network-protocols

问题 I am trying to check preconditions for a certain piece of software. I have a set of scripts that goes through and checks for things such as disk space, memory availability, etc. I need to create a script that can check if certain ports are open and accessible. I am using the WMI to check other network configuration items, but cannot find any references to checking port availability. Anyone have any ideas where I can find a WMI construct to let me view and manage ports or any other ideas for

问题 I am trying to check preconditions for a certain piece of software. I have a set of scripts that goes through and checks for things such as disk space, memory availability, etc. I need to create a script that can check if certain ports are open and accessible. I am using the WMI to check other network configuration items, but cannot find any references to checking port availability. Anyone have any ideas where I can find a WMI construct to let me view and manage ports or any other ideas for

问题 I'm writing a network client for a given protocol using TCP and I'm having having some philosophical issues with the overall architecture of the thing. Sometimes it may happen that I don't have the whole request data and I may need to read a few more bytes than what's available at the moment, and I imagine sometimes I can get parts of another request after the one I want. What's the usual approach in this kind of situations? 回答1: TCP sockets are Stream-Oriented. That means that reading them

问题 I'm not able to understand how message framing using fixed size prefix length header works. It's said that a fixed size byte array is going to contain the length for message to be sent. But how would you define a fixed size byte array, specifically in Golang. Say this is my message: Hello Its length is 5. So if I want to send this through a tcp stream, to make sure I receive all the message on the other end I'd have to tell it how many bytes it should read. A simple header would be length

问题 I'm writing a network client for a given protocol using TCP and I'm having having some philosophical issues with the overall architecture of the thing. Sometimes it may happen that I don't have the whole request data and I may need to read a few more bytes than what's available at the moment, and I imagine sometimes I can get parts of another request after the one I want. What's the usual approach in this kind of situations? 回答1: TCP sockets are Stream-Oriented. That means that reading them

问题 I have gone through the RFC 4443 and 8201, perhaps I did not understand as I am new to some terminology described in these RFC but I want to understand the implication of using payload in ICMP packet to big message? As per the RFC 4443 Linkt to 4443 RFC The payload will contain as much of invoking packet not exceeding the minimum path MTU in packet to big message. I don't understand the use case of such payload, even in the RFC 8201 there is no mention about the usages of payload. only one

问题 I know there are a lot of different comminucation protocals like: http, tcp, ssh, socks5, SMTP, POP, etc. I also know that to achieve a comminication, we need to connect localhost:localport to remotehost:remoteport . For example, if we google something, we would connect a random local port to www.google.com: 80 . If we ssh a remote host, we would connect a random local port to remotehost: 22 . My question is: Are communication protocol Half-duplex or Full-duplex ? I guess the answer is Half

问题 I know there are a lot of different comminucation protocals like: http, tcp, ssh, socks5, SMTP, POP, etc. I also know that to achieve a comminication, we need to connect localhost:localport to remotehost:remoteport . For example, if we google something, we would connect a random local port to www.google.com: 80 . If we ssh a remote host, we would connect a random local port to remotehost: 22 . My question is: Are communication protocol Half-duplex or Full-duplex ? I guess the answer is Half

问题 I took a working ASP.NET Core 2.2 app, upgraded it to 3.0 and suddenly the app no longer works in Windows Server 2012. It comes up with the following: ERR_HTTP2_INADEQUATE_TRANSPORT_SECURITY Chrome: Firefox: It seems that before I had to opt into HTTP/2 and now its the default along with HTTP1.1. There is a post here https://github.com/aspnet/AspNetCore/issues/14350 but that is totally confusing with no real solution. I have tried all sorts of enabling / disabling insecure protocols but to no

问题 I took a working ASP.NET Core 2.2 app, upgraded it to 3.0 and suddenly the app no longer works in Windows Server 2012. It comes up with the following: ERR_HTTP2_INADEQUATE_TRANSPORT_SECURITY Chrome: Firefox: It seems that before I had to opt into HTTP/2 and now its the default along with HTTP1.1. There is a post here https://github.com/aspnet/AspNetCore/issues/14350 but that is totally confusing with no real solution. I have tried all sorts of enabling / disabling insecure protocols but to no