If there is a router doing NAT, especially a low end router with few resources, it will age the oldest TCP sessions first. To do this it sets the RST flag in the packet that effectively tells the receiving station to (very ungracefully) close the connection. this is done to save resources.

2011年10月12日 · TCP RST packet is the remote side telling you that the connection on which the previous TCP packet is sent is not recognized, maybe the connection has closed, maybe the port is not open, and something like these. Here is my opinion, since the connection is not valid any more, there is no need to reply an ACK.

2012年11月19日 · RST says: "There is no conversation. I won't say anything and I won't listen to anything you say." RST is useful if you have long lasting TCP connection with little traffic. If one of the computers is restarted, it forgets about the connection, and the other computer gets RST, as soon as it sends another packet.

2016年11月3日 · However, if host A wants to close the session after sending the packet, it would only send a [FIN] packet (nothing to acknowledge) but host B would respond with [FIN,ACK] (acknowledges the request and responds with FIN). Finally, some TCP stacks perform half-duplex termination, meaning that they can send [RST] instead of the usual [FIN,ACK ...

@EJP In socket programming terms, open means that something is accepting packets on a port, whereas closed means packets are either being rejected (aka RST) or ignored completely, usually due to a firewall. In firewall or system administrator terms, your definition can be used.

2016年8月16日 · You should read the TCP RFCs and make sure your TCP RST packet conforms to the requirements for this case. A malformed RST will be ignored by the client. RFC 1122 also indicates that ICMP Destination Unreachable containing codes 2-4 should cause an abort in the connection. It's important to note the codes because 0, 1, and 5 are listed as a ...

2011年9月27日 · What is the most common reason of TCP rst packet sent by either server or client ? I came to know from some online forums that it is due to session timeout? If it is due to session timeout, I believe TCP work on technology like packet retransmission,So in this case why not retransmission instead of...

2014年3月20日 · I am trying to debug a scenario, and for that I want the http server to close the connection via RST. Right now it is doing a graceful close with fin/ack. Is there any way I can manually send a RST packet to close the connection as part of the current stream? may be a simple custom server? thanks in advance for your help.

2014年6月4日 · I am trying to understand an issue between an NFS client and Server. When the server application crashes, the kernel sends a RST packet to client to which the client closes the old connection and initiates a new one by sending a SYN. Since the application is not ready at this point, the server again responds with a [RST, ACK].

2012年10月12日 · As you can read, when the server send data with an incorrect ACK, the client istead of resending the data, sends a RST packet (forcing the server to close the connection). In the client log I can see that receives and process the data sent by the server (So the connection is not closed when the server sends an incorrect ACK).