1.IPv6概念
IPv6是InternetProtocol Version 6的縮寫。IPv6是IETF(互聯網工程任務組,InternetEngineering Task Force)設計的用於替代現行版本IP協議(IPv4)的下一代IP協議。
2.IPv6與IPv4相比具有的優勢
a,IPv6具有更大的地址空間。IPv4中規定IP地址長度爲32,即有2^32-1個地址;而IPv6中IP地址的長度爲128,即有2^128-1個地址。
b,IPv6使用更小的路由表。IPv6的地址分配一開始就遵循聚類(Aggregation)的原則,這使得路由器能在路由表中用一條記錄(Entry)表示一片子網,大大減小了路由器中路由表的長度,提高了路由器轉發數據包的速度。
c,IPv6增加了增強的組播(Multicast)支持以及對流的支持(FlowControl),這使得網絡上的多媒體應用有了長足發展的機會,爲服務質量(QoS,Qualityof Service)控制提供了良好的網絡平臺。
d,IPv6加入了對自動配置(AutoConfiguration)的支持。這是對DHCP協議的改進和擴展,使得網絡(尤其是局域網)的管理更加方便和快捷。
e,IPv6具有更高的安全性。在使用IPv6網絡中用戶可以對網絡層的數據進行加密並對IP報文進行校驗,極大的增強了網絡的安全性。
3.IPv6的三種常規表示形式
1)十六進制:3FFE:FFFF:7654:FEDA:1245:BA98:3210:4562
2)壓縮形式:例如,多路廣播地址 FFED:0:0:0:0:BA98:3210:4562 的壓縮形式爲 FFED::BA98:3210:4562。單播地址3FFE:FFFF:0:0:8:800:20C4:0 的壓縮形式爲 3FFE:FFFF::8:800:20C4:0。環回地址0:0:0:0:0:0:0:1 的壓縮形式爲 ::1。未指定的地址 0:0:0:0:0:0:0:0 的壓縮形式爲 ::。
3)混合形式
此形式組合 IPv4 和 IPv6 地址。在此情況下,地址格式爲 n:n:n:n:n:n:d.d.d.d,其中每個 n 都表示4個 IPv6 高序位 16 位地址元素之一的十六進制值,每個 d 都表示 IPv4 地址的十進制值。
4.IPv6 協議棧的安裝及 IPv6 地址設置
a)windows下IPv6設置
(1) IPv6 協議棧的安裝:在 開始 --> 運行 處執行 ipv6 install
(2) IPv6 地址設置:在 開始 --> 運行 處執行 netsh 進入系統網絡參數設置環境,然後執行interface ipv6。畫面顯示:netsh interface ipv6>然後再執行:add address “本地連接” 2001:f80:754::3
(3) IPv6默認網關設置:在上述系統網絡參數設置環境中執行:add route ::/0 “本地連接” 2001:f80:754::1 publish=yes
(4) IPv6地址刪除:在 開始 --> 運行 處執行 netsh 進入系統網絡參數設置環境,然後執行interface ipv6。畫面顯示:netsh interface ipv6>然後再執行:delete address “本地連接” 2001:f80:754::11 (注:必須以管理員身份運行CMD)
b)linux下IPv6的設置(linux內核自2.2.0開始都是支持IPv6內核這個模塊的)
(1)手動添加IPv6地址和默認路由
#ifconfig eth0 add 2001:f80:754::2/64 (或如下)
#ifconfig eth0 inet6 add 2001:f80:754::2/64
#route -A inet6 add default gw 2001:f80:754::1/64 (配置時,沒有修改默認漏油也沒有出現過什麼問題!)
//#ifconfig eth0 del 2001:f80:754::2/64 (delete)
(2)通過修改配置文件/etc/rc.local,配置文件下添加IPv6地址和默認路由
#vi /etc/rc.local (打開該文件)
#fconfig eth0 add 2001:f80:754::2/64 (IPv6地址)
#route -A inet6 add default gw 2001:f80:754::1/64 (默認路由)
5.使用IPv4 及 IPv6 地址socket通信的一些demo
爲了編程的方便,一般我喜歡把socket通信有關的頭文件都包含進來,省得麻煩,如下的頭文件mynet.h
<span style="font-size:12px;">/*mynet.h*/
#include <netinet/in.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/file.h>
#include <sys/types.h>
#include <netinet/ip.h>
#include <arpa/ftp.h>
#include <arpa/inet.h>
#include <arpa/telnet.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <net/if.h>
#include <stdlib.h>
#include <unistd.h>
#include <error.h>
#include <ifaddrs.h>
#include <netdb.h> </span>
首先實現的是IPv4下的TCP連接,如下代碼實現server:
/*tcpipv4serv.c*/
#include "mynet.h"
#define MyPort 10086
#define MyNum 20
int main(int argc,char* argv[]){
int mysock;
int clientfd;
int bytes = 0;
int len = sizeof(struct sockaddr_in);
struct sockaddr_in myaddr;
struct sockaddr_in cliaddr;
char *sendbuf = "hello client,i have recv msg";
char recvbuf[256];
char clientip[INET6_ADDRSTRLEN];
mysock = socket(AF_INET, SOCK_STREAM, 0);
if(mysock < 0){
printf("Error at socket().\n");
return -1;
}
myaddr.sin_family = AF_INET;
myaddr.sin_addr.s_addr = htonl(INADDR_ANY);
myaddr.sin_port = htons(MyPort);
if( bind(mysock, (struct sockaddr*)&myaddr, sizeof(myaddr)) < 0 ) {
printf("bind() failed. \n");
close(mysock);
return -1;
}
if(listen(mysock, MyNum) < 0) {
printf("Error listening on socket.\n");
close(mysock);
return -1;
}
printf("server listen...\n");
memset(&cliaddr, '0', sizeof(cliaddr));
for(;;){
clientfd = accept(mysock, (struct sockaddr*)&cliaddr, &len);
memset(recvbuf, '\0', sizeof(recvbuf));
if( bytes = recv(clientfd, recvbuf, sizeof(recvbuf), 0) < 0 ) {
printf("recv error!\n");
} else {
inet_ntop(AF_INET, &cliaddr.sin_addr, clientip, INET6_ADDRSTRLEN);
printf("C:%s->S: %s\n", clientip, recvbuf);
memset(recvbuf, '\0', sizeof(recvbuf));
if( bytes = send(clientfd, sendbuf, strlen(sendbuf)+1, 0) < 0 ) {
printf("recv error!\n");
} else {
printf("S->C:%s\n", sendbuf);
}
}
}
closesocket(mysock);
closesocket(clientfd);
return 0;
}
以下的代碼是client端:
<span style="font-size:12px;">#include "mynet.h"
#define MyPort 10086
int main(int argc,char* argv[]){
struct sockaddr_in servaddr;
int mysock;
int bytes = 0;
int len = sizeof(struct sockaddr_in);
char mybuff[256];
if( argc != 3){
printf("usage: <exe> <serverip> <port>\n");
return -1;
}
mysock = socket(AF_INET, SOCK_STREAM, 0);
if(mysock < 0){
printf("Error at socket().\n");
return -1;
}
memset(&servaddr, 0, len);
servaddr.sin_family = AF_INET;
//servaddr.sin_addr.s_addr = htonl(atol(argv[1]));
inet_pton(AF_INET, argv[1], &servaddr.sin_addr);
servaddr.sin_port = htons(atoi(argv[2]));
if(connect(mysock,(struct sockaddr *) &servaddr, len) < 0){
printf("connect error!\n");
return -1;
}
memset(mybuff,0,sizeof(mybuff));
printf("Client Send:");
gets(mybuff);
bytes = send(mysock, mybuff, strlen(mybuff), 0);
if( bytes>0 ){
memset(mybuff,0,sizeof(mybuff));
}
bytes = recv(mysock, mybuff, sizeof(mybuff), 0);
if (bytes>0)
{
printf("client recv:%s\n", mybuff);
memset(mybuff,0,sizeof(mybuff));
}
}</span>
通過使用gcc 命令分別編譯成tcpipv4serv和tcpipv4cli這兩個可執行文件,如下圖
圖1-1 執行tcp server
圖1-2執行tcp client
一下將貼出IPv6的server和client
<span style="font-size:12px;">/*tcpipv6serv.c*/
#include "mynet.h"
#define MyPort 10086
#define MyNum 20
int main(int argc,char* argv[]){
int mysock;
int clientfd;
int bytes = 0;
int len = sizeof(struct sockaddr_in);
struct sockaddr_in myaddr;
struct sockaddr_in cliaddr;
char *sendbuf = "hello client,i have recv msg";
char recvbuf[256];
char clientip[INET6_ADDRSTRLEN];
mysock = socket(AF_INET, SOCK_STREAM, 0);
if(mysock < 0){
printf("Error at socket().\n");
return -1;
}
myaddr.sin_family = AF_INET;
myaddr.sin_addr.s_addr = htonl(INADDR_ANY);
myaddr.sin_port = htons(MyPort);
if( bind(mysock, (struct sockaddr*)&myaddr, sizeof(myaddr)) < 0 ) {
printf("bind() failed. \n");
close(mysock);
return -1;
}
if(listen(mysock, MyNum) < 0) {
printf("Error listening on socket.\n");
close(mysock);
return -1;
}
printf("server listen...\n");
memset(&cliaddr, '0', sizeof(cliaddr));
for(;;){
clientfd = accept(mysock, (struct sockaddr*)&cliaddr, &len);
memset(recvbuf, '\0', sizeof(recvbuf));
if( bytes = recv(clientfd, recvbuf, sizeof(recvbuf), 0) < 0 ) {
printf("recv error!\n");
} else {
inet_ntop(AF_INET, &cliaddr.sin_addr, clientip, INET6_ADDRSTRLEN);
printf("C:%s->S: %s\n", clientip, recvbuf);
memset(recvbuf, '\0', sizeof(recvbuf));
if( bytes = send(clientfd, sendbuf, strlen(sendbuf)+1, 0) < 0 ) {
printf("recv error!\n");
} else {
printf("S->C:%s\n", sendbuf);
}
}
}
closesocket(mysock);
closesocket(clientfd);
return 0;
}</span>
<span style="font-size:12px;">/*tcpipv6cli.c*/
#include "mynet.h"
#define MyPort 10086
int main(int argc,char* argv[]){
struct sockaddr_in6 servaddr;
int mysock;
int bytes = 0;
int len = sizeof(struct sockaddr_in6);
char mybuff[256];
if( argc != 3){
printf("usage: <exe> <serverip> <port>\n");
return -1;
}
mysock = socket(AF_INET6, SOCK_STREAM, 0);
if(mysock < 0){
printf("Error at socket().\n");
return -1;
}
memset(&servaddr, 0, len);
servaddr.sin6_family = AF_INET6;
inet_pton(AF_INET6, argv[1], &servaddr.sin6_addr);
servaddr.sin6_port = htons(atoi(argv[2]));
if(connect(mysock,(struct sockaddr *) &servaddr, len) < 0){
printf("connect error!\n");
return -1;
}
memset(mybuff,0,sizeof(mybuff));
printf("Client Send:");
gets(mybuff);
bytes = send(mysock, mybuff, strlen(mybuff), 0);
if( bytes>0 ){
memset(mybuff,0,sizeof(mybuff));
}
bytes = recv(mysock, mybuff, sizeof(mybuff), 0);
if (bytes>0)
{
printf("client recv:%s\n", mybuff);
memset(mybuff,0,sizeof(mybuff));
}
}</span>
<img src="https://img-blog.csdn.net/20140614171203453?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMzg4OTc1Mw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />