pciaccio Wed, 06/20/2007 - 04:32

PPTP is a Mocrosoft proprietary security standard and uses TCP 1723.It is supported on most security devices as an option to use. IPSEc is an open standard used by all security vendors and uses TCP ports 50 for ESP and TCP 51 for the AH header for the phases of IPSEC...

Richard Burts Wed, 06/20/2007 - 05:09


One correction: ESP (50) and AH (51) are not TCP ports but are IP protocols. (similar to the way that TCP and UDP are IP protocols) If you wrote an access list and matched on tcp port 50 you would get traffic for the remote mail checking protocol.



carl_townshend Wed, 06/20/2007 - 08:19

so does pptp use ip sec? or is its own security protocol, as ive seen an option on my server for ipsec !!

pciaccio Wed, 06/20/2007 - 09:21

Actually, I learned that PPTP uses the GRE protocol. I am not sure if it uses IPSEC....

Wilson Samuel Wed, 06/20/2007 - 10:35

Hi Carl,

Good question indeed.

Infact, PPTP doesn't user IPSec, however to authenticate it can user PAP (Password Authentication Protocol), SPAP, MS-CHAP (Microsoft Challange Handshake Authentication Protocol) , MS CHAP v2!

And Encryption is an Option over here, the encryption is done using MPPE or Microsoft Point-to-Point Encryption.

Howeve, there is a newer standard which is a mixed version of L2F and PPTP, called L2TP which could be used with IPSec.

You may visit the following URL for details:-


I hope this helps,

Please rate if it helps,

Kind Regards,

Wilson Samuel


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