Is it platform specific

generic

Importance or Severity

High

Description of the bug

fib/test_fib.py::test_ipinip_hash_negative[ipv6] fails when run on isolated-v6 topologies as the test constructs an IPinIP packet with an IPv4 outer header.

There appears to be two distinct issues to address here:

1. IPinIPHashTest.check_hash (in sonic-mgmt/ansible/roles/test/files/ptftests/py3/hash_test.py) needs to use an IPv6 outer header when the testbed is isolated-v6. This probably needs to be passed in from the caller of the ptf runner.
2. IPinIPHashTest.check_ipv6_route (in the same file as above) makes multiple assumptions that the outermost header of the IPinIP packet is an IPv4 header, including in calls to scapy.

This was verified using t0-isolated-v6-d16u16s2 but I do not believe this is topology-specific other than the fact that I was using an isolated-v6 testbed.

Steps to Reproduce

From within a sonic-mgmt container at /data/tests:

sudo ./run_tests.sh -a False -n <TESTBED> -x -u -c fib/test_fib.py::test_ipinip_hash_negative

Actual Behavior and Expected Behavior

The test should pass when run on isolated-v6 testbeds.

Relevant log output

Output of show version

Attach files (if any)

No response