TCP/IP详解-卷一

Steven的名著TCP/IP详解，第一卷，第2版。
这个对于TCP/IP协议簇中的各个协议大体的进行了一下介绍。
2012.8.31
第1章 introduction
1. Gageway:是进行协议转换的，例如http协议转换为FTP协议,它可以使路由器，也可以是别的东西
2. 以前是circuit switch,也就是模拟信号交换；后来改为数字 circuit switch;最后改为现在的包交换，也就是将数据缓存为字节包，进行数据switch(因为不说话是也占用线路，浪费资源）
2012.9.3
3. Connection-oriented networks, whether built on circuits or packets, were the most prevalent form of networking for many years. In the late 1960s, another option was developed known as the datagram. 
a datagram is a special type of packet in which all the identifying
information of the source and final destination resides inside the packet itself
(instead of in the packet switches). Although this tends to require larger packets,
per-connection state at packet switches is no longer required and a connectionless
network could be built, eliminating the need for a (complicated) signaling protocol.
Datagrams were eagerly embraced by the designers of the early Internet, and
this decision had profound implications for the rest of the protocol suite.
//原来许多网络的疑惑，看看这本书就明白了，汗颜!
4. SCTP was designed for carrying signaling messages on IP networks that resemble those
used in the telephone network.
5. Standard port numbers are assigned by the Internet Assigned Numbers
Authority (IANA). The set of numbers is divided into special ranges, including the
well-known port numbers (0–1023), the registered port numbers (1024–49151), and
the dynamic/private port numbers (49152–65535).
6. W3C定义应用层协议如HTML, IETF定义Link层之上应用层之下的协议，IEEE和3GPP定义物理层和Link层的东西。
2012.9.6
第2章
1. mac地址48位，IPV6 128位,我还真担心mac地址不够用
2. 2.3.6 IPV6
3. 48位MAC地址是EUI-48标准，还有EUI-64标准
4.  2.3.6.1中，给出了ifconfig的IPv6的地址的解释   不错!
5. CIDR类似子网掩码，但是不仅仅在本地使用，在核心路由器上可以识别，提供大于256小于65536个主机的网络地址
6. 怎么判断一个地址是IPv4，还是IPv6? IP的报文中好像有一个版本号的字段
7. 在双方通信时，必须协商IP协议版本号，否则无法通信。
8. IP地址信息查询：
AfriNIC—African Network
Information Centerhttp://www.afrinic.netAPNIC—Asia Pacific Network
Information Centerhttp://www.apnic.netARIN—American Registry for
Internet Numbershttp://www.arin.netLACNIC—Regional Latin
America and Caribbean IP
Address Registryhttp://lacnic.net/en/index.htmlRIPE NCC—Réseaux IP
Européenshttp://www.ripe.net  9. 为什么有MAC标示网卡，还需要IP地址标识host？ 因为根据IP可以划分子网等在，这些MAC无法实现。另外，不同层用不同的东西标识，方便配置。
2012.9.10
第3章 Link Layer
1. Ethernet一开始是使用共享电缆(shared physical cable)来通信，后来到1990s,10BASE-T开始使用双绞线和交换机星型拓扑全双工来通信了。
2. 虚拟局域网使用的原因是：随着交换机的大量使用，局域网中广播时，导致大量的数据包传输，所以提出虚拟局域网的方法，来解决广播时数据包过多的问题，标准为802.1q
3. 这章列出了所有的802标准，并进行了简单介绍
4. Note that because of VLANs, two hosts attached to the same switch but operating on different VLANs require a router between them for traffic to flow. Combination switch/router devices have been created to address this need
5.  Linux 中可以对于网络端口上输出的数据包进行VLAN ID的设置：The Linux command for manipulating 802.1p/q information is called vconfig.
6. 802.3ad standard link aggregation可以将笔记本的两个网卡绑定为一个网卡，这样可以使用这个虚拟的网卡来同时使用两个物理的网卡!!
7. linux网络工具ethtool
8. 802.x流控帧
9.  STP扩展树协议，用来保证多个交换机互联形成环路时，网络能够正常工作!
10. In a wireless environment, collision detection is not practical because it is difficult for a transmitter and receiver to operate simultaneously in the same piece of equipment and hear any transmissions other than its own, so collision avoidance is used instead
     也就是说,WIFI很难实现双工？？
11. 802.11n uses MIMO- orthogonal frequency division multiplexing (OFDM)
12. WIFI mesh网802.11s
13. 隧道技术(VPNs):For example, IPv4 can be carried in an IPv4 or IPv6 packet; Ethernet can be carried in a UDP or IPv4 or IPv6 packet,and so on.
2012.9.21
第4章 ARP
1. IP protocol is designed to provide interoperability of packet switching across a large variety of physical network types
2.  Generally,network interface hardware has one primary hardware address (e.g., a 48-bit value for an Ethernet or 802.11 wireless interface).
3. Knowing a host’s IP address is insufficient for the system to send a frame to that host efficiently on networks where hardware addresses are used. The operating system software (i.e., the Ethernet driver) must know the destination’s hardware address to send data directly. For TCP/IP networks, the Address Resolution Protocol (ARP) [RFC0826] provides a dynamic mapping between IPv4 addresses and the hardware addresses used by various network technologies. ARP is used with IPv4 only; IPv6 uses the Neighbor Discovery Protocol, which is incorporated into ICMPv6
4. PARP现在很少用了，一般在无盘工作站或Xterm中使用
5. 交换机知道所有的与他相连的PC的MAC地址，所以当在这个subnet中数据交换时，就可以根据MAC地址来进行导航，选择从哪一个Port上发出去.
6. ARP is used in multi-access link-layer networks running IPv4, where each host has its own primary hardware address. Point-to-point links such as PPP do not use ARP.
7. Using ARP to Set an Embedded Device’s IPv4 Address
第5章
1. network byte order是big endian byte order,也就是The 4 bytes in a 32-bit value are transmitted in the following order: bits 0–7 first, then bits 8–15, then 16–23, and bits 24–31 last
2. 为什么要有大端和小端？ 因为计算机是按字节byte来存储的，当一个32位的数存储时，该如何呢？ 把32位数的高位放高地址就是小端存储!
3. 路由协议RIP, OSPF, BGP, and IS-IS等负责建立路由表，路由器根据路由表将数据包发送到到next-hop,即下一个路由器。
4. 数据包在传输的过程中，MAC一直在变，而IP不变! 请看Fig.5-16
5. traceroute, tracert
6. Indeed, most hosts and most routers at the edge of the Internet can use a default route for everything other than destinations on local networks because there is only one interface available that provides connectivity to the rest of the Internet.
7. 手机等设备移动时，2layer会连入不同的设备，这时如果IP地址不发生变化，中断发送的数据包如何处理，很大的麻烦。所以提出了Mobile IP.
第6章 DHCP
1. 1. an IP address, subnet mask, and the IP address of a DNS server and router are the “bare essentials” to get a system running on the Internet that is capable of using or providing popular services such as Web and e-mail. To use Mobile IP, a system also needs to know how to find a home agent.(这东西和本地与漫游类似吗？)
2.  Such devices usually use DHCP to acquire their IP address, subnet mask, router IP address, and DNS server IP address.
3. 微软DHCP推荐对于小的网络DHCP有效期为8天，而大的网络16-24天的有效期
4.  DHCP使用UDP协议
5. DHCP messages are essentially BOOTP messages with a special set of options
6. In response to the increased use of mobile computers and smartphones accessing the Internet with cellular technology, frameworks and related DHCP options have been specified to convey information about the cellular configuration and handovers between different wireless networks. At present, there are two sets of DHCP options relating to this information: IEEE 802.21 Mobility Services (MoS) Discovery and Access Network Discovery and Selection Function (ANDSF).
  为了适应手机通信，所以DHCP新增加了选项!!!
2012.9.24
第7章 Firewalls and NAT
1. firewall分为两种，packet-filtering firewalls and proxy firewalls。proxy firewalls主要包括两种HTTP proxy firewalls and SOCKS firewalls
2. NAT包括两种，基本型只进行IP地址变化；而NAPT进行地址和端口号两个的变化。
3. NAT也很复杂，根据不同的数据包，进行不同的改变。
4. Linux iptables 防火墙
5. NAT真的好复杂，如果碰到一定再来看一看!!!!
2012.10.8
第8章 ICMPv4 and ICMPv6: Internet Control Message Protocol
1. ICMP是IP层的一部分,使用IP protocol
2. traceroute工具
2012.10.8
第9章 Broadcasting and local multicasting (IGMP and MLD)
1. IPV4支持unicast,anycast,multicast,broadcast, IPV6不支持boradcast
2. netstat 工具
3. IGMP处理多个路由器之间multicast路由
4. IGMP是IP layer的一部分。
2012.10.9
第10章 UDP and IP Fragmentation
1. Teredo: Tunneling IPv6 through IPv4 Networks
2. IP层对数据包进行分片打散
2012.10.10
第11章 Name Resolution and the DNS
2012.10.10
第12-17章都是在讲TCP协议, TCP占得篇幅真大呀!!! 真大!!!
    12章 TCP
    13章 TCP connection management
    14章 TCP timeout and retransmit
    15章 TCP data flow and window management
    16章 TCP Congestion Control
    17章 TCP Keepalive
第18章 Security: EAP,IPsec,TLS,DNS security, DKIM
1. 介绍一些基本的安全的知识，包括CA, PKI等
2.各层的安全协议有：
    link layer ： 8902.1x(EAPoL), 802.1AE(MACSec), 802.11i/WPA2, EAP
   Network:    IPsec(ESP)
   Transport:  TLS,DTLS,PANA
  Application:  DNSSEC, DKIM, EAP, Diameter,RADIUS,SSH,Kerberos, IPsec(IKE)
2012.10.10