Which command is used to verify that a VPN connection is established between two
endpoints and that the connection is passing?
A.
Firewall#sh crypto ipsec sa
B.
Firewall#sh crypto isakmp sa
C.
Firewall#debug crypto isakmp
D.
Firewall#sh crypto session
show crypto ipsec sa
This command shows IPsec SAs built between peers. The encrypted tunnel is built between 12.1.1.1 and 12.1.1.2 for traffic that goes between networks 20.1.1.0 and 10.1.1.0. You can see the two Encapsulating Security Payload (ESP) SAs built inbound and outbound. Authentication Header (AH) is not used since there are no AH SAs.
This output shows an example of the show crypto ipsec sa command.
interface: FastEthernet0
Crypto map tag: test, local addr. 12.1.1.1
local ident (addr/mask/prot/port): (20.1.1.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (10.1.1.0/255.255.255.0/0/0)
current_peer: 12.1.1.2
PERMIT, flags={origin_is_acl,}
#pkts encaps: 7767918, #pkts encrypt: 7767918, #pkts digest 7767918
#pkts decaps: 7760382, #pkts decrypt: 7760382, #pkts verify 7760382
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0,
#pkts decompress failed: 0, #send errors 1, #recv errors 0
local crypto endpt.: 12.1.1.1, remote crypto endpt.: 12.1.1.2
path mtu 1500, media mtu 1500
current outbound spi: 3D3
inbound esp sas:
spi: 0x136A010F(325714191)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 3442, flow_id: 1443, crypto map: test
sa timing: remaining key lifetime (k/sec): (4608000/52)
IV size: 8 bytes
replay detection support: Y
inbound ah sas:
inbound pcp sas:
inbound pcp sas:
outbound esp sas:
spi: 0x3D3(979)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 3443, flow_id: 1444, crypto map: test
sa timing: remaining key lifetime (k/sec): (4608000/52)
IV size: 8 bytes
replay detection support: Y
outbound ah sas:
outbound pcp sas:
https://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike-protocols/5409-ipsec-debug-00.html