Lab
A Cloud Guru

Troubleshooting network issues

In this exercise, you will need to troubleshoot and resolve connectivity issues to a web server. *This course is not approved or sponsored by Red Hat.*

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Path Info

Level

Advanced

Duration

1h 30m

Published

Apr 04, 2019

Challenge

Verify Server1.
Verify Server1 is running Apache:
```
systemctl status httpd
```
Verify Apache is listening on port 80:
```
ss -lntp | grep 80
```
Verify the content can be accessed locally:
```
curl localhost
```
Verify the firewall is permitting port 80 traffic:
```
firewall-cmd --list-all
```
Permit inbound traffic to Apache:
```
firewall-cmd --permanent --add-service=http
```
Reload the firewall to pickup the change:
```
firewall-cmd --reload
```
Challenge

Verify Server2.
On Server2 (10.0.1.11)

Attempt to pull the web content from Server1 via hostname:
```
curl ip-10-0-1-10.ec2.internal
```
Attempt to pull the web content from Server1 via IP
```
curl 10.0.1.10
```
Check to see what DNS hosts are being used:
```
cat /etc/resolv.conf
```
Verify resolution via the specified host:
```
dig @10.0.0.2 ip-10-0-1-10.ec2.internal
```
Verify /etc/nsswitch.conf:
```
vim /etc/nsswitch.conf
```
Attempt to pull the web content from Server1 via hostname:
```
curl ip-10-0-1-10.ec2.internal
```
Ping ip-10-0-1-10.ec2.internal:
```
ping ip-10-0-1-10.ec2.internal
```
Review /etc/hosts:
```
vim /etc/hosts
```
Attempt to pull the web content from Server1 via hostname:
```
curl ip-10-0-1-10.ec2.internal
```
Install elinks:
```
yum install -y elinks
```
Use elinks to view the content:
```
links -dump http://ip-10-0-1-10.ec2.internal
```

Author

A Cloud Guru

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

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