RHCSA Rapid Track
Course update
An updated version of this course is available that uses a newer version of Red Hat Enterprise Linux in the lab environment. Therefore, the RHEL 9.0 version of the lab environment will retire on December 31, 2024. Please complete any work in this lab environment before it is removed on December 31, 2024. For the most up-to-date version of this course, we recommend moving to the RHEL 9.3 version.
In this exercise, you inspect the network configuration of one of your servers.
Outcomes
Identify the current network interfaces and network addresses.
As the student user on the workstation machine, use the lab command to prepare your system for this exercise.
This command prepares your environment and ensures that all required resources are available.
[student@workstation ~]$ lab start net-validate
Instructions
Use the
sshcommand to log in toserveraas thestudentuser. The systems are configured to use SSH keys for authentication and passwordless access toservera.[student@workstation ~]$
ssh student@servera...output omitted... [student@servera ~]$Locate the network interface name that is associated with the
52:54:00:00:fa:0aEthernet address. Record or remember this name and use it to replace theenplaceholder in subsequent commands.XImportant
Network interface names are determined by their bus type and the detection order of devices during boot. Your network interface names vary according to the course platform and hardware in use.
On your system, locate the interface name (such as
ens06oren1p2) that is associated with the52:54:00:00:fa:0aEthernet address. Use this interface name to replace theenplaceholder that is used throughout this exercise.X[student@servera ~]$
ip link1: 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 2:en: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/etherX52:54:00:00:fa:0abrd ff:ff:ff:ff:ff:ffDisplay the current IP address and netmask for all interfaces.
[student@servera ~]$
ip -br addrlo UP 127.0.0.1/8 ::1/128en: UP 172.25.250.10/24 fe80::3059:5462:198:58b2/64XDisplay the statistics for the
eninterface.X[student@servera ~]$
ip -s link show en2:Xen: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:00:fa:0a brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped overrun mcast 89014225 168251 0 154418 0 0 TX: bytes packets errors dropped carrier collsns 608808 6090 0 0 0 0XDisplay the route information.
[student@servera ~]$
ip routedefault via 172.25.250.254 dev enXproto static metric 100 172.25.250.0/24 dev enXproto kernel scope link src 172.25.250.10 metric 100Verify that the router is accessible.
[student@servera ~]$
ping -c3 172.25.250.254PING 172.25.250.254 (172.25.250.254) 56(84) bytes of data. 64 bytes from 172.25.250.254: icmp_seq=1 ttl=64 time=0.196 ms 64 bytes from 172.25.250.254: icmp_seq=2 ttl=64 time=0.436 ms 64 bytes from 172.25.250.254: icmp_seq=3 ttl=64 time=0.361 ms --- 172.25.250.254 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 49ms rtt min/avg/max/mdev = 0.196/0.331/0.436/0.100 msShow all the hops between the local system and the
classroom.example.comsystem.[student@servera ~]$
tracepath classroom.example.com1?: [LOCALHOST] pmtu 1500 1: bastion.lab.example.com 0.337ms 1: bastion.lab.example.com 0.122ms 2: 172.25.254.254 0.602ms reached Resume: pmtu 1500 hops 2 back 2Display the listening TCP sockets on the local system.
[student@servera ~]$
ss -ltState Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 0.0.0.0:sunrpc 0.0.0.0:* LISTEN 0 128 0.0.0.0:ssh 0.0.0.0:* LISTEN 0 128 [::]:sunrpc [::]:* LISTEN 0 128 [::]:ssh [::]:*Return to the
workstationsystem as thestudentuser.[student@servera ~]$
exitlogout Connection to servera closed. [student@workstation ~]$
This concludes the section.