Linux-Basics-Complete-Course-With-Notes-Slides

TROUBLESHOOTING

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 bob-repo-01
Server:      192.168.1.100
Address:     192.168.1.100 #53

Non-authoritative answer:
Name: bob-repo-01
Address: 192.168.2.5

ping to check the connectivity.

[~]$ ping bob-repo-01
PING bob-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.
```
[bob-repo-01: ~]$ netstat -an | grep 80 | grep -i LISTEN
```

To bring up the interface up use below command.

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

iplink