Guided Exercise: Edit Network Configuration Files - RHCSA 1

[Sanjeeth]

Verify that the new IP address is active.

[root@serverb ~]# ip -br addr show ens4 ens4 UP 172.24.250.40/24 10.0.1.2/24 fe80::5054:ff:fe01:fa28/64

[root@serverb ~]# ping -c3 10.0.1.1 PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data. 64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=1.25 ms 64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=0.483 ms 64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.413 ms --- 10.0.1.1 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2056ms rtt min/avg/max/mdev = 0.413/0.715/1.250/0.379 ms

 Address is set to 10.0.1.1 on servera and ping check is on 10.0.1.2. why?
Either way ping fails on serverb.

[root@servera system-connections]# ip -br addr show ens4
ens4 UP 172.24.250.30/16 10.0.1.1/8 fe80::5054:ff:fe01:fa1e/64

[student@serverb ~]$ ping -c3 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
^C
--- 10.0.1.1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2030ms

[student@serverb ~]$ ping -c3 172.24.250.30
PING 172.24.250.30 (172.24.250.30) 56(84) bytes of data.
^C
--- 172.24.250.30 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1036ms

[student@serverb ~]$ ping -c3 10.0.1.2
PING 10.0.1.2 (10.0.1.2) 56(84) bytes of data.
^C
--- 10.0.1.2 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1014ms

[student@serverb ~]$

[TudorRaduta]

hi - are the respective interfaces up?

[Sanjeeth]

I have attached screenshot of the interfaces in my post and yes they are up. Ignore the hostname though. Interface was setup on servera

reposting it here again:
[root@servera ~]# ip -br addr show ens4
ens4 UP 172.24.250.30/16 10.0.1.1/8 fe80::5054:ff:fe01:fa1e/64

ping is through on ens3

[root@servera ~]# ip -br addr show ens3
ens3 UP 172.25.250.10/24 fe80::5054:ff:fe00:fa0a/64
[root@servera ~]#

[student@serverb ~]$ ping 172.25.250.10
PING 172.25.250.10 (172.25.250.10) 56(84) bytes of data.
64 bytes from 172.25.250.10: icmp_seq=1 ttl=64 time=0.388 ms
64 bytes from 172.25.250.10: icmp_seq=2 ttl=64 time=0.375 ms
^C
--- 172.25.250.10 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1033ms
rtt min/avg/max/mdev = 0.375/0.381/0.388/0.006 ms
[student@serverb ~]$

[TudorRaduta]

I spotted your netmask is wrong as you've got 172.24.250.30/16 10.0.1.1/8 and it should be 172.24.250.30/24 10.0.1.1/24.

I might suggest to use the nmtui command to configure the servers as per the requirements of the exercise, I find it simpler and quicker

[Sanjeeth]

Thanks for the suggestion. I always use nmtui.

I have changed the subnet mask to /24 but the issue is the same as before

[root@servera ~]# ip -br addr show ens4
ens4 UP 172.24.250.30/24 10.0.1.1/24 fe80::5054:ff:fe01:fa1e/64
[root@servera ~]# exit

[student@serverb ~]$ ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
^C
--- 10.0.1.1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2033ms

[student@serverb ~]$ ping 172.24.250.30
PING 172.24.250.30 (172.24.250.30) 56(84) bytes of data.
^C
--- 172.24.250.30 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2083ms

[student@serverb ~]$

Secondly, in the guided exercise part of Red Hat Training I guess the IP is mentioned incorrectly

Posting it here for reference:
this is part of Chapter 18.4 in RHCSA 1

1. 1. Verify that the new IP address is active.

      [root@serverb ~]# ip -br addr show ens4 ens4 UP 172.24.250.40/24 10.0.1.2/24 fe80::5054:ff:fe01:fa28/64

2. Test connectivity between the servera and serverb machines by using the new network addresses. Ping the new address of the servera machine.

   [root@serverb ~]# ping -c3 10.0.1.1 PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data. 64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=1.25 ms 64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=0.483 ms 64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.413 ms

[Priyanshu20041]

The ping failure is caused by a subnet mask mismatch between servera and serverb.

On servera, the IP addresses are configured with larger subnet masks 10.0.1.1/8 and  172.24.250.30/16 , while on serverb the same networks are configured with /24 subnet masks  10.0.1.2/24 and 172.24.250.40/24. Due to this mismatch, both systems interpret the network ranges differently, which leads to ARP resolution failure and unsuccessful ICMP communication.

Suggestion:
Configure identical subnet masks on both servers for the same networks (for example, use /24 on both systems), then restart the network connection to ensure consistent routing and restore connectivity.

[Sanjeeth]

Unfortunately is of no help

[root@servera ~]# ip -br addr show ens4
ens4 UP 172.24.250.30/24 10.0.1.1/24 fe80::5054:ff:fe01:fa1e/64
[root@servera ~]# exit

[student@serverb ~]$ ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
^C
--- 10.0.1.1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2033ms

[student@serverb ~]$ ping 172.24.250.30
PING 172.24.250.30 (172.24.250.30) 56(84) bytes of data.
^C
--- 172.24.250.30 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2083ms

[student@serverb ~]$

[TudorRaduta · Accepted solution]

what is the IP configuration of serverb? 

According to the exercise we should have: 
ServerA - 172.24.250.30/24 and 10.0.1.1/24 configured on ens4 called "Wired Connection 1"
ServerB - 172.24.250.40/24 and 10.0.1.2/24 configured on ens4 called "Wired Connection 1"

I have redone the exercise according to the instructions and I am able to get ping replies as per the guide. 

[Sanjeeth]

Wired connection Profile was missing on serverb and after creating this I am able to ping the IP.

[root@serverb ~]# ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=1.16 ms
64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=0.328 ms
64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.502 ms
64 bytes from 10.0.1.1: icmp_seq=4 ttl=64 time=0.755 ms
^C
--- 10.0.1.1 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3068ms
rtt min/avg/max/mdev = 0.328/0.685/1.155/0.310 ms
[root@serverb ~]# ping 10.0.1.2
PING 10.0.1.2 (10.0.1.2) 56(84) bytes of data.
64 bytes from 10.0.1.2: icmp_seq=1 ttl=64 time=0.077 ms
64 bytes from 10.0.1.2: icmp_seq=2 ttl=64 time=0.071 ms
64 bytes from 10.0.1.2: icmp_seq=3 ttl=64 time=0.057 ms
^C
--- 10.0.1.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2048ms
rtt min/avg/max/mdev = 0.057/0.068/0.077/0.008 ms

Thank you for your inputs