[root@centos7 temp]# host www.baidu.com
www.baidu.com is an alias for www.a.shifen.com.
www.a.shifen.com has address 61.135.169.121
www.a.shifen.com has address 61.135.169.125
4、dig DNS
dig和host命令的语法一致，但提供了更详细的信息和更多的选项：
[root@centos7 ~]# dig www.baidu.com
; <<>> DiG 9.9.4-RedHat-9.9.4-29.el7_2.2 <<>> www.baidu.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22125
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;www.baidu.com. IN A
;; ANSWER SECTION:
www.baidu.com. 113 IN CNAME www.a.shifen.com.
www.a.shifen.com. 113 IN A 61.135.169.125
www.a.shifen.com. 113 IN A 61.135.169.121
;; Query time: 2 msec
;; SERVER: 223.5.5.5#53(223.5.5.5)
;; WHEN: 四 11月 10 12:31:20 CST 2016
;; MSG SIZE rcvd: 90
[root@centos7 ~]#
[root@centos7 ~]# dig +nocmd www.baidu.com A +noall +answer
www.baidu.com. 252 IN CNAME www.a.shifen.com.
www.a.shifen.com. 252 IN A 61.135.169.125
www.a.shifen.com. 252 IN A 61.135.169.121
还可以用@server的方式指定DNS服务器：
[root@centos7 ~]# dig +noall +answer www.baidu.com A @8.8.8.8
www.baidu.com. 21 IN CNAME www.a.shifen.com.
www.a.shifen.com. 263 IN A 61.135.169.125
www.a.shifen.com. 263 IN A 61.135.169.121
[root@idc-v-71253 ~]# arp -a
? (10.0.1.1) at 68:8f:84:01:f1:ff [ether] on ens33
? (10.0.1.102) at 00:50:56:a4:18:9a [ether] on ens33
? (10.0.1.254) at 00:50:56:a4:a9:16 [ether] on ens33
? (10.0.1.10) at 00:50:56:a4:d2:e4 [ether] on ens33
? (10.0.1.104) at 00:50:56:a4:37:a7 [ether] on ens33
[root@centos7 ~]# ssh 10.0.1.253
The authenticity of host '10.0.1.253 (10.0.1.253)' can't be established.
ECDSA key fingerprint is 96:bd:a3:a7:87:09:1b:53:44:4c:9b:b9:5f:b2:97:89.
Are you sure you want to continue connecting (yes/no)? yes #这里输入yes
Warning: Permanently added '10.0.1.253' (ECDSA) to the list of known hosts.
[email protected]'s password: #这里输入密码
Last login: Fri Nov 11 09:04:01 2016 from 192.168.78.137
[root@idc-v-71253 ~]# #已登录
[root@centos7 ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): #回车
Enter passphrase (empty for no passphrase): #回车
Enter same passphrase again: #回车
Your identification has been saved in /root/.ssh/id_rsa. #私钥
Your public key has been saved in /root/.ssh/id_rsa.pub. #公钥
The key fingerprint is:
be:c3:d0:02:50:35:35:fe:60:d6:2f:26:96:f0:e1:e6 root@centos7
The key's randomart image is:
+--[ RSA 2048]----+
| ...o.o |
| . o o |
| . . * . |
| . * = . |
| . .S + . |
| o=.o . |
| +E |
| o. |
| .. |
+-----------------+
[root@centos7 ~]#
[root@centos7 ~]# ssh-copy-id 10.0.1.253
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
[email protected]'s password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '10.0.1.253'"
and check to make sure that only the key(s) you wanted were added.
[root@centos7 ~]#
注册
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