What are the four main steps in configuring a GRE tunnel over IPsec on Cisco routers? (Choose Four)
A. Configure a physical interface or create a loopback interface to use as the tunnel endpoint.
B. Create the GRE tunnel interfaces.
C. Add the tunnel interfaces to the routing process so that it exchanages routing updates across that interface.
D. Add the tunnel subnet to the routing process so that it exchanages routing updates across that interface.
E. Add all subnets to the crypto access-list, so that IPsec encrypts the GRE tunnel traffic.
F. Add GRE traffic to the crypto access-list, so that IPsec encrypts the GRE tunnel traffic.
ABCF
We always add interfaice to the routing process.
2 ways define interface:
– from router config – define via net-host/wildcard (its can be 0..0.0.0 wildcard) .
– from interface dirrectly.
why not ABCF?
C vs D… in routing procces we always add interface, not subnet.
2 ways add interface routing process: under interface subcommand, or from routing procees – via network wildcard command, that is define interface or subset of interfaces.