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 Juniper JunOS 客戶閘道裝置的 AWS Site-to-Site VPN 連線進行故障診斷
當您對 Juniper 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。
```
user@router> show security ike security-associations
```
```
Index Remote Address State Initiator cookie Responder cookie Mode
4 72.21.209.225 UP c4cd953602568b74 0d6d194993328b02 Main
3 72.21.209.193 UP b8c8fb7dc68d9173 ca7cb0abaedeb4bb Main
```
您應該會看到一或多行包含通道中所指定的遠端閘道遠端地址。`State` 應為 `UP`。缺少項目或任何項目處於其他狀態 (例如 `DOWN`)，都表示 IKE 未正確設定。
如需進一步故障診斷，請如範例組態檔案中所建議，啟用 IKE 追蹤選項。然後執行下列命令，在螢幕中顯示各種除錯訊息。
```
user@router> monitor start kmd
```
從外部主機，您可以使用下列命令擷取整份日誌檔案。
```
scp username@router.hostname:/var/log/kmd
```
## IPsec
使用下列 命令。回應顯示客戶閘道裝置的 IPsec 設定正確。
```
user@router> show security ipsec security-associations
```
```
Total active tunnels: 2
ID Gateway Port Algorithm SPI Life:sec/kb Mon vsys
<131073 72.21.209.225 500 ESP:aes-128/sha1 df27aae4 326/ unlim - 0
>131073 72.21.209.225 500 ESP:aes-128/sha1 5de29aa1 326/ unlim - 0
<131074 72.21.209.193 500 ESP:aes-128/sha1 dd16c453 300/ unlim - 0
>131074 72.21.209.193 500 ESP:aes-128/sha1 c1e0eb29 300/ unlim - 0
```
特別是，每個閘道地址 (對應至遠端閘道) 至少應該看到兩行。每行開頭的插入號 (< >) 指出特定項目的流量方向。在輸出中，傳入流量 (「<」，從虛擬私有閘道到此客戶閘道裝置的流量) 和傳出流量 (「>」) 各有不同的行。
如需進一步故障診斷，請啟用 IKE 追蹤選項 (詳細資訊請參閱上一節 IKE 內容)。
## 通道
首先，請再次檢查您有沒有必要的防火牆規則。如需規則清單，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。
```
user@router> show interfaces st0.1
```
```
Logical interface st0.1 (Index 70) (SNMP ifIndex 126)
Flags: Point-To-Point SNMP-Traps Encapsulation: Secure-Tunnel
Input packets : 8719
Output packets: 41841
Security: Zone: Trust
Allowed host-inbound traffic : bgp ping ssh traceroute
Protocol inet, MTU: 9192
Flags: None
Addresses, Flags: Is-Preferred Is-Primary
Destination: 169.254.255.0/30, Local: 169.254.255.2
```
確定 `Security: Zone` 正確，而且 `Local` 地址符合客戶閘道裝置通道內部地址。
接著，使用下列命令，以您虛擬私有閘道的內部 IP 地址取代 `169.254.255.1`。您的結果看起來應該類似此處顯示的回應。
```
user@router> ping 169.254.255.1 size 1382 do-not-fragment
```
```
PING 169.254.255.1 (169.254.255.1): 1410 data bytes
64 bytes from 169.254.255.1: icmp_seq=0 ttl=64 time=71.080 ms
64 bytes from 169.254.255.1: icmp_seq=1 ttl=64 time=70.585 ms
```
如需進一步故障診斷，請檢閱組態。
## BGP
執行下列命令。
```
user@router> show bgp summary
```
```
Groups: 1 Peers: 2 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0 2 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
169.254.255.1 7224 9 10 0 0 1:00 1/1/1/0 0/0/0/0
169.254.255.5 7224 8 9 0 0 56 0/1/1/0 0/0/0/0
```
如需進一步故障診斷，請使用下列命令，以您虛擬私有閘道的內部 IP 地址取代 `169.254.255.1`。
```
user@router> show bgp neighbor 169.254.255.1
```
```
Peer: 169.254.255.1+179 AS 7224 Local: 169.254.255.2+57175 AS 65000
Type: External State: Established Flags:
Last State: OpenConfirm Last Event: RecvKeepAlive
Last Error: None
Export: [ EXPORT-DEFAULT ]
Options:
Holdtime: 30 Preference: 170 Local AS: 65000 Local System AS: 0
Number of flaps: 0
Peer ID: 169.254.255.1 Local ID: 10.50.0.10 Active Holdtime: 30
Keepalive Interval: 10 Peer index: 0
BFD: disabled, down
Local Interface: st0.1
NLRI for restart configured on peer: inet-unicast
NLRI advertised by peer: inet-unicast
NLRI for this session: inet-unicast
Peer supports Refresh capability (2)
Restart time configured on the peer: 120
Stale routes from peer are kept for: 300
Restart time requested by this peer: 120
NLRI that peer supports restart for: inet-unicast
NLRI that restart is negotiated for: inet-unicast
NLRI of received end-of-rib markers: inet-unicast
NLRI of all end-of-rib markers sent: inet-unicast
Peer supports 4 byte AS extension (peer-as 7224)
Table inet.0 Bit: 10000
RIB State: BGP restart is complete
Send state: in sync
Active prefixes: 1
Received prefixes: 1
Accepted prefixes: 1
Suppressed due to damping: 0
Advertised prefixes: 1
Last traffic (seconds): Received 4 Sent 8 Checked 4
Input messages: Total 24 Updates 2 Refreshes 0 Octets 505
Output messages: Total 26 Updates 1 Refreshes 0 Octets 582
Output Queue[0]: 0
```
您應該會在此看到每個列出的 `Received prefixes` 與 `Advertised prefixes` 皆為 1。這應屬於 `Table inet.0` 區段。
如果 `State` 不是 `Established`，請檢查 `Last State` 和 `Last Error` 以取得所需詳細資訊來更正問題。
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)。
```
user@router> show route advertising-protocol bgp 169.254.255.1
```
```
inet.0: 10 destinations, 11 routes (10 active, 0 holddown, 0 hidden)
Prefix Nexthop MED Lclpref AS path
* 0.0.0.0/0 Self I
```
此外，確定您會從虛擬私有閘道收到對應至您 VPC 的字首。
```
user@router> show route receive-protocol bgp 169.254.255.1
```
```
inet.0: 10 destinations, 11 routes (10 active, 0 holddown, 0 hidden)
Prefix Nexthop MED Lclpref AS path
* 10.110.0.0/16 169.254.255.1 100 7224 I
```