLK-TBLK-GMACRFCNET)