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I found this by pure accident and a little curious as to why is there 2 active connections, on 2 different ports present between my system and stackoverflow. I was doing something else with the network on my system, and when I used just netstat below is what I got.
I thought it must the number of open browser tabs or stackoverflow webpages that are open, but even when I close them and study after like 10 mins, these 2 still reflect. Even though they are in the TIME_WAIT which upon research I came to know, that my system has closed the connection and is waiting for remaining packets to flush out,but I still dont have a clue about these connections.
Any ideas?
Note the "state" on those connections; TIME_WAIT means that the connection is closed but that it hasn't aged out of the connection table yet. It's also not at all uncommon for those connections to stay ESTABLISHED, since browsers will generally use HTTP Keep-Alive to avoid having to open new connections for every page request.
StackOverflow isn't 'maintaining' anything more than your browser is. Those connections are fully closed. The port is in TIME_WAIT state, which only lasts a couple of minutes after the final close. However there can be idle connections in ESTABLISHED state due to HTTP keep-alive.
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Closed 2 years ago.
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How do I connect from OpenWrt with ShadowSocks to my server and redirect all traffic through that connection?
I have a ShadowSocks server running on my server. Its working (as tested with my laptop).
Now I want to configure this on my GL-MT300A with OpenWrt. There is the ShadowSocks section in the OpenWrt config, but I don't know what to setup for Transparent Proxy, SOCKS5 Proxy and Port Forward.
I did add my ShadowSocks server under "Servers Manage", with the details I would otherwise have in my shadowconfig-client.json file.
All services (Transparent Proxy, SOCKS5 Proxy and Port Forward) are listed above as NOT RUNNING (see image). How do I start those or do I need those for my ShadowSocks client anyways?
I contacted support, and there seems to be an issue with MT300x models. You solve this by running the following from ssh on your router:
ln -s /usr/lib/libsodium.so.13.1.0 /usr/lib/libsodium.so.18
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Closed 5 years ago.
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I am searching for documentation related to the cloud acceleration feature of UC Browser, but can't find any useful resource.
Chrome's data saver feature is documented well. Is there any similar document that explains the UC Browser's cloud acceleration feature in detail? I specifically need answers to the following questions, if anyone can help:
Does UC Browser proxy HTTPS requests too through their cloud servers? If so, how does it handle caching in this scenario?
How does the proxy server identify itself to the origin server, and how does it forward user's IP address to the origin?
Does the UC Browser's cloud server cache static resources?
The proxy servers are known to compress/minify/optimize resources. How does it work with Subresource Integrity?
Does proxy server support Brotli encoding both ways (origin to proxy and proxy to browser)?
Can anyone help me on this?
Features like cloud acceleration and other data saving technologies won't touch https resources. Proxy servers often add an extra header 'X-FORWARDED-FOR' containing user IP. Probably UC optimizes the images and caches a smaller images by scaling down its dimensions. The subresource integrity is a client side check and browser can decide how to implement it and UC Browser doesn't support it yet.
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Closed 5 years ago.
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I am trying to setup HMA VPN my remote server on Amazon EC2 machine (Ubunutu 12.04.02), so that the ip of the outgoing traffic changes.
But as soon as the HMA script start vpn connection, SSH connection from my local machine to the server gets lost.
I think the problem lies with VPN client locking the network adapter so that SSH server is no longer able to listen to the same port as it was listening to earlier.
Please suggest what might be causing this problem?
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Closed 10 years ago.
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I was trying to install Fiddler2 to capture some HTTPS traffic in order to troubleshoot a slow file upload speed issue between client(windows 7) to a web server(Windows 2008 R2).
One strange thing I have noticed was the file uploading process became super fast after I have fiddler up and running. Could it because the fiddler started acting as a proxy server and using port 8888?
Why is it when I start using Fiddler2 the upload process speeds up?
Is this a WebDav request? Or a file upload through a traditional HTML form?
For WebDAV:
Most likely, this is due to a bug in the Microsoft WebDAV implementation, whereby they waste a bunch of time trying to "Automatically Detect" your proxy server over and over again via WPAD. This can be very slow in an environment without such a proxy server.
Fiddler caches the result of a proxy detection once at startup and sets itself as the system proxy, which prevents the WebDAV stack from incorrectly rerunning the WPAD algorithm over and over.
For a HTML Form:
Typically, this would mean that the client's buffer sizes were poorly chosen (IE6 had this problem) and thus the client isn't making good use of the network. Fiddler uses better buffer sizes (32k or 64k, IIRC) and hence makes better use of the network, reducing transfer times. Most modern browsers use buffer sizes chosen to optimize performance.
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Closed 10 years ago.
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I do use passive ftp in my software so that customer can download the software updates.Now my doubt is that if there are so many request to ftp(for downloading updates) then can passive ftp port can manage all requests?How does it work exactly?
A well-written generic server can handle tens of thousands of connections on a single port, no problem. The client IP/Port are part of the connection, so you can theoretically have millions of connections on a single port.
With FTP PASV transfers, the server provides an additional Port for your clients to connect to for transferring the file body outside of the control channel.
A naive server will simply bind a single ephemeral port per outstanding transfer. This will lead to an upper bound of well above 30,000.
Some FTP servers will let you configure a PASV port range which can make this number much smaller, which can restrict the number of concurrent users connected to your server in a naive implementation.
A more advanced FTP server implementation will allow multiple clients to connect to the PASV transfer ports, and use the clients' public IPs to manage which files are being requested or sent per public IP.
Realistically, if you're using a wide port range, you're more likely to run into bandwidth, CPU, Disk, or other system constraints on your server than you are to hit some kind of networking/port range limitation.