04-Troubleshooting.md

TROUBLESHOOTING

• • Take me to the Tutorial

• In this lecture we will be going to troubleshooting the issue that Bob is facing.

• Bob is not able to reach to the repository server and he get the error as show below.

  

Check Interfaces

• Use the ip link to ensure the primary interface is up.

• In this case, the network interface named enp1s0f1 state is up.

  [~]$ ip link
  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc
      noqueue state UNKNOWN mode DEFAULT group default qlen 1000
      link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  2: enp1s0f1: <BROADCAST,BROADCAST,MULTICAST,UP> mtu 1500 qdisc
      fq_codel state UP mode DEFAULT group default qlen 1000
      link/ether 08:97:98:6e:55:4d brd ff:ff:ff:ff:ff:ff
  

• Check if we can resolve the hostname to IP address via nslookup

  [~]$ nslookup caleston-repo-01
  Server:      192.168.1.100
  Address:     192.168.1.100 #53
  
  Non-authoritative answer:
  Name: caleston-repo-01
  Address: 192.168.2.5
  

• ping to check the connectivity.

  [~]$ ping caleston-repo-01
  PING caleston-repo-01 (192.168.2.5) 56(84) bytes of data.
  
  --- localhost ping statistics ---
  3 packets transmitted, 0 received, 100% packet loss, time 2034ms
  

• traceroute to check the number of hops between the source.

  [~]$ traceroute 192.168.2.5
  
  Tracing route to example.com [192.168.2.5]
  over a maximum of 30 hops:
  1 <1 ms <1 ms <1 ms 192.168.1.1
  2 <2 ms <1 ms <1 ms 192.168.2.1
  3 * * * Request timed out.
  

• To check the port status use netstat command and to use it along with port number use below command.

  [caleston-repo-01: ~]$ netstat -an | grep 80 | grep -i LISTEN
  

  

• To bring up the interface up use below command.

  [caleston-repo-01: ~]$ ip link set dev enp1s0f1 up