GRE Flashcards
Supports multiple Layer 3 protocols such as IP, IPX, and Apple Talk?
GRE (Generic Routing Encapsulation)
GRE adds a ____ byte IP header and a ____ GRE header
20
4
What IP protocol defines GRE packets?
47
GRE is _____. It does not by default include any flow control mechanisms.
stateless
What command allows you to create a tunnel interface with a tunnel id of 1?
interface tunnel 1
What command specifies the GRE tunnel mode as the tunnel interface mode in interface tunnel configuration mode?
Note: This is the default tunnel mode on Cisco routers
tunnel mode gre ip
What command specifies the tunnel source IP address in interface tunnel configuration mode
tunnel source [ip address]
What command specifies the tunnel destination IP address in interface tunnel configuration mode?
tunnel destination [ip address]
What command verifies whether a tunnel interface is up or down for tunnel0?
show ip int brief tunnel0
What command verifies the state of tunnel0?
show interface tunnel0
What error could occur due to a misconfiguration that causes the router to try to route to the tunnel destination address by using the tunnel interface itself?
recursive routing
What statement is correct regarding GRE tunnels:
Tunnel interface # is locally significant
Tunnel destination must be IP address or interface #
Tunnel source must be IP address or interface #
Route to tunnel destination must exist on local router
Tunnel interface # is locally significant
Tunnel source must be IP address or interface #
Route to tunnel must exist on local router
What five main components does GRE over IPSec have?
Tunnel interface
Tunnel interface IP address
Tunnel source interface or IP address
Tunnel destination IP address
IPSec policy
Where is the IPSec policy defined?
In a crypto map reference by name in the tunnel configuration
Which IPsec security protocol should be used when confidentiality is required?
A. MD5
B. PSK
C. AH
D. ESP
D. ESP
