Debug Site to Site VPN
(2013 March 8)
Useful commands for a v9.x VPN debug
Phase 1:
- you want to see MM_ACTIVE in the State
ciscoasa# show crypto isakmp sa
IKEv1 SAs:
Active SA: 1
Rekey SA: 0 (A tunnel will report 1 Active and 1 Rekey SA during rekey)
Total IKE SA: 1
1 IKE Peer: 172.17.1.1
Type : L2L Role : responder
Rekey : no State : MM_ACTIVE
There are no IKEv2 SAs
Phase 2:
- you are looking for non-zero esp sa values as well as non-zero values in the first two pkts lines:
ciscoasa# show crypto ipsec sa peer 172.17.1.1
peer address: 172.17.1.1
Crypto map tag: outside_map, seq num: 10, local addr: 172.16.1.1
access-list asa-router-vpn extended permit ip 10.10.10.0 255.255.255.0
10.20.10.0 255.255.255.0
local ident (addr/mask/prot/port): (10.10.10.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (10.20.10.0/255.255.255.0/0/0)
current_peer: 172.17.1.1
#pkts encaps: 1005, #pkts encrypt: 1005, #pkts digest: 1005
#pkts decaps: 1014, #pkts decrypt: 1014, #pkts verify: 1014
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 1005, #pkts comp failed: 0, #pkts decomp failed: 0
#pre-frag successes: 0, #pre-frag failures: 0, #fragments created: 0
#PMTUs sent: 0, #PMTUs rcvd: 0, #decapsulated frgs needing reassembly: 0
#TFC rcvd: 0, #TFC sent: 0
#Valid ICMP Errors rcvd: 0, #Invalid ICMP Errors rcvd: 0
#send errors: 0, #recv errors: 0
local crypto endpt.: 172.16.1.1/0, remote crypto endpt.: 172.17.1.1/0
path mtu 1500, ipsec overhead 74(44), media mtu 1500
PMTU time remaining (sec): 0, DF policy: copy-df
ICMP error validation: disabled, TFC packets: disabled
current outbound spi: 8A9FE619
current inbound spi : D8639BD0
inbound esp sas:
spi: 0xD8639BD0 (3630406608)
transform: esp-aes esp-sha-hmac no compression
in use settings ={L2L, Tunnel, IKEv1, }
slot: 0, conn_id: 8192, crypto-map: outside_map
sa timing: remaining key lifetime (kB/sec): (3914900/3519)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0xFFFFFFFF 0xFFFFFFFF
outbound esp sas:
spi: 0x8A9FE619 (2325734937)
transform: esp-aes esp-sha-hmac no compression
in use settings ={L2L, Tunnel, IKEv1, }
slot: 0, conn_id: 8192, crypto-map: outside_map
sa timing: remaining key lifetime (kB/sec): (3914901/3519)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0x00000000 0x00000001
ciscoasa#
Useful commands for VPN debug
Phase 1 status:
sha-firewall01-p# show crypto isakmp sa
Active SA: 2
Rekey SA: 0 (A tunnel will report 1 Active and 1 Rekey SA during rekey)
Total IKE SA: 2
1 IKE Peer: 72.xx.xx.xx
Type : L2L Role : initiator
Rekey : no State : MM_ACTIVE
2 IKE Peer: 93.xx.xx.xx
Type : L2L Role : initiator
Rekey : no State : MM_ACTIVE
Phase 2 status:
sha-firewall01-p# show crypto ipsec sa
[[...]]
Forcing A Reconnect
Kill phase 2:
clear crytop ipsec sa peer 1.1.1.1
Kill phase 1:
clear crytop isakmp sa peer 1.1.1.1
Debug logging
Logs to console or ssh session. (Don't know about syslog right now.)
Phase 1:
debug crypto isakmp 127
Phase 2:
debug crypto ipsec 127
For both, increasing to 254 will show you the packets, but you shouldn't need that. Note this will be noisy on systems with more than one VPN.