Here is my latest NIPR/SIPR network frequency/station list. Traffic on these frequencies is mostly encrypted message traffic with stations using ALE to sound.
SIPR (Secret Internet Protocol Router) Network Frequencies
(USB/ALE): 3113.0 5702.0 5902.0 6715.0 8968.0 9044.0 11181.0 15091.0 17976.0 27870.0 kHz.
SIPR Gateway/Frequency Matrix
ADWSPR Andrews AFB, Maryland 3113.0 5702.0 6715.0 8968.0 9044.0 11181.0 17976.0 27870.0
AEDSPR Elmendorf AFB, Alaska 6715.0 17976.0
CROSPR Croughton AB, United Kingdom 5702.0 5902.0 6715.0 8968.0 11181.0 15091.0 17976.0 27870.0
GUASPR Andersen AB, Guam 5702.0 8968.0 11181.0 15091.0
HAWSPR Ascension Island 5702.0 6715.0 8968.0 11181.0 15091.0 17976.0 27870.0
HIKSPR Hickam AFB, Hawaii 5702.0 5902.0 6715.0 8968.0 15091.0
ICZSPR Sigonella AB, Sicily, Italy 5702.0 6715.0 8968.0 11181.0 15091.0 17976.0
JDGSPR Diego Garcia, Indian Ocean 5702.0 6715.0 8968.0 9044.0 11181.0 27870.0
JNRSPR Salinas, Puerto Rico 3113.0 5902.0 6715.0 8968.0 11181.0 15091.0 17976.0
JTYSPR Yokota AB, Japan 15091.0
MCCSPR McClellan, California 5702.0 5902.0 6715.0 8968.0 11181.0
OFFSPR Offutt AFB, Nebraska 3113.0 5702.0 5902.0 6715.0 8968.0 11181.0 15091.0 17976.0
PLASPR Lajes AB, Azores 5702.0 6715.0 8968.0 11181.0 15091.0
NIPR (Non-Secure Internet Protocol Router) Network Frequencies
(USB/ALE): 3068.0 4745.0 5684.0 8965.0 10600.0 10830.0 11199.0 13242.0 17973.0 20631.0 kHz.
NIPR Gateway/Frequency Matrix
ADWNPR Andrews AFB, Maryland 3068.0 4745.0 5684.0 8965.0 11199.0 13242.0 17973.0 20631.0
CRONPR Croughton AB, United Kingdom 3068.0 4745.0 8965.0 17973.0
HIKNPR Hickam AFB, Hawaii 8965.0
ICZNPR Sigonella NS, Sicily, Italy 4745.0 5684.0 8965.0 13242.0 17973.0 20631.0
JNRNPR Salinas, Puerto Rico 8965.0
MCCNPR McClellan, California 4745.0 5684.0 8965.0 13242.0 17973.0
OFFNPR Offutt AFB, Nebraska 5684.0 8965.0 11199.0 13242.0 17973.0 20631.0