Description of PR

Summary:
Fixes # (issue)
This is cherry-pick PR for 202205 branch. Original PR #11677

This PR fixes issue #11460

Type of change

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

Back port request

• 201911
• 202012
• 202205
• 202305
• 202311

Approach

What is the motivation for this PR?

• For T2 Chassis(topo-t2), route/test_route_flap works fine, if the selected duthost has upstream T3 neighbors.
• Similarly, if the selected duthost has downstream T1 neighbors and if there is only one dut with T1 neighbors, test works fine too.
• But if the selected duthost has downstream T1 neighbors and if there are more than one dut with downstream neighbors, route/test_route_flap fails.

How did you do it?

• Fetch the 'neighbor type' (LeafRouter/SpineRouter/AZNGhub) based on the chosen dev_port from get_dev_port_and_route
• Get all the neighbors of same neighbor type and fetch the ptf receiving ports list based on the retrieved neighbors list.
• Pass the received ptf ports list to send_recv_ping_packet method for further testing.

How did you verify/test it?

• Ran route/test_route_flap test case on T2 Chassis with 'topo-t2' topology having 3-line cards with at least 2 cards having downstream T1 neighbors.

• Test passes.

  Before the PR change:

  Test fetches only the ptf receiving ports of the DUT under test. T1 neighbor routes are same in all downstream DUTs. ping packet gets forwarded to other T1 neighbor DUT's ports instead of the DUT ports under test.

  After the PR change:

  Test fetches all the ptf receiving ports of all of the DUTs which has same type of neighbors similar to dut under test. Due to this change, we are making sure ping packet is received on any of the DUTs' ptf ports having similar neighbors (T1/T3).

Any platform specific information?

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

Documentation