Generic Routing Encapsulation (GRE)  Enable GRE
 Checksum
 Key
 Sequence Number
Authentication Header (AH)  Enable AH
 HMAC-MD5-96
 HMAC-SHA-1-96
 HMAC-SHA-256-128
 HMAC-SHA-384-192
 HMAC-SHA-512-256
Encapsulating Security Payload (ESP)
 Encryption
 3DES
 AES
 DES
 NULL
 Authentication
 HMAC-MD5-96
 HMAC-SHA-1-96
 HMAC-SHA-256-128
 HMAC-SHA-384-192
 HMAC-SHA-512-256
Encapsulation Parameters
Encapsulation Mode:  Transport   Tunnel
Outer IP Version:  IPv4   IPv6
Inner IP Version:  IPv4   IPv6
Payload Parameters
Payload Size:

Encrypted Packet Layout Calculator

Clear-text packets can either be transported or tunneled through an encryption layer. There are many choices in doing this, and each choice adds a layer to the encrypted packet. Make your choices on the left and see how it affects the encrypted packet design below.