in tunneling concept in general we have concepts of
carrier , passenger , transport protocol
in case we are using
GRE over IPSec
here GRE should be passenger and IPsec carrier
but in which case IPSec becomes as a Transport ?
in case of underlay protocol(infrastructure protocol) is IPSec so it can be transport
but mostly we have IP Protocol as a Transport
my query is how possible IPSec is used as a Transport?
in other reference i see :
Generally, a logical interface that provides a way to encapsulate passesnger packets inside a transport protocol
but where we use term of carrier protocol
here is the detailed good explanation in the cisco document for reference :
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Hello and thanks for your reply , Yes i see that link and one time i read it.
My Question is in my example GRE over IPSec
if IPSec is transport
GRE is carrier or passenger
and what will that traffic which is encapsulated by GRE !
but generaly tunnel related discussion X over Y means X is passenger and Y is Carrier
From my perspective and my understanding Transport means that protocol which is used to build network infrastructure, i know IP Security is Layer 3 protocol for encryption and also authentication of IP Packet being used !!!
but can purely uses IPsec for building Network infrastructure ....
if NO and from my side i also say NO
if IPSec is transport
GRE should be carrier in this case
because before configuring we can not figure it out what will be our traffic ?
and maybe i am confused with definition of Transport protocol in tunneling
maybe i should be revised
one other idea is we take IPSec as a protocol which encrypting GRE packet and GRE also encapsulated our Data(pasenger protocol in it)
it is Transport for GRE not that things i mentioned before !
but still am i right IPsec ia not in format of network infrastructure protocol and is a protocol for carrying GRE ....
did my previous analysis was correct?
IPSec is transport the Carrier protocol (we can take this one idea)
but still we have like Layer 3 protocols is used for infrastructure (Routing ability)
mostly transport means (as i've understood) ability to gives a routing ;
IPsec although is a Layer 3 (in some reference is mentioned something else)
but how can is being used as a Transport individually
or maybe my description about Transport not correct !
transport for carrier
transport routing infrastructure