Figure 2 depicts a captured packet with a TCP header highlighted in a large red frame. The size of the TCP header is determined by the Header Length parameter, also known as Data Offset. In this example, the he
(fragmentation) TCP报文header 通常没有Options ,故header长度为20字节 对于TCP协议来说,整个包的最大长度是由最大传输大小(MSS,Maxitum Segment Size)决定,MSS就是TCP数据包每次能够传输的最大数据分段,这个值在SYN协商时确定。对于一个以太网来说,TCP的最大报文段长度即MSS一般是1460字节(1500(MTU) - 20(IP...
在函数tcp_connect中,使用tcp_mstamp_refresh函数,保存发送时间戳到tcp_mstamp(实际上其表示最近一次发送/接收的时间,单位时毫秒)。并且由变量retrans_stamp保存SYN报文的发送时间戳。 int tcp_connect(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); tcp_connect_init(sk); tcp_init_nondata_skb(...
Configuration Protocol (DHCP) [RFC2131] provides a framework for automatic configuration of IP hosts. The document "DHCP Options and BOOTP Vendor Information Extensions" [RFC2132] describes options for DHCP, some of which can also be used with BOOTP. Additional DHCP options are described in other...
This article is part two in a series covering the great tcpdump utility. You can use this utility to capture network traffic for troubleshooting and analysis...
curl -v --header "Accept-Encoding:deflate" http://localhost:3000 * Rebuilt URL to: http://localhost:3000/ * Trying 127.0.0.1... * TCP_NODELAY set * Connected to localhost (127.0.0.1) port 3000 (#0) > GET / HTTP/1.1 > Host: localhost:3000 ...
This article is the final part of my three-part series covering 18 different tcpdump tips and tricks where I continue to demonstrate features t...
options, with the exception ofTCP_BSDURGENT, are defined in theWs2ipdef.hheader file which is automatically included in theWs2tcpip.hheader file. TheTCP_BSDURGENToption for historic reasons is defined in theMswsock.hheader file. TheWs2def.handWs2ipdef.hheader files should never be used ...
(tcp). A single DNS domain can map to multiple targets (servers) using SRV address records. Each SRV record includes the host name, port, priority, and weight. DNS SRV support was introduced in Connector/NET 8.0.19 to remove the need for clients to identify each possible host in the ...
SO_CONNOPTLENyesDWORDThe length, in bytes, of connect option data, not in the normal network data stream, that is sent with network requests to establish a connection. This option is used by legacy protocols such as DECNet, OSI TP4, and others. This option is not supported by the TCP/...