Hello, So basically it has to do with encapsulation. GRE over IPSEC would be encapsulating a GRE packet inside of an IPSEC packet. So your packet would look something like this:
[IPSEC][GRE][IP] With this sort of setup you can basically use more complex features (OSPF, EIGRP, multicast, other dynamic routing -- Plain old IPSEC I believe only supports static routing). In this setup, you have IPSEC on the outside protecting everyting. With IPSEC over GRE you have the opposite. So your packet would look something like this: [GRE][IPSEC][IP] With that kind of setup, you are only securing the payload inside the IPSEC encapsulation (the IP information), and not the header information of the GRE. HTH On Sun, Aug 30, 2009 at 9:33 AM, prakash patel <[email protected]>wrote: > It is how the packe will be formed on What will be desitnation address . > > Please read CCNA-Security notes. > > GRE over IPSEC protects whole IPSEC packet > > > while IPSEC over GRE protects tunnel by providing integrity. > > > > ------------------------------ > Date: Sun, 30 Aug 2009 18:36:14 +0530 > From: [email protected] > To: [email protected] > Subject: [OSL | CCIE_RS] GRE over IPSec <----> IPSec over GRE > > could some one give basic diff between above two terms ? > > -- > Taqdir Singh | Network Engineering | 09911709496 > > Do today what others won't so you can live tomorrow as others can't > > ------------------------------ > Get back to school stuff for them and cashback for you. Try Bing > now.<http://www.bing.com/cashback?form=MSHYCB&publ=WLHMTAG&crea=TEXT_MSHYCB_BackToSchool_Cashback_BTSCashback_1x1> > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > -- Regards, Joe Astorino - CCIE #24347 R&S Technical Instructor - IPexpert, Inc. Cell: +1.586.212.6107 Fax: +1.810.454.0130 Mailto: [email protected]
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