I built a simple Webserver with just the serve function from the std http module. It just redirects a request to a new URL:
import { serve } from "https://deno.land/std#0.120.0/http/server.ts";
serve(req => Response.redirect("https://google.com"))
It works, when I access the server through a browser on my laptop, where the server is running, but when I try to access it on another machine in the same network using the ip-address of my laptop, there simply is no response at all. Is this one of the security features Deno has and if so, how can you deactivate it?
Update:
So I tried looking up the requests I make on my local machine in Wireshark, but when I run the server and send a request, it doesn't show up there. I disabled my Wifi Connection to see if that changes anything and to my surprise, I still got an answer from the server when I sent a request through the browser. I came to the conclusion that the Deno server somehow doesn't serve over the local network which really confuses me. Is there a way to change that behaviour?
This is not related to Deno, but rather the firewall features of your device/router/network or an error in the method that you are using to connect from the other device (typo, network configuration, etc.).
Without additional configuration (by default), serve binds to 0.0.0.0:8000, so — as an example — if your laptop is assigned the local address 192.168.0.100 by your router, you could reach the server at the address http://192.168.0.100:8000.
You might want to do research on SE/NetworkEngineering and elsewhere to determine the cause of the blocked connection.
Related
I have a local jupyter lab instance, running on mint-2 computer with command jupyter lab --ip "*", and it listens to port 8888. I can access it just fine via the URL mint-2:8888.
I also have a server instance ubuntu-2. I reverse ssh tunnel from mint-2:8888 to ubuntu-2:8888, meaning I can access it on my mint-1 laptop just fine via the URL ubuntu-2:8888 anywhere in the world.
However, it is not encrypted with TLS, so I wanted to improve this. On ubuntu-2 I have an nginx load balancer container that strips https traffic, and redirects http traffic to other locations. I have set up jupyter.ubuntu-2:443 so that it redirects to ubuntu-2:8888 so that it redirects to mint-2:8888. This version initially seems to open up just fine, and I can navigate directories. However, whenever I want to launch a new terminal or notebook instance, or even create new directories, it wouldn't work. Here's the network log when I save a modified notebook:
My question is, why won't the requests go through, considering I can still interact with the interface just fine everywhere else, but just not when creating folders/notebooks/terminals. I am thinking that JupyterLab might be using UDP and I'm considering passing UDP traffic through nginx, but this doesn't really make sense, as this is clearly a PUT request. Any other help regarding where to find more logs or speculation on what might have gone wrong is much appreciated.
I dig into it a little more, and managed to figured it out.
JupyterLab has CORS policy that doesn't allow requests to ubuntu-2. I then added c.NotebookApp.allow_origin = "*" to JupyterLab's config at ~/.jupyter/jupyter_lab_config.py, as mentioned here.
Then I found out that everything is still not functional, and this is because Jupyter requires both HTTP and WebSocket protocols, and my current server setup only allows http traffic. So I need to enable generic TCP traffic on ubuntu-2's HAProxy load balancer. Because I have multiple virtual hosts on the server, I need to distinguish between them, so I used Server Name Indication, server name included in TLS traffic.
I am having very strange network problems. I am on a domain where a few servers are located on a different subnet. I can ping these servers, dns look them up and remote desktop to them by IP-address. I however cannot find them when using:
net view \server
or
Try to access them via windows explorer.
The person next to me who has an identical machine and is on the same subnet has no problems, as a matter of fact, I am the only one in a 50 person company having this problem!
This wouldn't be so much of a problem except for the fact that my machine cannot use web services located on these servers, neither via HTTP or NET.TCP.
After trying everything I can find on the internet and some more (added a new network card, reset policies, etc.) I finally got WireShark to see what is going on. When doing net view \server I notice that the server never responds to "Session Setup Request" but it did respond to "Negotiate Protocol Request". So what could possibly cause the server never to responde to the Session Setup Request?
Here is the server side capture (Not same session)
OK I found out what this was by comparing my tcpip registry (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters) with a machine that worked. What I noticed is that I had the following 2 entries
EnablePMTUBHDetect 0
EnablePMTUDiscovery 1
but the other machine didn't. By deleting these entries, everything started working!
This however is very strange because these happen to be the default values for there registry keys so I do not understand why having these entries cause such a problem.
I am trying to intercept HTTP requests sent via an application I have installed on my Windows 7 machine. I'm not sure what platform the application is built on, I just know that Fiddler isn't correctly intercepting anything that this program is sending/receiving. Requests through Chrome are intercepted fine.
Can Fiddler be set up as a proxy for ALL applications, and if so, how would I go about doing this? I have no control over the application code, it's just something I installed. It is a live bidding auction program which seems to mainly display HTML pages inside the application window.
Fiddler isn't correctly intercepting anything that this program is sending/receiving
That means the program is either firing requests to localhost (very unlikely), or ignoring the proxy settings for the current user (most likely). The latter also means this application won't function on a machine where a proxy connection is required in order to make HTTP calls to the outside.
The alternative would be to use a packet inspector like Wireshark, or to let the application be fixed to respect proxy settings, or to capture all HTTP requests originating from that machine on another level, for example the next router in your network.
My website works fine on my local machine. And it also works fine, when I publish it, and access it over the Internet.
However, when I access it through my company's network (LAN), many requests state in the pending state and they won't return back either successfully, or with error. No IIS logs, no nothing.
After like 5 minutes, the request simply dies. No HTTP response is shown in Chrome's console. I guess it's a network problem. But I don't know how to debug it.
How should I debug this pending state?
This is more a problem for sys-ops than for development but you might need to verify/prove the problem is with the routers and not with your server or computer configuration.
The first tool you need is network analyzer, for this look no further than Wireshark. You'll need administrator permissions on your machine.
Wireshark is intuitive, but has a lot of features, you might want to read a tutorial or two on how to use it.
With Wireshark on your machine you can verify a TCP connection to the server is made or attempted. If you don't know how TCP works, now is the time to learn.
Based on the result you should have your answer of where the problem is:
No TCP SYN sent or sent to wrong IP: problem in your machine. Make sure the server is not redirected to localhost/wrong ip in the hosts file and verify no static routes have been added to your routing table.
Most likely no TCP SYN-ACK: The problem is in the network routing, you might want to install Wireshark on the server and verify the SYN packets are indeed not getting through. Get your sys-ops guys to fix the problem. Probably a misconfigured firewall rule.
Very unlikely: TCP connection established and HTTP request sent to server, but server does not respond. No idea, if the server responds to internet traffic it should respond to your traffic.
By the way if there are no sys-ops guys in your company to fix the problem, get the model of any configurable router between your computer and the server and try asking in Server Fault (or get a consultant).
I'm doing some test hosting of an asp.net program I created
I can access it fine from the local machine (both debugging and pointing the virtual directory to it)
I can also access (local) by using the localhost or using the ip
however when i get on a different machine on the same network (i can ping my machine)
I get the following error:
Connection Interrupted
The connection to the server was reset while the page was loading.
The network link was interrupted while negotiating a connection. Please try again.
Does anyone have any idea what I'm doing wrong?
Crash893
EDIT:
I have duplicate this question on serverfault.com
I would generally take a snapshot of the network traffic with Wireshark (or other network sniffer) and see what is happening on the wire. Compare this to a site that works. Windows firewall, a browser proxy, or some other network software may be at fault.