I am using Windows server 2012 R2 standard and hosted for the Gateway server. I ran IIS crypto as well , but still overall rating as " B " only.
This server supports weak Diffie-Hellman (DH) key exchange parameters. Grade capped to B
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (0x9f) DH 1024 bits FS WEAK
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x9e) DH 1024 bits FS WEAK
Can any one help on this.