Cisco ASA Site-to-Site VPN Dropping
I have three sites, Toronto (1.1.1.1), Mississauga (2.2.2.2) and San Francisco (3.3.3.3). All three sites have ASA 5520. All the sites are connected together with two site-to-site VPN links between each other location.
My issue is that the tunnel between Toronto and San Francisco is very unstable, dropping every 40 min to 60 mins. The tunnel between Toronto and Mississauga (which is configured in the same manner) is fine with no drops.
I also noticed that my pings with drop but the ASA thinks that the tunnel is still up and running.
Here is the configuration of the tunnel.
Toronto (1.1.1.1)
crypto map Outside_map 1 match address Outside_cryptomap
crypto map Outside_map 1 set peer 3.3.3.3
crypto map Outside_map 1 set ikev1 transform-set ESP-AES-256-MD5 ESP-AES-256-SHA
crypto map Outside_map 1 set ikev2 ipsec-proposal AES256
group-policy GroupPolicy_3.3.3.3 internal
group-policy GroupPolicy_3.3.3.3 attributes
vpn-idle-timeout none
vpn-tunnel-protocol ikev1 ikev2
tunnel-group 3.3.3.3 type ipsec-l2l
tunnel-group 3.3.3.3 general-attributes
default-group-policy GroupPolicy_3.3.3.3
tunnel-group 3.3.3.3 ipsec-attributes
ikev1 pre-shared-key *****
isakmp keepalive disable
ikev2 remote-authentication pre-shared-key *****
ikev2 local-authentication pre-shared-key *****
San Francisco (3.3.3.3)
crypto map Outside_map0 2 match address Outside_cryptomap_1
crypto map Outside_map0 2 set peer 1.1.1.1
crypto map Outside_map0 2 set ikev1 transform-set ESP-AES-256-MD5 ESP-AES-256-SHA
crypto map Outside_map0 2 set ikev2 ipsec-proposal AES256
group-policy GroupPolicy_1.1.1.1 internal
group-policy GroupPolicy_1.1.1.1 attributes
vpn-idle-timeout none
vpn-tunnel-protocol ikev1 ikev2
tunnel-group 1.1.1.1 type ipsec-l2l
tunnel-group 1.1.1.1 general-attributes
default-group-policy GroupPolicy_1.1.1.1
tunnel-group 1.1.1.1 ipsec-attributes
ikev1 pre-shared-key *****
isakmp keepalive disable
ikev2 remote-authentication pre-shared-key *****
ikev2 local-authentication pre-shared-key *****
I'm at a loss. Any ideas?
Update:
# show crypto isakmp sa
IKEv1 SAs:
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: 3.3.3.3
Type : L2L Role : initiator
Rekey : no State : MM_ACTIVE
2 IKE Peer: 2.2.2.2
Type : L2L Role : responder
Rekey : no State : MM_ACTIVE
There are no IKEv2 SAs
# show crypto ipsec sa
interface: Outside
Crypto map tag: External_map, seq num: 3, local addr: 1.1.1.1
access-list Outside_cryptomap_1 extended permit ip 10.0.0.0 255.255.0.0 10.99.0.0 255.255.255.0
local ident (addr/mask/prot/port): (10.0.0.0/255.255.0.0/0/0)
remote ident (addr/mask/prot/port): (10.99.0.0/255.255.255.0/0/0)
current_peer: 74.200.4.148
#pkts encaps: 30948, #pkts encrypt: 30948, #pkts digest: 30948
#pkts decaps: 28516, #pkts decrypt: 28516, #pkts verify: 28516
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 30948, #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
#send errors: 0, #recv errors: 0
local crypto endpt.: 1.1.1.1/0, remote crypto endpt.: 2.2.2.2/0
path mtu 1500, ipsec overhead 74, media mtu 1500
current outbound spi: EFADD3D6
current inbound spi : 756AB014
inbound esp sas:
spi: 0x756AB014 (1969926164)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (4372005/17024)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0xFFFFFFFF 0xFFFFFFFF
outbound esp sas:
spi: 0xEFADD3D6 (4021146582)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (4369303/17024)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0x00000000 0x00000001
Crypto map tag: External_map, seq num: 3, local addr: 1.1.1.1
access-list Outside_cryptomap_1 extended permit ip 10.0.0.0 255.255.0.0 10.100.0.0 255.255.0.0
local ident (addr/mask/prot/port): (10.0.0.0/255.255.0.0/0/0)
remote ident (addr/mask/prot/port): (10.100.0.0/255.255.0.0/0/0)
current_peer: 2.2.2.2
#pkts encaps: 18777146, #pkts encrypt: 18777329, #pkts digest: 18777329
#pkts decaps: 23208489, #pkts decrypt: 23208489, #pkts verify: 23208489
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 18777328, #pkts comp failed: 0, #pkts decomp failed: 0
#pre-frag successes: 1, #pre-frag failures: 0, #fragments created: 2
#PMTUs sent: 0, #PMTUs rcvd: 0, #decapsulated frgs needing reassembly: 0
#send errors: 0, #recv errors: 0
local crypto endpt.: 1.1.1.1/0, remote crypto endpt.: 2.2.2.2/0
path mtu 1500, ipsec overhead 74, media mtu 1500
current outbound spi: D2002A5B
current inbound spi : 2E1F7B20
inbound esp sas:
spi: 0x2E1F7B20 (773815072)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (3224936/17000)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0xFFFFFFFF 0xFFFFFFFF
outbound esp sas:
spi: 0xD2002A5B (3523226203)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (2120164/17000)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0x00000000 0x00000001
Crypto map tag: External_map, seq num: 3, local addr: 1.1.1.1
access-list Outside_cryptomap_1 extended permit ip 10.0.0.0 255.255.0.0 10.110.0.0 255.255.0.0
local ident (addr/mask/prot/port): (10.0.0.0/255.255.0.0/0/0)
remote ident (addr/mask/prot/port): (10.110.0.0/255.255.0.0/0/0)
current_peer: 2.2.2.2
#pkts encaps: 1289226, #pkts encrypt: 1289226, #pkts digest: 1289226
#pkts decaps: 1594987, #pkts decrypt: 1594987, #pkts verify: 1594987
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 1289226, #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: 27
#send errors: 0, #recv errors: 0
local crypto endpt.: 1.1.1.1/0, remote crypto endpt.: 2.2.2.2/0
path mtu 1500, ipsec overhead 74, media mtu 1500
current outbound spi: 45B5CECD
current inbound spi : 862EB1DB
inbound esp sas:
spi: 0x862EB1DB (2251207131)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (4318958/16999)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0xFFFFFFFF 0xFFFFFFFF
outbound esp sas:
spi: 0x45B5CECD (1169542861)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1015808, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (4360717/16999)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0x00000000 0x00000001
Crypto map tag: External_map, seq num: 1, local addr: 1.1.1.1
access-list Outside_cryptomap extended permit ip 10.0.0.0 255.255.0.0 10.10.0.0 255.255.0.0
local ident (addr/mask/prot/port): (10.0.0.0/255.255.0.0/0/0)
remote ident (addr/mask/prot/port): (10.10.0.0/255.255.0.0/0/0)
current_peer: 3.3.3.3
#pkts encaps: 3444336, #pkts encrypt: 3444336, #pkts digest: 3444336
#pkts decaps: 1756137, #pkts decrypt: 1756137, #pkts verify: 1756137
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 3444336, #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
#send errors: 0, #recv errors: 0
local crypto endpt.: 1.1.1.1/0, remote crypto endpt.: 3.3.3.3/0
path mtu 1500, ipsec overhead 74, media mtu 1500
current outbound spi: 6B0981E6
current inbound spi : 2F85EB3C
inbound esp sas:
spi: 0x2F85EB3C (797305660)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1245184, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (3944948/12647)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0xFFFFFFFF 0xFFFFFFFF
outbound esp sas:
spi: 0x6B0981E6 (1795785190)
transform: esp-aes-256 esp-md5-hmac no compression
in use settings ={L2L, Tunnel, PFS Group 2, }
slot: 0, conn_id: 1245184, crypto-map: External_map
sa timing: remaining key lifetime (kB/sec): (364451/12647)
IV size: 16 bytes
replay detection support: Y
Anti replay bitmap:
0x00000000 0x00000001
ScottAdair1 Answer
I think it might be the keepalive being disabled, if there is not traffic or traffic it routing another way it may be causing the tunnel to drop do to inactivity. Try dropping the tunnel (clear isakmp sa $PEERIP) on the destination then running debug on the source and see if it is trying to re-establish the connection. http://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike-protocols/5409-ipsec-debug-00.html#crypto_isakmp
answered on Server Fault Jun 11, 2015 by 
chrisw9808
chrisw9808User contributions licensed under CC BY-SA 3.0