I know port 80 is one of well-know-port, but I am confused that if I build the website server process on other port except of 80, would it works when other client try to access this website server?
Port 80 is the default port for http. So connecting to http://domain would in essence send you to http://domain:80 (by default).
Port 443 is the default for https and would work the same way as stated for http above.
Any other port would require the you to do url:port to connect to. There are definitely ways to get around this (like forwarding) but I don't see the need for it and I think it causes more issues than anything.
You would also need to make sure that the new port is open, forwarded and can receive connections.
(Source for the first 2 paragraphs https://developer.mozilla.org/en-US/docs/Glossary/Port)
Related
Now i am getting super confused with how ports actually work ,
This is my understanding of ports. I know that port 80 is for HTTP protocol and port 443 is for HTTPS protocol, so whenever I access http://website.com [(name or ip)], it is converted to http://website.com:80 [(name or ip)], and when I access https://website.com [(name or ip)], it gets converted to https://website.com:443 [(name or ip)].
So, if i am accessing a website on another port, i.e, i have my local setup of either springboot or angular app, and they are HTTP endpoints,
and I access http://localhost:someportNumber (example: http://localhost:5000), how does that get translated to port, as I have explicitly specified port 5000, but HTTP works on port 80.
Can you please help me with my understanding of how ports works.
Till now I was clear on how ports work, but now when I think of it like this today, it challenges my understanding of ports.
I came across this conflict of understanding when I was learning about the services on Google Kubernetes Engine. In there I created a service of type nodeport, which had configs like
port: 443
targetPort: 443
nodePort: 31000
and when I accessed external ip address of one of the nodes https://[external-ip]:31000, it worked.
So I began to challenge my understanding and I can't wrap this around my head that how is it working.
PS:- It is not about the concept of NodePort/ClusterIP/LoadBalancer. But in general about how these ports work with protocol port http or https, with a port of application.
You can specify any port (such as 5000 in your example). The URI simply begins with http to indicate what protocol is used - it does not mandate the use of port 80. The address is then used to contact the host on the specified port (which will be port 80 unless a different port was specified). Upon successful connection, the client then expects the server to speak HTTP.
On the server side, there is just a program that is listening on a port, waiting for incoming connections.
In the old days, one wouldn't call a person at a company directly. Instead one would call the main company switchboard and ask for the person at some extension.
Operator: How can I help you?
You: Extension 123
Operator: Connecting you now
Think of a "port" like an extension at a company. The hostname/IP address is the phone number of the company, the port is the extension at that company.
Going back to the analogy, once you are connected to the phone extension, you have a conversation. Both parties have an expectation of the conversation to be had. For example, if I call the extension corresponding to sales, I can place an order while if I call the extension corresponding to recruitment, I can submit my resume. This relationship between the purpose of the call and the extension is by convention and is not implicit in the extension itself.
When you form a connection over the internet to some machine at port 80, the assumption is that we will be exchanging HTTP traffic. However if I form a connection to some machine at port 5000, then there is nothing to prevent THAT connection from also sending and receiving HTTP traffic. For example, if sales at my company can be contacted on extension 80 and you can place an order there may also be an additional extension (5000) which you can call to place other types of orders that aren't available at the 80 extension.
See also:
http://www.steves-internet-guide.com/tcpip-ports-sockets/
I've seen a lot of solution for redirecting a webserver, but I have a Ubuntu server that is running an application, not over a url. I'd like to redirect requests from https://ip to http://ip, without setting up a domain for this server.
I want the response from http://ip to be returned when https://ip is queried.
I've tried using iptables to redirect traffic from port 443 to 80, but this did not work as requests to https://ip could not get a response.
I also tried using firewall-cmd to allow traffic on port 443, but this did not work either.
Any help on this issue would be greatly appreciated!
By changing the port from 443 to 80, traffic doesn't magically change from HTTP to HTTPS. You can see the port number as a house number and the protocol as a secret knock to get in.
You need to have a service running (who knows the secret knock) on port (house number) 80, which understands the HTTPS protocol (the secret knock).
I have a play application running on port 8080. I currently forward to this by using
http://ip_address:8080
as my 'URL to forward to' in my forwarding service control panel.
The problem with this is: frame forwarding is used and I think this may be stopping Google Analytic for working.
I have control over DNS
A, CNAME, AAAA, TXT and NS records
&
DNS Service records
For other websites in the past running on port 80 I have simply created an A record with the destination as the server IP address, however because I am using port 8080 in this case, this does not work.
What is the best way to go about getting away from framed forwarding?
You can't put port numbers into the DNS resource record (there's a notable exception, namely SRV records, but as client support for those is rather spotty, those won't be much help). A nameserver commonly resolves hostnames to ip addresses - no directory/file names, no port numbers.
You can use a permanent redirect, which is a webserver facility, used to tell web clients to contact a different webhost. In order to use that, you need a webserver which responds to requests on port 80, and knows that requests concerning your zone must be redirected to your actual webserver. Very similar to the iframe solution you've been already using, but a permanent redirect instead of iframe.
If your reason for dropping the current iframe approach isn't that you, for example, want to get rid of decorative framing, ads, "branding" etc (with those, a permanent redirect would help), but want to cease using an intermediate webserver, adding another level of indirection to the queries, there's little you can do:
your firewall may be able to do port redirection, meaning that the incoming requests will hit your gateway/firewall on port 80, where the request is sent on to port 8080 where the webserver is actually listening. Another possibility could be, but requiring again another webserver, listening to port 80, to set up proxying: incoming requests to that webserver will be served from a cache on that server, which is populated and occasionally refreshed as result of that webserver querying your webserver on port 8080.
Even though with the latter suggestion an additional webserver will be existing, there'd be no visible indirection, as it would be transparent to clients: The web files are produced by the first server which is hit, even if they are once every so often taken from another server.
I have a ASP.NET MVC site set up in IIS7 on Win2K8 with a single SSL binding on Port 443. The team in charge of the server only has port 443 open for security reasons, but this shouldn't be any issue because that's the only binding I have and I'm not making any regular HTTP calls on port 80.
When I call my site, my main login page (using forms authentication) comes up in the browser (over HTTPS) which looks fine. However, as soon as I try to login I get the following error:
[SocketException (0x274d): No connection could be made because the target machine actively refused it 10.x.123.123:80]
Ok that is the correct IP assigned to the site, but I'm not making any calls on port 80. Why would I get this error if all I need is a SSL binding on port 443? Am I required to have port 80 open as well? I'm not making any calls internally that use port 80, unless MVC is doing something I'm unaware of that requires port 80.
When digging into the code it turns out that our service turned around and made additional REST calls to other parts of the same service using a HTTP url, thus causing the error.
Since I configured IIS to only allow SSL traffic and I had internal calls to a HTTP URL the error was generated. The root cause was that I forgot we were making RESTful calls within the code and those URLs had to be updated to their respective HTTPS counterpart.
I need to monitor my application from incoming http POST and GET requests originating from outside and sometimes inside the machine.
Is this possible?
Been using fiddler but this only does outgoing not incoming (from outside the machine) or have I configured it incorrectly?
This is for my web app that is meant to be receiving a POST from an external server.
What you need to do is configure Fiddler to work as a "reverse proxy"
There are instructions on 2 different ways you can do this on Fiddler's website. Here is a copy of the steps:
Step #0
Before either of the following options will work, you must enable other computers to connect to Fiddler. To do so, click Tools > Fiddler Options > Connections and tick the "Allow remote computers to connect" checkbox. Then close Fiddler.
Option #1: Configure Fiddler as a Reverse-Proxy
Fiddler can be configured so that any traffic sent to http://127.0.0.1:8888 is automatically sent to a different port on the same machine. To set this configuration:
Start REGEDIT
Create a new DWORD named ReverseProxyForPort inside HKCU\SOFTWARE\Microsoft\Fiddler2.
Set the DWORD to the local port you'd like to re-route inbound traffic to (generally port 80 for a standard HTTP server)
Restart Fiddler
Navigate your browser to http://127.0.0.1:8888
Option #2: Write a FiddlerScript rule
Alternatively, you can write a rule that does the same thing.
Say you're running a website on port 80 of a machine named WEBSERVER. You're connecting to the website using Internet Explorer Mobile Edition on a Windows SmartPhone device for which you cannot configure the web proxy. You want to capture the traffic from the phone and the server's response.
Start Fiddler on the WEBSERVER machine, running on the default port of 8888.
Click Tools | Fiddler Options, and ensure the "Allow remote clients to connect" checkbox is checked. Restart if needed.
Choose Rules | Customize Rules.
Inside the OnBeforeRequest handler, add a new line of code:
if (oSession.host.toLowerCase() == "webserver:8888") oSession.host = "webserver:80";
On the SmartPhone, navigate to http://webserver:8888
Requests from the SmartPhone will appear in Fiddler. The requests are forwarded from port 8888 to port 80 where the webserver is running. The responses are sent back through Fiddler to the SmartPhone, which has no idea that the content originally came from port 80.
I would install Microsoft Network Monitor, configure the tool so it would only see HTTP packets (filter the port) and start capturing packets.
You could download it here
Configure Fiddler as a 'reverse proxy' on Windows
(for Mac, see the link in Partizano's comment below)
I know there's already an answer suggesting this, however I want to provide the explanation and instructions for this that Telerik should have provided, and also cover some of the 'gotchas', so here goes:
What does it mean to configure Fiddler as a 'reverse proxy'?
By default, Fiddler only monitors outgoing requests from the machine on which you're running Fiddler
To monitor incoming requests, you need to configure Fiddler to work as a 'reverse proxy'
What this means is that you need to set Fiddler up as a 'proxy' that will intercept incoming http requests that are sent to a specific port (8888) on the machine where you want to listen to the incoming requests. Fiddler will then forward those requests to the web server on the same machine by sending them to the usual port for http requests (usually port 80 or 443 for https). It's actually very quick and easy to do!
The standard way to set this up with Fiddler is to get Fiddler to intercept all request sent to Port '8888' (since this won't normally be used by anything else, although you could just as easily use another port)
You then need to use the registry editor to get Fiddler to forward any http requests that Fiddler receives on port 8888, so that they're forwarded to the standard http port (port 80, port 443 for an https request, or another custom port that your web server is set to listen on)
NOTE: For this to work, any request you want to intercept must be sent to port 8888
You do this by appending :8888 to your hostname, for example like this for an MVC route:
http://myhostname:8888/controller/action
Walkthrough
Ensure Fiddler can accept remote http requests on port 8888:
Run Fiddler as administrator Go to Tools > Fiddler Options > Connections, and ensure that 'Allow remote computers to connect' is checked, and 'Fiddler listens on port' is set to 8888:
Configure Fiddler to forward requests received on port 8888 to port 80
Close Fiddler
Start REGEDIT
Create a new DWORD named ReverseProxyForPort inside HKEY_CURRENT_USER\SOFTWARE\Microsoft\Fiddler2.
Now set the DWORD value to the local port you'd like to re-route inbound traffic to (generally port 80 for a standard HTTP server)
To do this, right-click the DWORD you created and select 'Modify'. Ensure 'Base' is set to 'Decimal' and enter '80' (or another port) as the 'Value data':
Ensure that port 8888 is opened on the firewall
You must ensure that port 8888 is open to external requests (it won't be by default if your server is firewall-protected)
That's it! Fiddler should now be set up as a reverse proxy, to intercept all requests from port 8888 (so that you can view them in Fiddler), and it will then forward them to your web server to actually be handled.
Test a request
Restart Fiddler
To test that Fiddler is intercepting external requests, open a browser on the same machine where you've set up Fiddler as a reverse proxy. Navigate your browser to http://127.0.0.1:8888
This tests making a basic request to to port 8888
You should see the request intercepted by Fiddler
Now you can test a request from another machine, for example by making a request from a browser on another machine like this (where 'remoteHostname' is a hostname on the machine where you've set up Fiddler as a reverse proxy) :
http://remoteHostname:8888/controller/action
Alternatively, you can compose a request by using another instance of Fiddler on a remote machine, using a URL similar to the one above. This will allow you to make either a GET or a POST request.
IMPORTANT: Once you've finished viewing your request(s), go back to Tools > Fiddler Options > Connections and remove the 'Allow remote computers to connect' option, otherwise 3rd parties will be able to bounce traffic through your server
Guys found the perfect way to monitor ALL traffic that is flowing locally between requests from my machine to my machine:
Install Wireshark
When you need to capture traffic that is flowing from a localhost to a localhost then you will struggle to use wireshark as this only monitors incoming traffic on the network card. The way to do this is to add a route to windows that will force all traffic through a gateway and this be captured on the network interface.
To do this, add a route with <ip address> <gateway>:
cmd> route add 192.168.20.30 192.168.20.1
Then run a capture on wireshark (make sure you select the interface that has bytes flowing through it) Then filter.
The newly added routes will come up in black. (as they are local addresses)
Microsoft Message Analyzer is the successor of the Microsoft Network Monitor 3.4
If your http incoming traffic is going to your web server at 58000 port, start the Analyzer in Administrator mode and click new session:
use filter: tcp.Port = 58000 and HTTP
trace scenario: "Local Network Interfaces (Win 8 and earlier)" or "Local Network Interfaces (Win 8.1 and later)" depends on your OS
Parsing Level: Full
You might consider running Fiddler as a reverse proxy, you should be able to get clients to connect to Fiddler's address and then forward the requests from Fiddler to your application.
This will require either a bit of port manipulation or client config, depending on what's easier based on your requirements.
Details of how to do it are here: http://www.fiddler2.com/Fiddler/Help/ReverseProxy.asp
Use TcpView to see ports listening and connections. This will not give you the requests though.
In order to see requests, you need reverse of a proxy which I do not know of any such tools.
Use tracing to give you parts of the requests (first 1KB of the request).
Using Wireshark..
I have not tried this:
http://wiki.wireshark.org/CaptureSetup/Loopback
If that works, you could then filter for http/http contains GET/http contains POST traffic.
You might have to run two Wireshark instances, one capturing local, and one capturing remote. I'm not sure.
You can also try the HTTP Debugger, it has the built-in ability to display incoming HTTP requests and does not require any changes to the system configuration.