• The Story of the PING Program

debian# apt install iputils-ping

$ ping 1.1.1.1

$ ping -f gate.isp.un

$ ping -i 0.1 gate.isp.un

$ ping -c 1 -D -s 1472 ya.ru

freebsd_sh$ ip=172.16.1.123; ping -c 1 -W 500  $ip >/dev/null ; arp -an | grep "$ip "

linux$ ip=172.16.1.254; ping -c 1 -W 1  $ip >/dev/null ; ip n | grep "$ip "

linux# tcpdump	-i any -n

tcpdump	-vn

tcpdump	-i em0 -n -s0 -A "port 21 and host 172.16.1.X"

tcpdump	-nei em0 ether src 00:0c:29:c5:07:8f

tcpdump	-w file.pcap -s0 "port 21 and host 172.16.1.X"

tcpdump	-n -r file.pcap -s0 -A

tcpdump	-n ip and 'ip[8]=127'   # ttl

#https://unix.stackexchange.com/questions/466584/tcpdump-tshark-view-only-outgoing-tcp-connections-requests
server# tcpdump -i any -nn src host 192.168.X.10 and "tcp[tcpflags] == tcp-syn"

traceroute -n ya.ru

tracepath -n ya.ru

• Утилиты тестирования DNS

• ttcp (Test TCP)

• Утилита iPerf