配置Google Cloud Compute防火墙以允许外部访问数据库服务器

我在Google Cloud Compute实例上安装了neo4j数据库，我想从笔记本电脑连接到数据库 .

[1] I have neo4j running on Google Cloud

● neo4j.service - Neo4j Graph Database
   Loaded: loaded (/lib/systemd/system/neo4j.service; disabled; vendor preset: enabled)
   Active: active (running) since Sat 2017-09-30 09:33:39 UTC; 1h 3min ago
 Main PID: 2099 (java)
    Tasks: 41
   Memory: 504.5M
      CPU: 18.652s
   CGroup: /system.slice/neo4j.service
           └─2099 /usr/bin/java -cp /var/lib/neo4j/plugins:/etc/neo4j:/usr/share/neo4j/lib/*:/var/lib/neo4j/plugins/* -server -XX:+UseG1GC -XX:-OmitStackTraceInFastThrow -XX:+AlwaysPreTouch -XX:+U
nlockExperimentalVMOptions -XX:+TrustFinalNonStaticFields -XX:+DisableExplicitGC -Djdk.tls.ephemeralDHKeySize=2048 -Dunsupported.dbms.udc.source=debian -Dfile.encoding=UTF-8 org.neo4j.server.Commu
nityEntryPoint --home-dir=/var/lib/neo4j --config-dir=/etc/neo4j
Sep 30 09:33:40 neo4j-graphdb-server neo4j[2099]:   certificates: /var/lib/neo4j/certificates
Sep 30 09:33:40 neo4j-graphdb-server neo4j[2099]:   run:          /var/run/neo4j
Sep 30 09:33:40 neo4j-graphdb-server neo4j[2099]: Starting Neo4j.
Sep 30 09:33:42 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:33:42.948+0000 INFO  ======== Neo4j 3.2.5 ========
Sep 30 09:33:42 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:33:42.988+0000 INFO  Starting...
Sep 30 09:33:44 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:33:44.308+0000 INFO  Bolt enabled on 127.0.0.1:7687.
Sep 30 09:33:47 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:33:47.043+0000 INFO  Started.
Sep 30 09:33:48 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:33:48.160+0000 INFO  Remote interface available at http://localhost:7474/
Sep 30 09:39:17 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:39:17.918+0000 WARN  badMessage: 400 No URI for HttpChannelOverHttp@27d4a9b{r=0,c=false,a=IDLE,uri=-}
Sep 30 09:46:18 neo4j-graphdb-server neo4j[2099]: 2017-09-30 09:46:18.374+0000 WARN  badMessage: 400 for HttpChannelOverHttp@6cbed0ca{r=0,c=false,a=IDLE,uri=-}

[2] I've created a firewall rule on Google Cloud to allow external access to the DB server

"google-db-server"的网络标记已添加到Google Cloud Compute服务器 .

我的期望是，下面的规则将允许任何外部计算机连接到Google Cloud Compute实例上的端口7474

user@machine:~/home$ gcloud compute firewall-rules create custom-allow-neo4j --action ALLOW --rules tcp:7474 --description "Enable access to the neo4j database" --direction IN --target-tags google-db-server

user@machine:~/home$ gcloud compute firewall-rules list --format json
[
  {
    "allowed": [
      {
        "IPProtocol": "tcp",
        "ports": [
          "7474"
        ]
      }
    ],
    "creationTimestamp": "2017-09-30T00:25:51.220-07:00",
    "description": "Enable access to the neo4j database",
    "direction": "INGRESS",
    "id": "5767618134171383824",
    "kind": "compute#firewall",
    "name": "custom-allow-neo4j",
    "network": "https://www.googleapis.com/compute/v1/projects/graphdb-experiment/global/networks/default",
    "priority": 1000,
    "selfLink": "https://www.googleapis.com/compute/v1/projects/graphdb-experiment/global/firewalls/custom-allow-neo4j",
    "sourceRanges": [
      "0.0.0.0/0"
    ],
    "targetTags": [
      "google-db-server"
    ]
  },

[3] Running nmap from the Google Cloud server instance shows that port 7474 is available locally, and I can telnet to that port locally

google_user@google-db-server:~$ nmap -p 22,80,443,7474 localhost
Starting Nmap 7.01 ( https://nmap.org ) at 2017-09-30 10:46 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000081s latency).
PORT     STATE  SERVICE
22/tcp   open   ssh
80/tcp   open   http
443/tcp  closed https
7474/tcp open   unknown
Nmap done: 1 IP address (1 host up) scanned in 0.03 seconds

google-user@google-db-server:~$ telnet localhost 7474
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

[4] However I am unable to connect from my laptop and nmap shows port 7474 as unavailable

user@machine:~/home$ nmap -p 22,80,443,7474 35.201.26.52

Starting Nmap 7.01 ( https://nmap.org ) at 2017-09-30 20:50 AEST
Nmap scan report for 52.26.201.35.bc.googleusercontent.com (35.201.26.52)
Host is up (0.28s latency).
PORT     STATE  SERVICE
22/tcp   open   ssh
80/tcp   open   http
443/tcp  closed https
7474/tcp closed unknown

Nmap done: 1 IP address (1 host up) scanned in 0.75 seconds

因此，尽管创建了防火墙规则以允许任何IP地址连接到tcp：7474上的Google Cloud Compute实例，但我仍然无法从笔记本电脑访问此端口 .

我错过了一些额外的步骤吗？