Linux基礎：ネットワークを利用するコマンド

host ホスト名 または IPアドレス

[user@rocky9 ~]$ host www.example.com
www.example.com is an alias for www.example.com-v4.edgesuite.net.
www.example.com-v4.edgesuite.net is an alias for a1422.dscr.akamai.net.
a1422.dscr.akamai.net has address 210.236.20.224
a1422.dscr.akamai.net has address 210.236.20.241
a1422.dscr.akamai.net has IPv6 address 2001:2a8:1:1005::d30c:e9e3
a1422.dscr.akamai.net has IPv6 address 2001:2a8:1:1005::d30c:e9cb

[user@rocky9 ~]$ host 210.236.20.224
224.20.236.210.in-addr.arpa domain name pointer a210-236-20-224.deploy.akamaitechnologies.com.

ssh [ユーザー名@]ホスト名 または IPアドレス

[user@rocky9 ~]$ ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 08:00:27:c0:dc:12 brd ff:ff:ff:ff:ff:ff
    inet 10.0.2.15/24 brd 10.0.2.255 scope global dynamic noprefixroute enp0s3
       valid_lft 84117sec preferred_lft 84117sec
    inet6 fd17:625c:f037:2:a00:27ff:fec0:dc12/64 scope global dynamic noprefixroute 
       valid_lft 86327sec preferred_lft 14327sec
    inet6 fe80::a00:27ff:fec0:dc12/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

[user@rocky9 ~]$ ssh tanaka@10.0.2.15
The authenticity of host '10.0.2.15 (10.0.2.15)' can't be established.
ED25519 key fingerprint is SHA256:3KyjmeBRL3cgR+ZI0UP/c374Rbg5yfoJFj44gxTlEIs.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '10.0.2.15' (ED25519) to the list of known hosts.
tanaka@10.0.2.15's password: 

This is the Z Shell configuration function for new users,
zsh-newuser-install.
You are seeing this message because you have no zsh startup files
(the files .zshenv, .zprofile, .zshrc, .zlogin in the directory
~).  This function can help you with a few settings that should
make your use of the shell easier.

You can:

(q)  Quit and do nothing.  The function will be run again next time.

(0)  Exit, creating the file ~/.zshrc containing just a comment.
     That will prevent this function being run again.

(1)  Continue to the main menu.

--- Type one of the keys in parentheses --- 

Aborting.
The function will be run again next time.  To prevent this, execute:
  touch ~/.zshrc
[tanaka@rocky9]~% exit

Connection to 10.0.2.15 closed.
[user@rocky9 ~]$ 

ping ホスト名 または IPアドレス

[user@rocky9 ~]$ ping -c 4 10.0.2.15
PING 10.0.2.15 (10.0.2.15) 56(84) bytes of data.
64 バイト応答 送信元 10.0.2.15: icmp_seq=1 ttl=64 時間=0.033ミリ秒
64 バイト応答 送信元 10.0.2.15: icmp_seq=2 ttl=64 時間=0.109ミリ秒
64 バイト応答 送信元 10.0.2.15: icmp_seq=3 ttl=64 時間=0.032ミリ秒
64 バイト応答 送信元 10.0.2.15: icmp_seq=4 ttl=64 時間=0.034ミリ秒

--- 10.0.2.15 ping 統計 ---
送信パケット数 4, 受信パケット数 4, 0% packet loss, time 3115ms
rtt min/avg/max/mdev = 0.032/0.052/0.109/0.032 ms