Description of problem: [BGP UDN pre-merge testing] it takes about 5 minutes for routes of previously advertised UDN to disappear after the UDN is unlabelled off networkSelector 

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:

1. While BGP is enabled and with default network is advertised, created 3 UDN namespaces, create one UDN in each UDN namespaces, UDNs among 3 UDN namespaces are not overlapping

2. Labelled first two UDNs (UDN1 and UDN2) with label app=udn, which matches the networkSelector in ra-udn.yaml

2.  applied ra-udn.yaml, and waited till it is in Accepted state

3.  Verified UDN1 and UDN2 were advertised, UDN3 were not advertised correctly

4.  Unlabelled UDN2 with app-, then watch UDN2's routes to disappear

$ date;oc get userdefinednetwork -A --show-labels
Thu Feb 20 17:40:29 EST 2025
NAMESPACE                                NAME                 AGE     LABELS
e2e-test-udn-networking-3x2s8udd-k8s62   layer3-udn-78339-2   2m19s   <none>
e2e-test-udn-networking-3x2s8udd-mqd8m   layer3-udn-78339-3   2m      <none>
e2e-test-udn-networking-3x2s8udd-sphgr   layer3-udn-78339-1   2m38s   app=udn

$date; ip route show | grep bgp
Thu Feb 20 17:40:33 EST 2025
10.128.0.0/23 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.128.2.0/23 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.129.0.0/23 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.129.2.0/23 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.130.0.0/23 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.130.2.0/23 via 192.168.111.47 dev offloadbm proto bgp metric 20 
10.131.0.0/23 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.131.2.0/23 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.0.0/24 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.150.1.0/24 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.150.2.0/24 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.150.3.0/24 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.150.4.0/24 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.5.0/24 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.150.6.0/24 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.150.7.0/24 via 192.168.111.47 dev offloadbm proto bgp metric 20 
20.150.0.0/24 via 192.168.111.23 dev offloadbm proto bgp metric 20 
20.150.1.0/24 via 192.168.111.47 dev offloadbm proto bgp metric 20 
20.150.2.0/24 via 192.168.111.21 dev offloadbm proto bgp metric 20 
20.150.3.0/24 via 192.168.111.24 dev offloadbm proto bgp metric 20 
20.150.4.0/24 via 192.168.111.20 dev offloadbm proto bgp metric 20 
20.150.5.0/24 via 192.168.111.22 dev offloadbm proto bgp metric 20 
20.150.6.0/24 via 192.168.111.25 dev offloadbm proto bgp metric 20 
20.150.7.0/24 via 192.168.111.40 dev offloadbm proto bgp metric 20 

$ date; ip -6 route show | grep bgp
Thu Feb 20 17:40:38 EST 2025
2010:100:200:1::/64 via fd2e:6f44:5dd8:c956::18 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:2::/64 via fd2e:6f44:5dd8:c956::16 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:3::/64 via fd2e:6f44:5dd8:c956::19 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:4::/64 via fd2e:6f44:5dd8:c956::15 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:5::/64 via fd2e:6f44:5dd8:c956::21 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:6::/64 via fd2e:6f44:5dd8:c956::14 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:7::/64 via fd2e:6f44:5dd8:c956::17 dev offloadbm proto bgp metric 20 pref medium
2010:100:200:8::/64 via fd2e:6f44:5dd8:c956::26 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:1::/64 via fd2e:6f44:5dd8:c956::17 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:2::/64 via fd2e:6f44:5dd8:c956::26 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:3::/64 via fd2e:6f44:5dd8:c956::15 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:4::/64 via fd2e:6f44:5dd8:c956::18 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:5::/64 via fd2e:6f44:5dd8:c956::14 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:6::/64 via fd2e:6f44:5dd8:c956::16 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:7::/64 via fd2e:6f44:5dd8:c956::19 dev offloadbm proto bgp metric 20 pref medium
2011:100:200:8::/64 via fd2e:6f44:5dd8:c956::21 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:1::/64 via fd2e:6f44:5dd8:c956::15 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:2::/64 via fd2e:6f44:5dd8:c956::14 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:3::/64 via fd2e:6f44:5dd8:c956::16 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:4::/64 via fd2e:6f44:5dd8:c956::18 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:5::/64 via fd2e:6f44:5dd8:c956::19 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:6::/64 via fd2e:6f44:5dd8:c956::17 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:7::/64 via fd2e:6f44:5dd8:c956::26 dev offloadbm proto bgp metric 20 pref medium
fd01:0:0:8::/64 via fd2e:6f44:5dd8:c956::21 dev offloadbm proto bgp metric 20 pref medium

.............

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$date; ip route show | grep bgp
Thu Feb 20 17:45:09 EST 2025
10.128.0.0/23 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.128.2.0/23 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.129.0.0/23 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.129.2.0/23 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.130.0.0/23 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.130.2.0/23 via 192.168.111.47 dev offloadbm proto bgp metric 20 
10.131.0.0/23 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.131.2.0/23 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.0.0/24 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.150.1.0/24 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.150.2.0/24 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.150.3.0/24 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.150.4.0/24 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.5.0/24 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.150.6.0/24 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.150.7.0/24 via 192.168.111.47 dev offloadbm proto bgp metric 20 
20.150.0.0/24 via 192.168.111.23 dev offloadbm proto bgp metric 20 
20.150.3.0/24 via 192.168.111.24 dev offloadbm proto bgp metric 20 
20.150.4.0/24 via 192.168.111.20 dev offloadbm proto bgp metric 20 
20.150.6.0/24 via 192.168.111.25 dev offloadbm proto bgp metric 20 

$date; ip route show | grep bgp
Thu Feb 20 17:45:16 EST 2025
10.128.0.0/23 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.128.2.0/23 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.129.0.0/23 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.129.2.0/23 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.130.0.0/23 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.130.2.0/23 via 192.168.111.47 dev offloadbm proto bgp metric 20 
10.131.0.0/23 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.131.2.0/23 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.0.0/24 via 192.168.111.24 dev offloadbm proto bgp metric 20 
10.150.1.0/24 via 192.168.111.22 dev offloadbm proto bgp metric 20 
10.150.2.0/24 via 192.168.111.25 dev offloadbm proto bgp metric 20 
10.150.3.0/24 via 192.168.111.21 dev offloadbm proto bgp metric 20 
10.150.4.0/24 via 192.168.111.40 dev offloadbm proto bgp metric 20 
10.150.5.0/24 via 192.168.111.20 dev offloadbm proto bgp metric 20 
10.150.6.0/24 via 192.168.111.23 dev offloadbm proto bgp metric 20 
10.150.7.0/24 via 192.168.111.47 dev offloadbm proto bgp metric 20 

Actual results:  It took about 5 minutes for UDN2's route to disappear

Expected results: It should shorter time to un-advertise UDN2

Additional info:

Please fill in the following template while reporting a bug and provide as much relevant information as possible. Doing so will give us the best chance to find a prompt resolution.

Affected Platforms:

Is it an

1. internal CI failure
2. customer issue / SD
3. internal RedHat testing failure

If it is an internal RedHat testing failure:

• Please share a kubeconfig or creds to a live cluster for the assignee to debug/troubleshoot along with reproducer steps (specially if it's a telco use case like ICNI, secondary bridges or BM+kubevirt).

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• Did it happen in different CI lanes? If so please provide links to multiple failures with the same error instance
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• If it's a connectivity issue,
• What is the srcNode, srcIP and srcNamespace and srcPodName?
• What is the dstNode, dstIP and dstNamespace and dstPodName?
• What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)

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  • If it is a connectivity issue:
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    • What is the dstNode, dstNamespace, dstPodName and dstPodIP?
    • What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)
    • Please provide the UTC timestamp networking outage window from must-gather
    • Please provide tcpdump pcaps taken during the outage filtered based on the above provided src/dst IPs
  • If it is not a connectivity issue:
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