[route] Fix random loss of arp info in test_static_route_ecmp

[yaqiangz]

Description of PR

Summary:
Fixes # 6576

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 201911
• 202012
• 202205

Approach

What is the motivation for this PR?

Fix test_static_route_ecmp failed due to losing arp info after config reload.

How did you do it?

After config reload, run ping cmd.

How did you verify/test it?

Run test.

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[azure-pipelines]

The pre-commit check detected issues in the files touched by this pull request.
The detected issues may be old or new. For new issues, please try to fix them.

For old issues, it is not mandatory to fix them because they were not caused by this change. It is unfair to blame
author of this pull request. But if you can take extra effort to fix the old issues as well, that would be great!

Detailed pre-commit check results:
trim trailing whitespace.................................................Failed
- hook id: trailing-whitespace
- exit code: 1
- files were modified by this hook

Fixing tests/route/test_static_route.py

fix end of files.........................................................Passed
check yaml...........................................(no files to check)Skipped
check for added large files..............................................Passed
check python ast.........................................................Passed
flake8...................................................................Failed
- hook id: flake8
- exit code: 1

tests/route/test_static_route.py:10:1: F401 'tests.common.fixtures.ptfhost_utils.change_mac_addresses' imported but unused
tests/route/test_static_route.py:10:1: F401 'tests.common.fixtures.ptfhost_utils.copy_arp_responder_py' imported but unused
tests/route/test_static_route.py:13:1: F401 'tests.common.dualtor.mux_simulator_control.mux_server_url' imported but unused
tests/route/test_static_route.py:14:1: F401 'tests.common.dualtor.mux_simulator_control.toggle_all_simulator_ports_to_rand_selected_tor_m' imported but unused
tests/route/test_static_route.py:21:1: F401 'tests.flow_counter.flow_counter_utils.is_route_flow_counter_supported' imported but unused
...
[truncated extra lines, please run pre-commit locally to view full check results]

To run the pre-commit checks locally, you can follow below steps:

1. Ensure that default python is python3. In sonic-mgmt docker container, default python is python2. You can run
   the check by activating the python3 virtual environment in sonic-mgmt docker container or outside of sonic-mgmt
   docker container.
2. Ensure that the pre-commit package is installed:

sudo pip install pre-commit

3. Go to repository root folder
4. Install the pre-commit hooks:

pre-commit install

5. Use pre-commit to check staged file:

pre-commit

6. Alternatively, you can check committed files using:

pre-commit run --from-ref <commit_id> --to-ref <commit_id>

[lgtm-com]

This pull request introduces 1 alert when merging 9c3bef9 into 04f0a29 - view on LGTM.com

new alerts:

• 1 for Unused local variable

[azure-pipelines]

The pre-commit check detected issues in the files touched by this pull request.
The detected issues may be old or new. For new issues, please try to fix them.

For old issues, it is not mandatory to fix them because they were not caused by this change. It is unfair to blame
author of this pull request. But if you can take extra effort to fix the old issues as well, that would be great!

Detailed pre-commit check results:
trim trailing whitespace.................................................Failed
- hook id: trailing-whitespace
- exit code: 1
- files were modified by this hook

Fixing tests/route/test_static_route.py

fix end of files.........................................................Passed
check yaml...........................................(no files to check)Skipped
check for added large files..............................................Passed
check python ast.........................................................Passed
flake8...................................................................Failed
- hook id: flake8
- exit code: 1

tests/route/test_static_route.py:10:1: F401 'tests.common.fixtures.ptfhost_utils.change_mac_addresses' imported but unused
tests/route/test_static_route.py:10:1: F401 'tests.common.fixtures.ptfhost_utils.copy_arp_responder_py' imported but unused
tests/route/test_static_route.py:13:1: F401 'tests.common.dualtor.mux_simulator_control.mux_server_url' imported but unused
tests/route/test_static_route.py:14:1: F401 'tests.common.dualtor.mux_simulator_control.toggle_all_simulator_ports_to_rand_selected_tor_m' imported but unused
tests/route/test_static_route.py:21:1: F401 'tests.flow_counter.flow_counter_utils.is_route_flow_counter_supported' imported but unused
...
[truncated extra lines, please run pre-commit locally to view full check results]

To run the pre-commit checks locally, you can follow below steps:

1. Ensure that default python is python3. In sonic-mgmt docker container, default python is python2. You can run
   the check by activating the python3 virtual environment in sonic-mgmt docker container or outside of sonic-mgmt
   docker container.
2. Ensure that the pre-commit package is installed:

sudo pip install pre-commit

3. Go to repository root folder
4. Install the pre-commit hooks:

pre-commit install

5. Use pre-commit to check staged file:

pre-commit

6. Alternatively, you can check committed files using:

pre-commit run --from-ref <commit_id> --to-ref <commit_id>