安全连接网关虚拟版本（虚拟设备/SCG-VE）：无法注册安全连接网关

即使本地系统可以通过端口 443 和 8443 连接到 Dell Enterprise 服务器，注册安全连接网关也会失败并显示以下错误。

We cannot connect to the Dell backend. Please check and verify your network configuration, ports 8443 and 443 are required and must be open to esrs3-core.emc.com,esrs3-coredr.emc.com.

connectivityreport.log：

2023-02-12 07:12:41,863 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 8443 , IOException ConnectTimeoutException
2023-02-12 07:12:41,863 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 8443 , Exception - Connect to esrs3-core.emc.com:8443 [esrs3-core.emc.com/128.221.236.246] failed: Read timed out
2023-02-12 07:12:41,863 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] connStatus after skipProxy false
2023-02-12 07:12:41,863 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:41,863 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy is null so skipProxy()
2023-02-12 07:12:41,872 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 8443 , IOException ConnectTimeoutException
2023-02-12 07:12:41,872 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 8443 , Exception - Connect to esrs3-coredr.emc.com:8443 [esrs3-coredr.emc.com/168.159.224.236] failed: Read timed out
2023-02-12 07:12:41,872 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] connStatus after skipProxy false
2023-02-12 07:12:41,872 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:41,872 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy is null so skipProxy()
2023-02-12 07:12:52,068 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 8443 , IOException ConnectTimeoutException
2023-02-12 07:12:52,069 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 8443 , Exception - Connect to esrs3-core.emc.com:8443 [esrs3-core.emc.com/128.221.236.246] failed: Read timed out
2023-02-12 07:12:52,069 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] connStatus after skipProxy false
2023-02-12 07:12:52,069 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Call populateConnectivityBean: host esrs3-core.emc.com port: 8443
2023-02-12 07:12:52,069 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:52,069 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy is null so skipProxy()
2023-02-12 07:12:52,087 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 8443 , IOException ConnectTimeoutException
2023-02-12 07:12:52,088 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 8443 , Exception - Connect to esrs3-coredr.emc.com:8443 [esrs3-coredr.emc.com/168.159.224.236] failed: Read timed out
2023-02-12 07:12:52,088 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] connStatus after skipProxy false
2023-02-12 07:12:52,088 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Call populateConnectivityBean: host esrs3-coredr.emc.com port: 8443
2023-02-12 07:12:52,088 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:52,088 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy is null so skipProxy()
2023-02-12 07:12:54,485 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , IOException SSLHandshakeException
2023-02-12 07:12:54,485 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , Exception - Received fatal alert: handshake_failure
2023-02-12 07:12:54,485 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , SSLException or SSLHandshakeException. Consider this as success as just we are checking connectivity to backend core enterprise server.
2023-02-12 07:12:54,485 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] connStatus after skipProxy true
2023-02-12 07:12:54,485 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ]  avgCount: 1 timeTaken: 2397 host: esrs3-coredr.emc.com 
2023-02-12 07:12:54,485 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:54,486 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Proxy is null so skipProxy()
2023-02-12 07:12:54,503 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , IOException SSLHandshakeException
2023-02-12 07:12:54,503 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , Exception - Received fatal alert: handshake_failure
2023-02-12 07:12:54,503 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , SSLException or SSLHandshakeException. Consider this as success as just we are checking connectivity to backend core enterprise server.
2023-02-12 07:12:54,503 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] connStatus after skipProxy true
2023-02-12 07:12:54,503 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ]  avgCount: 1 timeTaken: 2434 host: esrs3-core.emc.com 
2023-02-12 07:12:54,503 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy not enabled, try bypass proxy 
2023-02-12 07:12:54,503 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-1, , ] Proxy is null so skipProxy()
2023-02-12 07:12:56,838 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , IOException SSLHandshakeException
2023-02-12 07:12:56,838 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , Exception - Received fatal alert: handshake_failure
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Host: esrs3-coredr.emc.com Port: 443 , SSLException or SSLHandshakeException. Consider this as success as just we are checking connectivity to backend core enterprise server.
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] connStatus after skipProxy true
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ]  avgCount: 2 timeTaken: 4750 host: esrs3-coredr.emc.com 
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Call populateConnectivityBean: host esrs3-coredr.emc.com port: 443
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] Time taken: 4750
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-2, , ] avgPingTime: 2375.0
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] Latch count is   1
2023-02-12 07:12:56,838 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl$GetThread [pool-5-thread-2, , ] ----------------------------------------
2023-02-12 07:12:56,945 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , IOException SSLHandshakeException
2023-02-12 07:12:56,946 ERROR com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , Exception - Received fatal alert: handshake_failure
2023-02-12 07:12:56,946 INFO com.emc.esrs.connectivityreport.service.ConnectivityReportServiceImpl [pool-5-thread-1, , ] Host: esrs3-core.emc.com Port: 443 , SSLException or SSLHandshakeException. Consider this as success as just we are checking connectivity to backend core enterprise server.

捕获的网络跟踪 Tcpdump 命令指示 SCG-VE 可以通过端口 443 和 8443 连接 Dell Enterprise 服务器。

默认情况下，安全连接网关使用 1500 MTU 大小连接到 Dell Enterprise 服务器。但是，客户的 Internet 提供商不允许 1500 MTU 大小。

直接在 SCG-VE 上执行以下命令，以将 MTU 大小更改为 1454。
更改 SCG-VE 上 eth0 的 MTU 大小无法解决问题，因为 SCG-VE 上名为“esrsde-app”的其中一个容器连接到戴尔后端。

检查 sae-srs-bridge 的当前 MTU 大小：

ifconfig sae-srs-bridge

# ifconfig sae-srs-bridge
sae-srs-b Link encap:Ethernet  HWaddr 02:42:25:62:85:66
          inet addr:172.18.0.1  Bcast:172.18.0.7  Mask:255.255.255.248
          inet6 addr: fe80::42:25ff:fe62:8566/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2472 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2528 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:12309976 (11.7 Mb)  TX bytes:289066 (282.2 Kb)

在执行任何更改之前先拍摄虚拟机的快照，详情如下：

docker network disconnect sae-srs-bridge saede-app
docker network disconnect sae-srs-bridge esrsde-app
docker network disconnect sae-srs-bridge esrsalert-app
docker network rm sae-srs-bridge
docker network create --driver bridge --subnet 172.18.0.1/29 --opt com.docker.network.bridge.name=sae-srs-bridge --opt com.docker.network.driver.mtu=1454 sae-srs-bridge
docker network connect sae-srs-bridge esrsde-app
docker network connect sae-srs-bridge saede-app
docker network connect sae-srs-bridge esrsalert-app

验证：

ifconfig sae-srs-bridge

# ifconfig sae-srs-bridge
sae-srs-b Link encap:Ethernet  HWaddr 02:42:DE:D8:AB:D2
          inet addr:172.18.0.1  Bcast:172.18.0.7  Mask:255.255.255.248
          inet6 addr: fe80::42:deff:fed8:abd2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1454  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:7 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:746 (746.0 b)

仅供参考：
如果在上述更改后无法访问 UI，则 重新启动 虚拟机并等待 4 分钟，以便容器初始化。或者重新启动服务 systemctl restart esrsve.service。