# Troubleshoot AWS Site-to-Site VPN connectivity with a Cisco IOS customer gateway device without Border Gateway Protocol
When you troubleshoot the connectivity of a Cisco customer gateway device, consider three things: IKE, IPsec, and tunnel. You can troubleshoot these areas in any order, but we recommend that you start with IKE (at the bottom of the network stack) and move up.
## IKE
Use the following command. The response shows a customer gateway device with IKE configured correctly.
```
router# show crypto isakmp sa
```
```
IPv4 Crypto ISAKMP SA
dst src state conn-id slot status
174.78.144.73 205.251.233.121 QM_IDLE 2001 0 ACTIVE
174.78.144.73 205.251.233.122 QM_IDLE 2002 0 ACTIVE
```
You should see one or more lines containing an `src` value for the remote gateway that is specified in the tunnels. The `state` should be `QM_IDLE` and `status` should be `ACTIVE`. The absence of an entry, or any entry in another state, indicates that IKE is not configured properly.
For further troubleshooting, run the following commands to enable log messages that provide diagnostic information.
```
router# term mon
router# debug crypto isakmp
```
To disable debugging, use the following command.
```
router# no debug crypto isakmp
```
## IPsec
Use the following command. The response shows a customer gateway device with IPsec configured correctly.
```
router# show crypto ipsec sa
```
```
interface: Tunnel1
Crypto map tag: Tunnel1-head-0, local addr 174.78.144.73
protected vrf: (none)
local ident (addr/mask/prot/port): (0.0.0.0/0.0.0.0/0/0)
remote ident (addr/mask/prot/port): (0.0.0.0/0.0.0.0/0/0)
current_peer 72.21.209.225 port 500
PERMIT, flags={origin_is_acl,}
#pkts encaps: 149, #pkts encrypt: 149, #pkts digest: 149
#pkts decaps: 146, #pkts decrypt: 146, #pkts verify: 146
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0
#pkts not decompressed: 0, #pkts decompress failed: 0
#send errors 0, #recv errors 0
local crypto endpt.: 174.78.144.73, remote crypto endpt.:205.251.233.121
path mtu 1500, ip mtu 1500, ip mtu idb FastEthernet0
current outbound spi: 0xB8357C22(3090512930)
inbound esp sas:
spi: 0x6ADB173(112046451)
transform: esp-aes esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 1, flow_id: Motorola SEC 2.0:1, crypto map: Tunnel1-head-0
sa timing: remaining key lifetime (k/sec): (4467148/3189)
IV size: 16 bytes
replay detection support: Y replay window size: 128
Status: ACTIVE
inbound ah sas:
inbound pcp sas:
outbound esp sas:
spi: 0xB8357C22(3090512930)
transform: esp-aes esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 2, flow_id: Motorola SEC 2.0:2, crypto map: Tunnel1-head-0
sa timing: remaining key lifetime (k/sec): (4467148/3189)
IV size: 16 bytes
replay detection support: Y replay window size: 128
Status: ACTIVE
outbound ah sas:
outbound pcp sas:
interface: Tunnel2
Crypto map tag: Tunnel2-head-0, local addr 205.251.233.122
protected vrf: (none)
local ident (addr/mask/prot/port): (0.0.0.0/0.0.0.0/0/0)
remote ident (addr/mask/prot/port): (0.0.0.0/0.0.0.0/0/0)
current_peer 72.21.209.193 port 500
PERMIT, flags={origin_is_acl,}
#pkts encaps: 26, #pkts encrypt: 26, #pkts digest: 26
#pkts decaps: 24, #pkts decrypt: 24, #pkts verify: 24
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0
#pkts not decompressed: 0, #pkts decompress failed: 0
#send errors 0, #recv errors 0
local crypto endpt.: 174.78.144.73, remote crypto endpt.:205.251.233.122
path mtu 1500, ip mtu 1500, ip mtu idb FastEthernet0
current outbound spi: 0xF59A3FF6(4120526838)
inbound esp sas:
spi: 0xB6720137(3060924727)
transform: esp-aes esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 3, flow_id: Motorola SEC 2.0:3, crypto map: Tunnel2-head-0
sa timing: remaining key lifetime (k/sec): (4387273/3492)
IV size: 16 bytes
replay detection support: Y replay window size: 128
Status: ACTIVE
inbound ah sas:
inbound pcp sas:
outbound esp sas:
spi: 0xF59A3FF6(4120526838)
transform: esp-aes esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 4, flow_id: Motorola SEC 2.0:4, crypto map: Tunnel2-head-0
sa timing: remaining key lifetime (k/sec): (4387273/3492)
IV size: 16 bytes
replay detection support: Y replay window size: 128
Status: ACTIVE
outbound ah sas:
outbound pcp sas:
```
For each tunnel interface, you should see both an inbound `esp sas` and outbound `esp sas`. This assumes that an SA is listed (for example, `spi: 0x48B456A6`), that the status is `ACTIVE`, and that IPsec is configured correctly.
For further troubleshooting, use the following command to enable debugging.
```
router# debug crypto ipsec
```
To disable debugging, use the following command.
```
router# no debug crypto ipsec
```
## Tunnel
First, check that you have the necessary firewall rules in place. For more information, see [Firewall rules for an AWS Site-to-Site VPN customer gateway device](FirewallRules.md).
If your firewall rules are set up correctly, then continue troubleshooting with the following command.
```
router# show interfaces tun1
```
```
Tunnel1 is up, line protocol is up
Hardware is Tunnel
Internet address is 169.254.249.18/30
MTU 17867 bytes, BW 100 Kbit/sec, DLY 50000 usec,
reliability 255/255, txload 2/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 174.78.144.73, destination 205.251.233.121
Tunnel protocol/transport IPSEC/IP
Tunnel TTL 255
Tunnel transport MTU 1427 bytes
Tunnel transmit bandwidth 8000 (kbps)
Tunnel receive bandwidth 8000 (kbps)
Tunnel protection via IPSec (profile "ipsec-vpn-92df3bfb-0")
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/0 (size/max)
5 minute input rate 0 bits/sec, 1 packets/sec
5 minute output rate 1000 bits/sec, 1 packets/sec
407 packets input, 30010 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
```
Make sure that the line protocol is up. Check that the tunnel source IP address, source interface, and destination respectively match the tunnel configuration for the customer gateway device outside IP address, interface, and virtual private gateway outside IP address. Make sure that `Tunnel protection through IPSec` is present. Run the command on both tunnel interfaces. To resolve any problems, review the configuration and check the physical connections to your customer gateway device.
You can also use the following command, replacing `169.254.249.18` with the inside IP address of your virtual private gateway.
```
router# ping 169.254.249.18 df-bit size 1410
```
```
Type escape sequence to abort.
Sending 5, 1410-byte ICMP Echos to 169.254.249.18, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!
```
You should see five exclamation points.
### Routing
To see your static route table, use the following command.
```
router# sh ip route static
```
```
1.0.0.0/8 is variably subnetted
S 10.0.0.0/16 is directly connected, Tunnel1
is directly connected, Tunnel2
```
You should see that the static route for the VPC CIDR through both tunnels exists. If it does not exist, add the static routes as follows.
```
router# ip route 10.0.0.0 255.255.0.0 Tunnel1 track 100
router# ip route 10.0.0.0 255.255.0.0 Tunnel2 track 200
```
### Checking the SLA monitor
```
router# show ip sla statistics 100
```
```
IPSLAs Latest Operation Statistics
IPSLA operation id: 100
Latest RTT: 128 milliseconds
Latest operation start time: *18:08:02.155 UTC Wed Jul 15 2012
Latest operation return code: OK
Number of successes: 3
Number of failures: 0
Operation time to live: Forever
```
```
router# show ip sla statistics 200
```
```
IPSLAs Latest Operation Statistics
IPSLA operation id: 200
Latest RTT: 128 milliseconds
Latest operation start time: *18:08:02.155 UTC Wed Jul 15 2012
Latest operation return code: OK
Number of successes: 3
Number of failures: 0
Operation time to live: Forever
```
The value for `Number of successes` indicates whether the SLA monitor has been set up successfully.
For further troubleshooting, review the configuration.