Linux Network troubleshooting

1) Check the physical layer physical layers

IP link is etho, see if the network card stat up, the IP link set eth0 up to the UP network card

or whether the Ifconfig eth0 can acquire IP

2) Check the data link layer

Did arp-n learn about Mac?

3) Network layer

Ping

Did Route-n learn how to route

Traceroute or Mtr-n 8.8.8.8

NETSTAT-ANL whether to monitor IP or ss-ant

Dig @dns Server Destination IP

#如果禁ping, you can use the Telnet test, the ping is the ICMP protocol, Telnet is the TCP IP protocol

4) Transport Layer Tansport layers

Netstat-anl whether the port is listening

Iptable-l whether the port was dropped or reject or ss-l

Linux Network troubleshooting