Commit 6889d964f3 for frr
commit 6889d964f3fead8385ab834589290912aed11ec4
Author: Donald Sharp <sharpd@nvidia.com>
Date: Thu Sep 17 13:12:40 2026 -0400
tests: Fix of expected order of bfd shutdown.
The topotest expects that r2 sees the bfd session down
and initiate it to r1. This is not necessarily the case
there are three cases:
a) r1 sees the bfd down event first, initiates a bgp cease to r2
b) r2 sees the bfd down event first, initiates a bgp cease to r1
c) r1 and r2 both see the bfd down event and initiate a bgp cease
where the cease is ignored by the other side.
Modify the test to check that the session is down, and one of these
situations has happened.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
diff --git a/tests/topotests/bgp_bfd_down_cease_notification/test_bgp_strict_bfd_packet_loss.py b/tests/topotests/bgp_bfd_down_cease_notification/test_bgp_strict_bfd_packet_loss.py
index 74be23afbf..2c4aa0b7f3 100644
--- a/tests/topotests/bgp_bfd_down_cease_notification/test_bgp_strict_bfd_packet_loss.py
+++ b/tests/topotests/bgp_bfd_down_cease_notification/test_bgp_strict_bfd_packet_loss.py
@@ -71,7 +71,9 @@ def test_bgp_strict_bfd_packet_loss():
Test BGP with strict BFD when BFD packets are dropped by ACL (network failure).
This simulates a real network failure where BFD packets are lost.
- BFD should timeout, and BGP should tear down with Cease/BFD Down notification.
+ BFD should timeout, and both BGP sessions should go down. Either
+ side may initiate Cease/BFD Down, or both may; a side that did not
+ initiate must receive and process the notification.
"""
tgen = get_topogen()
@@ -123,22 +125,54 @@ def test_bgp_strict_bfd_packet_loss():
r1.run("iptables -A OUTPUT -p udp --dport 3784 -j DROP")
r1.run("iptables -A INPUT -p udp --sport 3784 -j DROP")
+ def _session_down(neigh):
+ return (
+ neigh.get("bgpState") != "Established"
+ and neigh.get("peerBfdInfo", {}).get("status") == "Down"
+ )
+
+ def _initiated_bfd_down(neigh):
+ return neigh.get("lastResetDueTo") == "BFD down initiated"
+
+ def _received_bfd_down(neigh):
+ return (
+ neigh.get("lastResetDueTo") == "BGP Notification received"
+ and neigh.get("lastNotificationReason") == "Cease/BFD Down"
+ )
+
def _bgp_bfd_down_after_packet_loss():
"""
- After BFD packets are blocked, BFD should timeout and go Down.
- BGP in strict mode should then tear down after hold-time expires.
+ After BFD packets are blocked, both sessions should go down.
+
+ Either side may expire the strict hold-timer first, or both may
+ expire together. All of these are valid:
+ - R1 initiates, R2 receives Cease/BFD Down
+ - R2 initiates, R1 receives Cease/BFD Down
+ - both initiate, neither needs to process a notification
+ A side that did not initiate must have received and processed
+ the peer's Cease/BFD Down.
"""
- output = json.loads(r2.vtysh_cmd("show ip bgp neighbor 192.168.255.1 json"))
- expected = {
- "192.168.255.1": {
- "bfdHoldTimerExpired": True,
- "lastResetDueTo": "BFD down initiated",
- "peerBfdInfo": {
- "status": "Down",
- },
- }
- }
- return topotest.json_cmp(output, expected)
+ r1n = json.loads(r1.vtysh_cmd("show ip bgp neighbor 192.168.255.2 json"))[
+ "192.168.255.2"
+ ]
+ r2n = json.loads(r2.vtysh_cmd("show ip bgp neighbor 192.168.255.1 json"))[
+ "192.168.255.1"
+ ]
+
+ if not _session_down(r1n) or not _session_down(r2n):
+ return "BGP session still up or BFD not Down"
+
+ r1_init = _initiated_bfd_down(r1n)
+ r2_init = _initiated_bfd_down(r2n)
+ if not r1_init and not r2_init:
+ return "neither side initiated BFD down"
+
+ if not r1_init and not _received_bfd_down(r1n):
+ return "R1 did not initiate and did not receive Cease/BFD Down"
+ if not r2_init and not _received_bfd_down(r2n):
+ return "R2 did not initiate and did not receive Cease/BFD Down"
+
+ return None
step("Check if BGP tears down after BFD timeout due to packet loss")
test_func = functools.partial(_bgp_bfd_down_after_packet_loss)
@@ -147,26 +181,6 @@ def test_bgp_strict_bfd_packet_loss():
_, result = topotest.run_and_expect(test_func, None, count=60, wait=1)
assert result is None, "Failed to see BGP tear down after BFD packet loss"
- def _bgp_cease_notification_on_r1():
- """
- R1 should also see the BGP session down and receive notification.
- """
- output = json.loads(r1.vtysh_cmd("show ip bgp neighbor 192.168.255.2 json"))
- expected = {
- "192.168.255.2": {
- "lastNotificationReason": "Cease/BFD Down",
- "peerBfdInfo": {
- "status": "Down",
- },
- }
- }
- return topotest.json_cmp(output, expected)
-
- step("Check if R1 received Cease/BFD Down notification")
- test_func = functools.partial(_bgp_cease_notification_on_r1)
- _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
- assert result is None, "Failed to see BGP Cease/BFD Down notification on R1"
-
# Cleanup: Remove iptables rules
step("Cleanup: Remove iptables rules")
r1.run("iptables -D OUTPUT -p udp --dport 3784 -j DROP")
@@ -176,4 +190,3 @@ def test_bgp_strict_bfd_packet_loss():
if __name__ == "__main__":
args = ["-s"] + sys.argv[1:]
sys.exit(pytest.main(args))
-