69Chapter 6 VPN configurationChapter contentsIntroduction ..........................................................................................................................................................76Authentication ................................................................................................................................................76Encryption ......................................................................................................................................................76Transport and tunnel modes ...........................................................................................................................77VPN configuration task list ...................................................................................................................................77Creating an IPsec transformation profile .........................................................................................................77Creating an IPsec policy profile .......................................................................................................................78Creating/modifying an outgoing ACL profile for IPsec ...................................................................................80Configuration of an IP interface and the IP router for IPsec ............................................................................81Displaying IPsec configuration information ....................................................................................................81Debugging IPsec .............................................................................................................................................82Sample configurations ...........................................................................................................................................83IPsec tunnel, DES encryption .........................................................................................................................83IPLink configuration .................................................................................................................................83Cisco router configuration .........................................................................................................................84IPsec tunnel, AES encryption at 256 bit key length, AH authentication with HMAC-SHA1-96 ....................84IPLink configuration .................................................................................................................................84Cisco router configuration .........................................................................................................................85IPsec tunnel, 3DES encryption at 192 bit key length, ESP authentication with HMAC-MD5-96 ..................85IPLink configuration .................................................................................................................................85Cisco router configuration .........................................................................................................................85