Linux网络服务之高速缓存实例解决，linux网络服务
Linux网络服务之高速缓存实例解决，linux网络服务
Linux网络服务之高速缓存实例解决
1.什么是DNS：
DNS：
概念：(Domain Name Server，域名服务器)是进行域名(domain name)和与之相对应的IP地址 (IP address)转换的服务器。DNS中保存了一张域名(domain name)和与之相对应的IP地址 (IP address)的表，以解析消息的域名。 域名是Internet上某一台计算机或计算机组的名称，用于在数据传输时标识计算机的电子方位(有时也指地理位置)。域名是由一串用点分隔的名字组成的，通常包含组织名，而且始终包括两到三个字母的后缀，以指明组织的类型或该域所在的国家或地区。
权威DNS：主机中本身就有
非权威DNS：你来问我，我去找
指定的IP为主机地址/etc/resolv.conf
本地解析文件/etc/hosts
回环接口lo：类似条件反射，本机问本机，回环接口快，对外接口为别人用apache
主配置文件 /etc/named.conf
高速缓存优点：减少网络延迟，降低带宽使用量
默认时间期限：8630s(1天)，过期后需要重新缓存
2.高速缓存实验模拟
(1)准备
[root@foundation103 ~]# yum repolist list //查看yum源信息
[root@foundation103 ~]# yum clean all //清除yum缓存
[root@foundation103 ~]# yum repolist list
Loaded plugins: langpacks
rhel_dvd | 4.1 kB 00:00
(1/2): rhel_dvd/group_gz | 134 kB 00:00
(2/2): rhel_dvd/primary_db | 3.4 MB 00:00
repolist: 0
(2)安装DNS服务
[root@foundation103 ~]# yum install bind.x86_64 -y //安装DNS服务
[root@foundation103 ~]# systemctl start named //启动服务之后/etc/rndc.key会生成
//启动DNS,则是校验码不够，需要在机子中敲击键盘
[root@foundation103 ~]# ls -l /etc/rndc.key
[root@foundation103 ~]# cat /etc/rndc.key //查看key
[root@foundation103 ~]# vim /etc/resolv.conf
[root@foundation103 ~]# cat /etc/services | grep domain //查看dns服务端口
domain 53/tcp # name-domain server
domain 53/udp
domaintime 9909/tcp # domaintime
domaintime 9909/udp # domaintime
[root@foundation103 ~]# firewall-cmd –list-all
public (default, active)
interfaces: eth0
sources:
services: dhcpv6-client ssh
ports:
masquerade: no
forward-ports:
icmp-blocks:
rich rules:
(3)在火墙中添加dns
[root@foundation103 ~]# firewall-cmd –permanent –add-service=dns
success
[root@foundation103 ~]# firewall-cmd –reload
success
[root@foundation103 ~]# cat /etc/services | grep domain //查看dns服务端口
domain 53/tcp # name-domain server
domain 53/udp
domaintime 9909/tcp # domaintime
domaintime 9909/udp # domaintime
[root@foundation103 ~]# firewall-cmd –list-all
public (default, active)
interfaces: eth0
sources:
services: dhcpv6-client dns ssh
ports:
masquerade: no
forward-ports:
icmp-blocks:
rich rules:
(4)实验
[root@foundation103 ~]# netstat -antlupe | grep 53 //查看，120端口添加了53
[root@foundation103 ~]# ifconfig
lo: flags=73
3.DNS服务器
.com .cn .edu .org .net 等等共13个 在美国斯科
noerror: 查询成功
nxdomain: 服务器不存在这样的名称
servfail: DNS服务器停机或响应失败
refused: DNS服务器拒绝回答
4.DNS正向解析
[root@foundation3 Desktop]# dig www.baidu.com
[root@foundation103 ~]# vim /etc/named.conf //查看子配置文件
57 include “/etc/named.rfc1912.zones”;
58 include “/etc/named.root.key”;
删除第18行forwarders { 172.25.254.250; };
[root@foundation103 ~]# vim /etc/named.rfc1912.zones //查看子配置文件
25 zone “westos.com” IN {
26 type master;
27 file “westos.com.zone”;
28 allow-update { none; };
29 };
[root@foundation103 ~]# cd /var/named
[root@foundation103 named]# cp -p named.localhost westos.com.zone //-p加权限
[root@foundation103 named]# vim westos.com.zone
$TTL 1D
@ IN SOA dns.westos.com. root.westos.com. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS dns.westos.com.
dns A 172.25.254.103
www AAAA 172.25.254.20
~
// @:westos.com，有.的意思就是结束了，没有‘.’就相当于在后面加上‘.westos.com.’
// 1D表示1天
// @表示westos.com //不是以.结尾的文件都会自动添加@符号
// SOA表示授权主机
// NS表示nameserver域名服务器名称 .表示结束
// AAAA：IPV6解析模式，A：IPV4解析模式
[root@foundation103 named]# systemctl restart named
真机中：
[root@foundation3 Desktop]# dig www.westos.com
;; ANSWER SECTION:
www.westos.com. 86400 IN A 172.25.254.20 //文件中解析出来ok
;; AUTHORITY SECTION:
westos.com. 86400 IN NS dns.westos.com.
;; ADDITIONAL SECTION:
dns.westos.com. 86400 IN A 172.25.254.103
5.DNS将客户访问的名称转化为内部的名称
[root@foundation3 Desktop]# dig www.baidu.com
;; ANSWER SECTION:
www.baidu.com. 901 IN CNAME www.a.shifen.com.
www.a.shifen.com. 1 IN A 220.181.111.188
www.a.shifen.com. 1 IN A 220.181.112.244
[root@foundation103 named]# vim westos.com.zone
NS dns.westos.com.
dns A 172.25.254.103
www CNAME bbs.westos.com.
bbs A 172.25.254.20
[root@foundation103 named]# systemctl restart named
[root@foundation3 Desktop]# dig www.westos.com
;; ANSWER SECTION:
www.westos.com. 86400 IN CNAME bbs.westos.com.
bbs.westos.com. 86400 IN A 172.25.254.20
6.DNS服务器的轮寻
[root@foundation3 Desktop]# dig www.baidu.com
;; ANSWER SECTION:
www.baidu.com. 901 IN CNAME www.a.shifen.com.
www.a.shifen.com. 1 IN A 220.181.111.188
www.a.shifen.com. 1 IN A 220.181.112.244
;; AUTHORITY SECTION:
a.shifen.com. 901 IN NS ns2.a.shifen.com.
a.shifen.com. 901 IN NS ns5.a.shifen.com.
a.shifen.com. 901 IN NS ns4.a.shifen.com.
a.shifen.com. 901 IN NS ns1.a.shifen.com.
a.shifen.com. 901 IN NS ns3.a.shifen.com.
//其中ns12345五台服务器轮寻服务
[root@foundation103 named]# vim westos.com.zone
NS dns.westos.com.
dns A 172.25.254.103
www CNAME bbs.westos.com.
bbs A 172.25.254.20
bbs A 172.25.254.120
[root@foundation103 named]# systemctl restart named
[root@foundation3 Desktop]# dig www.westos.com //查看
7.反向解析：指定IP解析出域名
[root@foundation103 named]# vim /etc/named.rfc1912.zones
48 zone “254.25.172.in-addr.arpa” IN {
49 type master;
50 file “westos.com.ptr”;
51 allow-update { none; };
52 };
[root@foundation103 named]# cp -p named.loopback westos.com.ptr
[root@foundation103 named]# vim westos.com.ptr
1 $TTL 1D
2 @ IN SOA dns.westos.com. root.westos.com. (
3 0 ; serial
4 1D ; refresh
5 1H ; retry
6 1W ; expire
7 3H ) ; minimum
8 NS dns.westos.com.
9 dns A 172.25.254.103
10 20 PTR www.westos.com.
11 120 PTR bbs.westos.com.
[root@foundation103 named]# systemctl restart named
[root@foundation3 Desktop]# dig -x 172.25.254.20 //-x反向解析
[root@foundation3 Desktop]# dig -x 172.25.254.120
排错：端口，网络，权限，配置文件
8.双向解析：
内网本机：企业内的主机 解析192 外网：企业外 解析172
[root@foundation103 ~]# cd /var/named/
[root@foundation103 named]# ls //查看目录
data named.empty slaves
dynamic named.localhost westos.com.ptr
named.ca named.loopback westos.com.zone
[root@foundation103 named]# cp westos.com.zone westos.com..zone.inter -p//复制文件
[root@foundation103 etc]# cd /etc/
[root@foundation103 etc]# cp named.rfc1912.zones named.rfc1912.zones.inter -p
[root@foundation103 etc]# vim named.rfc1912.zones.inter
25 zone “westos.com” IN {
26 type master;
27 file “westos.com.inter”;
28 allow-update { none; };
29 };
[root@foundation103 etc]# man 5 named.conf //查看命令
/view
[root@foundation103 etc]# vim named.conf //编辑配置文件
注释掉51-58行内容
59 view localnet {
60 match-clients { 172.25.254.103; }; //是103的ip用103机器进行解析
61 zone “.” IN{
62 type hint;
63 file “named.ca”;
64 };
65 include “/etc/named.rfc1912.zones.inter”;
66 };
67
68 view internet {
69 match-clients { any; };
70 zone “.” IN {
71 type hint;
72 file “named.ca”;
73 };
74 include “/etc/named.rfc1912.zones”;
75 };
[root@foundation103 named]# vim westos.com.zone.inter
$TTL 1D
@ IN SOA dns.westos.com. root.westos.com. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS dns.westos.com.
dns A 192.25.254.103
www CNAME bbs.westos.com.
bbs A 192.25.254.20
bbs A 192.25.254.120
[root@foundation103 etc]# systemctl restart named
真机和虚拟机同时[root@foundation103 etc]# dig www.westos.com
9.辅助DNS：
3 ：识别码，随便改
1D：刷新频率
1H：重连时间
1W：失效天数
3H：最短访问时间，第一次访问后，3小时内访问的内容一致
[root@server3 ~]# vim /etc/yum.repos.d/rhel_dvd.repo
[root@server3 ~]# yum clean all
[root@server3 ~]# yum install bind -y
[root@server3 ~]# vim /etc/named.conf
11 // listen-on port 53 { 127.0.0.1; }; ##//表示注释
12 // listen-on-v6 port 53 { ::1; };
17 // allow-query { localhost; };
[root@server3 ~]# vim /etc/named.rfc1912.zones
25 zone “westos.com” IN {
26 type slave;
27 masters { 172.25.254.103; };
28 file “slaves/westos.com.zone”;
29 allow-update { none; };
30 };
[root@server3 ~]# cd /var/named
[root@server3 named]# ls slaves/
[root@server3 named]# systemctl restart named //在虚拟机敲几下
[root@server3 named]# ls slaves/
westos.com.zone
[root@foundation103 named]# vim /etc/resolv.conf
nameserver 172.25.254.203
[root@foundation103 named]# vim westos.com.zone //改地址
[root@server3 named]# dig www.westos.com //查看
[root@foundation103 named]# vim /etc/named.rfc1912.zones
zone “westos.com” IN {
type master;
file “westos.com.zone”;
allow-update { none; };
also-notify { 172.25.254.203; };
};
[root@server3 named]# systemctl stop firewalld
[root@foundation103 named]# systemctl restart named
[root@foundation103 named]# systemctl restart named
[root@server3 named]# dig www.westos.com
;; ANSWER SECTION:
www.westos.com. 86400 IN CNAME bbs.westos.com.
bbs.westos.com. 86400 IN A 172.25.254.50
bbs.westos.com. 86400 IN A 172.25.254.220
[root@foundation103 named]# vim /etc/named.rfc1912.zones
zone “westos.com” IN {
type master;
file “westos.com.zone”;
allow-update { none; };
also-notify { 172.25.254.203; };
};
[root@server3 named]# systemctl stop firewalld
[root@foundation103 named]# vim /var/named/westos.com.zone
$TTL 1D
@ IN SOA dns.westos.com. root.westos.com. (
1 ; serial //1 ：识别码，随便改
1D ; refresh //1D：刷新频率
1H ; retry //1H：重连时间
1W ; expire //1W：失效天数
3H ) ; minimum
//3H：最短访问时间，第一次访问后，3小时内访问的内容一致
NS dns.westos.com.
dns A 172.25.254.103
www CNAME bbs.westos.com.
bbs A 172.25.254.50
bbs A 172.25.254.220
[root@server3 named]# dig www.westos.com
;; ANSWER SECTION:
www.westos.com. 86400 IN CNAME bbs.westos.com.
bbs.westos.com. 86400 IN A 172.25.254.50
bbs.westos.com. 86400 IN A 172.25.254.220
3H：最短访问时间，第一次访问后，3小时内访问的内容一致
10.DNS远程解析：
(1)准备
[root@foundation103 named]# cp -p westos.com.zone /mnt/
[root@foundation103 named]# ls /mnt/
westos.com.zone
(2)实验
[root@foundation103 named]# vim /etc/named.rfc1912.zones
28 allow-update { 172.25.254.203; };
[root@server3 named]# vim /etc/named.rfc1912.zones
[root@localhost ~]# vim /etc/named.conf
注释59到最后的所有行，恢复51-58行
[root@localhost ~]# systemctl restart named
[root@server3 named]# nsupdate
server 172.25.254.103
update add hello.westos.com 86400 A 172.25.254.120 //86400s A->Ipv4
send
update failed: REFUSED
[root@foundation103 named]# vim /var/log/messages
Feb 5 03:24:44 localhost named[2763]: client 172.25.254.203#24244: view internet: update ‘westos.com/IN’ denied //需要添加权限
[root@foundation103 named]# ls -ld
drwxr-x— 5 root named 4096 Feb 5 02:42
[root@foundation103 named]# chmod g+w /var/named/
[root@foundation103 named]# ls -ld
drwxrwx— 5 root named 4096 Feb 5 02:42
[root@foundation103 named]# > /var/log/messages
[root@server3 named]# nsupdate
update add hello.westos.com 86400 A 172.25.254.120
send
update failed: REFUSED //设置SELinux
[root@localhost ~]# setsebool -P named_write_master_zones 1
[root@server3 named]# nsupdate
update add hello.westos.com 86400 A 172.25.254.120
update add hello.westos.com 86400 A 172.25.254.122
send
[root@localhost ~]# vim /var/named/westos.com.zone
hello A 172.25.254.120
A 172.25.254.122
加密的更新
还原以前的备份
[root@localhost mnt]# cd /var/named/
[root@localhost named]# rm -fr westos.com.zone westos.com.zone.jnl
[root@localhost named]# cp -p /mnt/westos.com.zone /var/named/
[root@localhost named]# vim westos.com.zone //查看是否还原成功
[root@localhost named]# vim /etc/rndc.key //查看key的模板
key “rndc-key” {
algorithm hmac-md5;
secret “/W3/O/dH7EaKNJqqZwuxIQ==”;
};
[root@localhost named]# cp /etc/rndc.key /etc/westos.key //制作key
[root@localhost named]# dnssec-keygen –help //查看生成钥匙的帮助
[root@localhost named]# dnssec-keygen -a HMAC-MD5 -b 128 -n HOST westos
//-a加密方式 -b长度0-512 -n:HOST解析 westos名称
Kwestos.+157+14973 //在虚拟机中多敲几次
[root@localhost named]# ls
Kwestos.+157+14973.private
Kwestos.+157+14973.key
[root@localhost named]# cat Kwestos.+157+14973.private
Key: T3ltQ1Ypb8YNfQIeP61i6w== //密文
[root@localhost named]# cat Kwestos.+157+14973.key
westos. IN KEY 512 3 157 T3ltQ1Ypb8YNfQIeP61i6w== //密文
//二者密文相同—>md5加密方式为对称加密方式
[root@localhost named]# vim /etc/westos.key //更改加密文件
key “westos” {
algorithm hmac-md5;
secret “T3ltQ1Ypb8YNfQIeP61i6w==”;
};
[root@localhost named]# vim /etc/named.conf //更改配置文件
44 include “/etc/westos.key”;
[root@localhost named]# vim /etc/named.rfc1912.zones
28 allow-update { key westos; };
[root@localhost named]# systemctl restart named
[root@localhost named]# scp Kwestos.+157+14973.* root@172.25.254.203:/mnt/ //发密码
[root@server3 mnt]# nsupdate -k Kwestos.+157+14973.private
server 172.25.254.103
update add hello.westos.com 86400 A 172.25.254.9
send
quit
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