本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。
# 對與 Cisco IOS 客戶閘道裝置的 AWS Site-to-Site VPN 連線進行故障診斷
當您對 Cisco 客戶閘道裝置的連線問題進行故障診斷時，請考量四件事：IKE、IPsec、通道和 BGP。您可依任何順序故障診斷這些區域，但建議您從 IKE 開始 (網路堆疊底部的)，一路向上。
## IKE
使用下列 命令。回應顯示客戶閘道裝置的 IKE 設定正確。
```
router# show crypto isakmp sa
```
```
IPv4 Crypto ISAKMP SA
dst src state conn-id slot status
192.168.37.160 72.21.209.193 QM_IDLE 2001 0 ACTIVE
192.168.37.160 72.21.209.225 QM_IDLE 2002 0 ACTIVE
```
您應該會看到一或多行包含通道中所指定遠端閘道的 `src` 數值。`state` 應為 `QM_IDLE`，而 `status` 應為 `ACTIVE`。缺少項目或任何項目處於其他狀態，都表示 IKE 未正確設定。
如需進一步故障診斷，請執行下列命令來啟用提供診斷資訊的日誌訊息。
```
router# term mon
router# debug crypto isakmp
```
使用下列命令停用除錯。
```
router# no debug crypto isakmp
```
## IPsec
使用下列 命令。回應顯示客戶閘道裝置的 IPsec 設定正確。
```
router# show crypto ipsec sa
```
```
interface: Tunnel1
Crypto map tag: Tunnel1-head-0, local addr 192.168.37.160
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.: 72.21.209.225
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 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 72.21.209.193 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.: 72.21.209.193
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:
```
對於每個通道界面，您應該都會同時看到 `inbound esp sas` 和 `outbound esp sas`。假設列出 SA (例如，`spi: 0xF95D2F3C`)，而且 `Status` 為 `ACTIVE`，則 IPsec 設定正確。
如需進一步故障診斷，請使用下列命令啟用除錯。
```
router# debug crypto ipsec
```
使用下列命令停用除錯。
```
router# no debug crypto ipsec
```
## 通道
首先，請檢查您有沒有必要的防火牆規則。如需詳細資訊，請參閱[AWS Site-to-Site VPN 客戶閘道裝置的防火牆規則](FirewallRules.md)。
如果您的防火牆規則設定正確，則繼續使用下列命令來進行故障診斷。
```
router# show interfaces tun1
```
```
Tunnel1 is up, line protocol is up
Hardware is Tunnel
Internet address is 169.254.255.2/30
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 72.21.209.225
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
```
確定 `line protocol` 已啟動。分別針對通道來源 IP 地址、來源界面和目標，檢查其是否與 IP 地址外客戶閘道裝置、界面和 IP 地址外虛擬私有閘道的通道組態相符。確定 `Tunnel protection via IPSec` 已存在。於這兩個通道界面上執行此命令。若要解決任何問題，請檢閱組態，並檢查與客戶閘道裝置的實體連接。
同時也使用下列命令，將 `169.254.255.1` 換成虛擬私有閘道的內部 IP 地址。
```
router# ping 169.254.255.1 df-bit size 1410
```
```
Type escape sequence to abort.
Sending 5, 1410-byte ICMP Echos to 169.254.255.1, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!
```
您應該會看見五個驚嘆號。
如需進一步故障診斷，請檢閱組態。
## BGP
使用下列 命令。
```
router# show ip bgp summary
```
```
BGP router identifier 192.168.37.160, local AS number 65000
BGP table version is 8, main routing table version 8
2 network entries using 312 bytes of memory
2 path entries using 136 bytes of memory
3/1 BGP path/bestpath attribute entries using 444 bytes of memory
1 BGP AS-PATH entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
Bitfield cache entries: current 1 (at peak 2) using 32 bytes of memory
BGP using 948 total bytes of memory
BGP activity 4/1 prefixes, 4/1 paths, scan interval 15 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
169.254.255.1 4 7224 363 323 8 0 0 00:54:21 1
169.254.255.5 4 7224 364 323 8 0 0 00:00:24 1
```
應會列出兩個鄰近項目。每一個都應該會看到 `State/PfxRcd` 的數值為 `1`。
如果 BGP 對等互連已啟動，請確認您的客戶閘道裝置是否向 VPC 公告預設路由 (0.0.0.0/0)。
```
router# show bgp all neighbors 169.254.255.1 advertised-routes
```
```
For address family: IPv4 Unicast
BGP table version is 3, local router ID is 174.78.144.73
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Originating default network 0.0.0.0
Network Next Hop Metric LocPrf Weight Path
*> 10.120.0.0/16 169.254.255.1 100 0 7224 i
Total number of prefixes 1
```
此外，確定您會從虛擬私有閘道收到對應至您 VPC 的字首。
```
router# show ip route bgp
```
```
10.0.0.0/16 is subnetted, 1 subnets
B 10.255.0.0 [20/0] via 169.254.255.1, 00:00:20
```
如需進一步故障診斷，請檢閱組態。