"Address family not supported by protocol" error for ping test in cflinuxfsv4 based application

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

This document explains how to perform ICMP (ping) tests in the cflinuxfsv4 based application.

If you perform a cf ssh you will be logged in as 'vcap' user, if you are running on cflinuxfsv4 the ping will fail with the following error:

Address family not supported by protocol

This was possible in cflinuxfsv3:



You can check which 'stack' (cflinuxfsv3 - cflinuxv4) you are running in the background if you issue the following command:

cf app <app_name>
 

user@#########.com ~ % cf app test-app
Showing health and status for app test-app in org system / space system as admin...

name:              test-app
requested state:   started
routes:            test-app.########.com
last uploaded:     Wed 28 Jun 16:47:44 CST 2023
stack:             cflinuxfs3
buildpacks:        go

type:           web
instances:      1/1
memory usage:   256M
     state     since                  cpu    memory          disk         details
#0   running   2023-06-28T22:47:56Z   0.4%   18.2M of 256M   8.8M of 1G   
[e-mail] ~ %

In order to change the stack you can check this document.

Workaround

The previous scenarios indicate the 'ping' test disabled for 'vcap' user in cflinuxfsv4 and limited to root user only.

You can still perform this test if you ssh as 'root' user via the container. You can follow this KB in order to ssh into the app/container as the root user.

Environment

Product Version: 3.0

Resolution

The following TAS releases contain the fix for this behavior:
 

• 3.0 -> TAS: 3.0.17, IST: 3.0.17
• 4.0 -> TAS: 4.0.9, IST: 4.0.9
• 5.0 -> TAS: 5.0.0, IST: 5.0.0