ansible-role-connectivity-test

This role uses nc (netcat) to check for network problems to a given IP address and port (using TCP or UDP). It automatically selects the source IP based on the destination IP from the available network routes.

By default, it uses the TCP protocol. If you need to test with UDP, set protocol: udp.

Supported Distributions

• Ubuntu 18.04 / 16.04
• CentOS / RHEL: 7.x, 6.5, 5.9

Requirements

The following system commands are needed:

• nc (netcat) - will be installed if not already present
• ip
• awk

Default Configuration

• Debug mode

debug_enabled_default: false

• Time to wait before timing out

connectivity_test_wait_default: 5

• For using UDP if specified in configuration

connectivity_test_udp_command: "-u"

• Proxy settings

proxy_env: []

Example Configuration File (group_vars/xxx/connectivity-test-vars.yml)

TCP is the default protocol (no need to specify).

---
connectivity_test_destinations:
  - { ip: 192.168.56.10, port: 22 }
  - { ip: 192.168.56.10, port: 5000 }
  - { ip: 127.0.0.1, port: 53, protocol: udp }

Example Playbook connectivity-test.yml

---
- hosts: '{{inventory}}'
  become: yes
  roles:
  - connectivity-test

How to Run

ansible-playbook connectivity-test.yml --extra-vars "inventory=all-dev" -i hosts

To skip package installation (if you already know the packages are installed):

ansible-playbook connectivity-test.yml --extra-vars "inventory=all-dev" -i hosts --skip-tags connectivity_install_pkg

Sample Output

TASK [setup] *******************************************************************
ok: [centos7]

TASK [connectivity-test : Install necessary packages on RedHat systems] *
ok: [centos7] => (item=[u'nc'])

TASK [connectivity-test : Determine source IP based on destination IP] ***************
ok: [centos7] => (item=source ip: 127.0.0.1, destination ip: 127.0.0.1)
ok: [centos7] => (item=source ip: 127.0.0.1, destination ip: 127.0.0.1)
ok: [centos7] => (item=source ip: 192.168.56.9, destination ip: 192.168.56.10)

TASK [connectivity-test : debug] ***********************************************

TASK [connectivity-test : test network connectivity] ***************************
ok: [centos7] => (item=source ip: 192.168.56.9, destination ip: 192.168.56.10, port: 22, protocol: tcp, time: 2019-07-09 23:02:56.518272, stdout: SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.8, stderr: Connection to 192.168.56.10 22 port [tcp/ssh] succeeded!

)
ok: [centos7] => (item=source ip: 127.0.0.1, destination ip: 127.0.0.1, port: 53, protocol: udp, time: 2019-07-09 23:03:12.337049, stdout: , stderr: Connection to 127.0.0.1 53 port [udp/domain] succeeded!

)
failed: [centos7] (item=source ip: 192.168.56.9, destination ip: 192.168.56.10, port: 5000, protocol: tcp, time: 2019-07-09 23:03:33.893978, stdout: , stderr: nc: connect to 192.168.56.10 port 5000 (tcp) timed out: Operation now in progress

)

TASK [connectivity-test : debug] ***********************************************

PLAY RECAP *********************************************************************
centos7                    : ok=3    changed=0    unreachable=0    failed=1  

Manual Check

To manually test connectivity, you can use this command:

dIP="192.168.56.10 192.168.56.13";
dPORT="5000";
sIP=$(/sbin/ip route get "$(echo $dIP | awk -F" " 'NR==1{print $1}')" | awk 'NR==1{print $NF}');
uname -n;
echo "Source IP: $sIP";
for i in $dIP;
do date;
nc -v -w 3 -s "$sIP" "$i" "$dPORT";
echo " ";
done