iPerf: client pod failure on ipv6 traffic required for dual-stack cluster

[elenagerman]

Describe the bug
In the case of a dual-stack cluster, when ipv6 traffic is required, and even the '-6' option is provided, the 'iperf3 -c ' command will always use an ipv4 address.
The openshift preference in the case of dual-stack is always ipv4. And this is a reason the server pod will always have ipv4 as a main pod address (podIP value).

As a result, when '-6' option is used in this case and 'iperf3 -c ' will run to the ipv4 address, the pod execution fails.

To Reproduce
Steps to reproduce the behavior:

1. Deploy dual-stack cluster
2. apply this benchmark:
   `

apiVersion: ripsaw.cloudbulldozer.io/v1alpha1
kind: Benchmark
metadata:
name: iperf3-benchmark-iperf3
namespace: benchmark-operator
spec:
uuid: "3ac4f6c1-69f3-469d-aa9f-a81382a77007"
elasticsearch:
url: 'localhost'
clustername: kni-qe-3
metadata:
collection: true
privileged: true
serviceaccount: 'benchmark-operator'
targeted: false
workload:
name: iperf3
args:
image: "registry.kni-qe-3.lab.eng.rdu2.redhat.com:5000/cloud-bulldozer/iperf3:latest"
run_id: "100056"
pair: 1
port: 60001
transmit_type: time
transmit_value: 100
length_buffer: 500
streams: 1
extra_options_client: '-u -b 0 -6 -J -V'
pin: true
pin_server: "openshift-worker-3.kni-qe-3.lab.eng.rdu2.redhat.com"
pin_client: "openshift-worker-2.kni-qe-3.lab.eng.rdu2.redhat.com"

`
4. wait until client pod failure
5. oc describe client pod to see 'iperf3 -c addr' was used

Expected behavior
option to run iPerf ipv6 traffic on dual-stack cluster

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Additional context
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[elenagerman]

maybe possible solution: #815

[elenagerman]

Thanks a lot!