Selenium Grid: URL in RemoteWebDriver(url, caps) - selenium

Question

I am trying to run a test suite using selenium grid, and I was able to establish hub and one node. After this, when I am initializing the RemoteWebdiver(url, caps) call, it is throwing an exception:
org.openqa.selenium.WebDriverException: Error forwarding the new session Error forwarding the request Failed to connect to <IP>:<PORT>
Also when I ping to that "Node_IP", it shows 100% loss. But my grid console shows it is connected. I have added inbound and outbound rules for the port: 4444 through firewall. telnet command also fails for "Node_IP" and "PORT" which is "4444".
I can execute the tests in my local when I pass the URL as : http://localhost:4444/wd/hub
/**** Added Description *****/
hubConfig: java -jar selenium-server-standalone-3.13.0.jar -role hub -host "Host_IP"
nodeConfig: java -Dwebdriver.chrome.driver="chrome_driver_location_on_node" -jar selenium-server-standalone-3.13.0.jar -role node -hub http://"host_ip":4444/grid/register -browser
"browserName=chrome,platform=WINDOWS,version=67.0,maxInstances=5"
Same goes for FireFox and IE.
Code works fine as I am able to execute as a localhost.
The stacktrace is as:
FYI: "Node_PORT" is a random port. I have not assigned it. I also tried it by assigning a port but it didn't work too.
org.openqa.selenium.WebDriverException: Error forwarding the new session Error forwarding the request Failed to connect to /<Node_IP>:<Node_PORT>
Command duration or timeout: 51.98 seconds
Build info: version: '3.13.0', revision: '2f0d292', time: '2018-06-25T15:24:21.231Z'
System info: host: '<System_Info>', ip: <Hub_IP>, os.name: 'Windows Server 2008 R2', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_151'
Driver info: driver.version: RemoteWebDriver
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:214)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:166)
at org.openqa.selenium.remote.JsonWireProtocolResponse.lambda$new$0(JsonWireProtocolResponse.java:53)
at org.openqa.selenium.remote.JsonWireProtocolResponse.lambda$getResponseFunction$2(JsonWireProtocolResponse.java:91)
at org.openqa.selenium.remote.ProtocolHandshake.lambda$createSession$0(ProtocolHandshake.java:123)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.Spliterators$ArraySpliterator.tryAdvance(Spliterators.java:958)
at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126)
at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:498)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:485)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:126)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:73)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:136)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:548)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:212)
at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:130)
at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:143)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.openqa.grid.common.exception.GridException: Error forwarding the new session Error forwarding the request Failed to connect to /<Node_IP>:<Node_PORT>
at org.openqa.grid.web.servlet.handler.RequestHandler.process(RequestHandler.java:118)
at org.openqa.grid.web.servlet.DriverServlet.process(DriverServlet.java:86)
at org.openqa.grid.web.servlet.DriverServlet.doPost(DriverServlet.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.seleniumhq.jetty9.servlet.ServletHolder.handle(ServletHolder.java:860)
at org.seleniumhq.jetty9.servlet.ServletHandler.doHandle(ServletHandler.java:535)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.seleniumhq.jetty9.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.seleniumhq.jetty9.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:190)
at org.seleniumhq.jetty9.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
at org.seleniumhq.jetty9.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)
at org.seleniumhq.jetty9.servlet.ServletHandler.doScope(ServletHandler.java:473)
at org.seleniumhq.jetty9.server.session.SessionHandler.doScope(SessionHandler.java:1564)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
at org.seleniumhq.jetty9.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
at org.seleniumhq.jetty9.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.seleniumhq.jetty9.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.seleniumhq.jetty9.server.Server.handle(Server.java:530)
at org.seleniumhq.jetty9.server.HttpChannel.handle(HttpChannel.java:347)
at org.seleniumhq.jetty9.server.HttpConnection.onFillable(HttpConnection.java:256)
at org.seleniumhq.jetty9.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
at org.seleniumhq.jetty9.io.FillInterest.fillable(FillInterest.java:102)
at org.seleniumhq.jetty9.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
at org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:247)
at org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:140)
at org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)
at org.seleniumhq.jetty9.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:382)
at org.seleniumhq.jetty9.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:708)
at org.seleniumhq.jetty9.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:626)
at java.lang.Thread.run(Unknown Source)

Answer 1

I got the solution for my own query and it was a very simple one which I was aware of earlier but didn't gave any second thoughts for that.
Basically, I had to start the node with a specific port and I whitelisted that port number from the security groups.
Thanks again everyone who took an effort for answering. Hope this helps those who are stuck in a similar situation.