安全連線閘道虛擬版本 （虛擬裝置/SCG-VE）：無法註冊安全連線閘道

即使本機系統可透過連接埠 443 和 8443 連線至 Dell Enterprise 伺服器，註冊安全連線閘道仍失敗，並出現下列錯誤。

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.

擷取的網路追蹤 Tcpdump 命令表示 SCG-VE 可透過連接埠 443 和 8443 連接 Dell Enterprise 伺服器。

安全連線閘道預設使用 1500 MTU 大小連線至 Dell Enterprise 伺服器。但是，客戶的網際網路提供者不允許 1500 MTU 大小。

直接在 SCG-VE 上執行以下命令，將 MTU 大小變更為 1454。
在 SCG-VE 上變更 eth0 的 MTU 大小無法解決此問題，因為在 SCG-VE 上名為「esrsde-app」的其中一個 docker 會連線至 Dell 後端。

檢查 sae-srs-bridge 目前的 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)

請在執行任何變更前先拍攝虛擬機器的快照，詳情如下：

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

證：

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)

僅供參考：
如果在上述更改后無法訪問UI，請 重新啟動 虛擬機並等待4分鐘，讓容器初始化。或重新啟動服務 systemctl restart esrsve.service。