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GRE over IPSec

Category:Cisco Systems -> Security

In GRE over IPSec scenario, the crypto map is applied to Physical Interface.

GRE over IPsec then the order is GRE first, IPsec second. The order will be:

1.) Original header | Payload ! before GRE

2.) Outer header | GRE | Original header | Payload ! after GRE

3.) Outer header | ESP | Encrypt ( GRE | Original header | Payload ) ! after IPsec transport mode

So all interesting traffic plus GRE’s traffic both are encrypted.

Also see IPSec over GRE

By privilege15