…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

Signed-off-by: Guy Shemesh <gshemesh@nvidia.com>

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

Signed-off-by: Lakshmi Yarramaneni <lakshmi@nexthop.ai>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by #20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Co-authored-by: vkjammala-arista <152394203+vkjammala-arista@users.noreply.github.com>

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

Signed-off-by: Yael Tzur <ytzur@nvidia.com>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: Yael Tzur <ytzur@nvidia.com>

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>

…) (sonic-net#22066)

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Co-authored-by: vkjammala-arista <152394203+vkjammala-arista@users.noreply.github.com>
Signed-off-by: Lakshmi Yarramaneni <lakshmi@nexthop.ai>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: nnelluri-cisco <nnelluri@cisco.com>

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

Signed-off-by: Raghavendran Ramanathan <rraghav@cisco.com>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: Raghavendran Ramanathan <rraghav@cisco.com>

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

Signed-off-by: Raghavendran Ramanathan <rraghav@cisco.com>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: Raghavendran Ramanathan <rraghav@cisco.com>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: Zhuohui Tan <zhuohui.tan@amd.com>

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>
Signed-off-by: Abhishek <abhishek@nexthop.ai>

On some platforms (e.g., S6100/202305), 'ip -stats neigh flush all'
fails with 'Failed to send flush request: No such file or directory'.

Wrap clear_dut_arp_cache() calls in try/except to handle this error
gracefully, matching the approach in PR sonic-net#20932 on master.

Tested on S6100 (tbtk5-t0-s6100-4, 202305 image):
- Before: FAILED with RunAnsibleModuleFail on neigh flush
- After: PASSED (1 passed in 434.67s)

Signed-off-by: Zhaohui Sun <zhaohuisun@microsoft.com>

On some platforms (e.g., S6100/202305), 'ip -stats neigh flush all'
fails with 'Failed to send flush request: No such file or directory'.

Wrap clear_dut_arp_cache() calls in try/except to handle this error
gracefully, matching the approach in PR sonic-net#20932 on master.

Tested on S6100 (tbtk5-t0-s6100-4, 202305 image):
- Before: FAILED with RunAnsibleModuleFail on neigh flush
- After: PASSED (1 passed in 434.67s)

Signed-off-by: Zhaohui Sun <zhaohuisun@microsoft.com>

On some platforms (e.g., S6100/202305), 'ip -stats neigh flush all'
fails with 'Failed to send flush request: No such file or directory'.

Wrap clear_dut_arp_cache() calls in try/except to handle this error
gracefully, matching the approach in PR #20932 on master.

Tested on S6100 (tbtk5-t0-s6100-4, 202305 image):
- Before: FAILED with RunAnsibleModuleFail on neigh flush
- After: PASSED (1 passed in 434.67s)

Signed-off-by: Zhaohui Sun <zhaohuisun@microsoft.com>

```
*   d849917 (HEAD -> user/r12f/merge-202412, origin/user/r12f/merge-202412, internal-202412) r12f 260209:0619 - Merge remote-tracking branch 'azure/202412' into internal-202412
|\
| * c4c429c (azure/202412) mssonicbld 260209:0115 - [action] [PR:21843] Fix test_bgp_suppress_fib.py flakiness on scale topos (sonic-net#1011)
| * 46503f1 Mark Xiao 260205:1058 - [202412] Fix test_acl.py [ipv6-ingress-uplink->downlink-*] cases for v6 topo (sonic-net#942)
| * b6c58d4 mssonicbld 260130:1215 - [action] [PR:21772] Fix test_bgp_suppress_fib.py for v6 topos (sonic-net#985)
| * e762451 mssonicbld 260130:1016 - [action] [PR:21762] Fix test_disk_exhaustion.py for v6 topos (sonic-net#983)
| * 02cadbb mssonicbld 260130:1016 - [action] [PR:21771] Fix test_bgp_bounce.py for v6 topos (sonic-net#984)
| * 7eab3e7 Priyansh 260129:1437 - [202412] Fix/nonlinear dataplane downtime (sonic-net#982)
| * de89a46 mssonicbld 260130:0616 - [action] [PR:21143] configlet/test_add_rack.py Add comparison ignore for extra entries added by generic patcher (sonic-net#977)
| * c731442 mssonicbld 260130:0616 - [action] [PR:21647] Remove test_route_flow_counter.py xfail for v6 topos (sonic-net#979)
| * 0ff3ecc mssonicbld 260130:0116 - [action] [PR:21717] [BGP][test_bgp_session.py::test_bgp_session_interface_down] - Increase BGP Session State Timeout Window when restarting SWSS Container (sonic-net#978)
| * e0a408c Mark Xiao 260129:0914 - [202412] Fix fib/test_fib.py test_vxlan_hash [ipv6-*] (sonic-net#971)
| * 51b0525 mssonicbld 260124:0615 - [action] [PR:21523] Feature/route programming data (sonic-net#974)
| * 2bb2a53 mssonicbld 260124:0615 - [action] [PR:21939] Fix/nonlinear high nexthop dataplane downtime (sonic-net#975)
| * 1fe73bc Mark Xiao 260123:1323 - [202412] Fix setup_interfaces fixture and related bgp tests for v6 topo (sonic-net#941)
| * fda4ac2 Chuan Wu 260124:0520 - Enhance PTF function at scale testbed (sonic-net#913)
| * e8edcae gshemesh2 260123:2317 - Manual cherry-pick PR: Adjust test_bgpmon.py to handle running over ipv6 only topologies sonic-net#21377 (sonic-net#888)
| * 24b3dc7 gshemesh2 260123:2313 - Manual cherry-pick of PR: Adjusting test_stress_arp is it can handle cases of ipv6-only topologies . sonic-net#20932 (sonic-net#923)
```

----
#### AI description  (iteration 1)
#### PR Classification
This pull request is a feature enhancement that adds and refines IPv6 compatibility across multiple BGP, ACL, and related test modules.

#### PR Summary
The changes extend the testing framework and helper utilities to support IPv6-only and dual-stack environments by conditionally switching commands, packet generation, and route verifications.
- `tests/bgp/test_bgpmon.py` and `tests/bgp/test_bgp_update_timer.py`: Updated function signatures and logic to construct, verify, and clean up IPv6 routes and packets (e.g., using /64 and /128 prefixes).
- `tests/bgp/test_bgp_suppress_fib.py` and `tests/bgp/test_bgp_peer_shutdown.py`: Modified commands and packet filters to support IPv6 addressing and proper neighbor session handling.
- `tests/common/...` files and generators: Integr...

…ies . (sonic-net#20932)

In IPv6-only topologies, use 'ip -6 neigh flush all' insted of 'ip -stats neigh flush all' to make it more focus on IPv6 only, and reduce the chance of unsuccessful execution of a command.

Add skip for test_ipv4_arp in case of ipv6 only topology.

1) Use "enum_rand_one_per_hwsku_frontend_hostname" for "test_ipv6_nd_incomplete"
   to select the duthost (as being used by other config fixtures like "config_facts",
   "ip_and_intf_info" etc). [Test was updated recently in PR20780 to use
   "enum_rand_one_per_hwsku_frontend_hostname" fixture but it seems mistakenly
   reverted by sonic-net#20932]

2) Most of testcases are sending protocol packets (arp, ipv6_echo requests etc) from
   server towards ToR device. On dualtor, these protocol packets will be processed by
   both the ToR duts and thus NEIGH_TABLE in APPL_DB will be populated in both the
   duts (though hardware/ASIC_DB programming will happen only on active ToR).

   Fix: It's always better to clear arp and fdb tables on both the ToRs before and
   after the testcase by updating "arp_cache_fdb_cleanup" fixture to iterate over
   "duthosts" for cleanup.

Signed-off-by: Vinod <vkjammala@arista.com>