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# 使用瞻博网络 ScreenOS 客户网关设备进行 AWS Site-to-Site VPN 连接故障排除
对基于瞻博网络 ScreenOS 的客户网关设备的连接进行故障排除时，请考虑四件事：IKE IPsec、隧道和 BGP。您可以按任何次序对这些方面进行故障排除，不过建议您从 IKE 开始（位于网络堆栈的底部）并依次向上排除。
## IKE 和 IPsec
使用以下命令。响应显示带正确配置的 IKE 的客户网关设备。
```
ssg5-serial-> get sa
```
```
total configured sa: 2
HEX ID Gateway Port Algorithm SPI Life:sec kb Sta PID vsys
00000002< 72.21.209.225 500 esp:a128/sha1 80041ca4 3385 unlim A/- -1 0
00000002> 72.21.209.225 500 esp:a128/sha1 8cdd274a 3385 unlim A/- -1 0
00000001< 72.21.209.193 500 esp:a128/sha1 ecf0bec7 3580 unlim A/- -1 0
00000001> 72.21.209.193 500 esp:a128/sha1 14bf7894 3580 unlim A/- -1 0
```
您应该可以看到包含隧道中所指定远程网关的远程地址的一行或多行。`Sta` 值应为 `A/-`，而 `SPI` 应为 `00000000` 以外的十六进制数。处于其他状态的项表示 IKE 未正确配置。
如需进一步进行问题排查，请启用 IKE 跟踪选项（如示例配置文件中所推荐）。
## 隧道
首先，请反复检查必要的防火墙已布置到位。有关规则列表，请参阅[AWS Site-to-Site VPN 客户网关设备的防火墙规则](FirewallRules.md)。
如果您的防火墙规则设置正确，则请使用下面的命令继续排除故障。
```
ssg5-serial-> get interface tunnel.1
```
```
Interface tunnel.1:
description tunnel.1
number 20, if_info 1768, if_index 1, mode route
link ready
vsys Root, zone Trust, vr trust-vr
admin mtu 1500, operating mtu 1500, default mtu 1500
*ip 169.254.255.2/30
*manage ip 169.254.255.2
route-deny disable
bound vpn:
IPSEC-1
Next-Hop Tunnel Binding table
Flag Status Next-Hop(IP) tunnel-id VPN
pmtu-v4 disabled
ping disabled, telnet disabled, SSH disabled, SNMP disabled
web disabled, ident-reset disabled, SSL disabled
OSPF disabled BGP enabled RIP disabled RIPng disabled mtrace disabled
PIM: not configured IGMP not configured
NHRP disabled
bandwidth: physical 0kbps, configured egress [gbw 0kbps mbw 0kbps]
configured ingress mbw 0kbps, current bw 0kbps
total allocated gbw 0kbps
```
确保您可以看到 `link:ready`，并且 `IP` 地址匹配客户网关设备隧道的内部地址。
下一步，请使用下面的命令，将 `169.254.255.1` 替换为您的虚拟专用网关的内部 IP 地址。您得到的结果看上去应该如此处所示。
```
ssg5-serial-> ping 169.254.255.1
```
```
Type escape sequence to abort
Sending 5, 100-byte ICMP Echos to 169.254.255.1, timeout is 1 seconds
!!!!!
Success Rate is 100 percent (5/5), round-trip time min/avg/max=32/32/33 ms
```
如需进一步排查问题，请核查配置。
## BGP
运行如下命令。
```
ssg5-serial-> get vrouter trust-vr protocol bgp neighbor
```
```
Peer AS Remote IP Local IP Wt Status State ConnID Up/Down
--------------------------------------------------------------------------------
7224 169.254.255.1 169.254.255.2 100 Enabled ESTABLISH 10 00:01:01
7224 169.254.255.5 169.254.255.6 100 Enabled ESTABLISH 11 00:00:59
```
两个 BGP 对等体的状态均为 `ESTABLISH`，这表示与虚拟私有网关的 BGP 连接是活动的。
如需进一步排查问题，请使用下面的命令，将 `169.254.255.1` 替换为您的虚拟专用网关的内部 IP 地址。
```
ssg5-serial-> get vr trust-vr prot bgp neigh 169.254.255.1
```
```
peer: 169.254.255.1, remote AS: 7224, admin status: enable
type: EBGP, multihop: 0(disable), MED: node default(0)
connection state: ESTABLISH, connection id: 18 retry interval: node default(120s), cur retry time 15s
configured hold time: node default(90s), configured keepalive: node default(30s)
configured adv-interval: default(30s)
designated local IP: n/a
local IP address/port: 169.254.255.2/13946, remote IP address/port: 169.254.255.1/179
router ID of peer: 169.254.255.1, remote AS: 7224
negotiated hold time: 30s, negotiated keepalive interval: 10s
route map in name: , route map out name:
weight: 100 (default)
self as next hop: disable
send default route to peer: disable
ignore default route from peer: disable
send community path attribute: no
reflector client: no
Neighbor Capabilities:
Route refresh: advertised and received
Address family IPv4 Unicast: advertised and received
force reconnect is disable
total messages to peer: 106, from peer: 106
update messages to peer: 6, from peer: 4
Tx queue length 0, Tx queue HWM: 1
route-refresh messages to peer: 0, from peer: 0
last reset 00:05:33 ago, due to BGP send Notification(Hold Timer Expired)(code 4 : subcode 0)
number of total successful connections: 4
connected: 2 minutes 6 seconds
Elapsed time since last update: 2 minutes 6 seconds
```
如果 BGP 对等体已运行，请验证您的客户网关设备正在向 VPC 通告默认路由 (0.0.0.0/0)。该命令适用于 ScreenOS 6.2.0 和更高版本。
```
ssg5-serial-> get vr trust-vr protocol bgp rib neighbor 169.254.255.1 advertised
```
```
i: IBGP route, e: EBGP route, >: best route, *: valid route
Prefix Nexthop Wt Pref Med Orig AS-Path
--------------------------------------------------------------------------------------
>i 0.0.0.0/0 0.0.0.0 32768 100 0 IGP
Total IPv4 routes advertised: 1
```
另外，确保您正在从虚拟私有网关接收对应于您的 VPC 的前缀。该命令适用于 ScreenOS 6.2.0 和更高版本。
```
ssg5-serial-> get vr trust-vr protocol bgp rib neighbor 169.254.255.1 received
```
```
i: IBGP route, e: EBGP route, >: best route, *: valid route
Prefix Nexthop Wt Pref Med Orig AS-Path
--------------------------------------------------------------------------------------
>e* 10.0.0.0/16 169.254.255.1 100 100 100 IGP 7224
Total IPv4 routes received: 1
```