Description of problem:

 UDN pod cannot be accessed with BGP adverteised when the pod located node reboot.

# oc get ra cudn
NAME   STATUS
cudn   Accepted

# oc get pod -n blue -o wide
NAME            READY   STATUS    RESTARTS   AGE    IP            NODE       NOMINATED NODE   READINESS GATES
test-rc-f9vcq   1/1     Running   5          171m   10.128.2.18   worker-0   <none>           <none>
test-rc-mnscz   1/1     Running   0          171m   10.129.2.10   worker-2   <none>           <none>0 

# oc rsh -n blue test-rc-mnscz ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0@if20: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1400 qdisc noqueue state UP group default 
    link/ether 0a:58:0a:81:02:0a brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.129.2.10/23 brd 10.129.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::858:aff:fe81:20a/64 scope link 
       valid_lft forever preferred_lft forever
3: ovn-udn1@if21: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1400 qdisc noqueue state UP group default 
    link/ether 0a:58:14:64:04:05 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 20.100.4.5/24 brd 20.100.4.255 scope global ovn-udn1
       valid_lft forever preferred_lft forever
    inet6 fe80::858:14ff:fe64:405/64 scope link 
       valid_lft forever preferred_lft forever

# oc rsh -n blue test-rc-f9vcq ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0@if31: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1400 qdisc noqueue state UP group default 
    link/ether 0a:58:0a:80:02:12 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.128.2.18/23 brd 10.128.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::858:aff:fe80:212/64 scope link 
       valid_lft forever preferred_lft forever
3: ovn-udn1@if32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1400 qdisc noqueue state UP group default 
    link/ether 0a:58:14:64:00:05 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 20.100.0.5/24 brd 20.100.0.255 scope global ovn-udn1
       valid_lft forever preferred_lft forever
    inet6 fe80::858:14ff:fe64:5/64 scope link 
       valid_lft forever preferred_lft forever

#### after worker-0 is reboot and back to ready

#### pod (reboot node) cannot be accessed from another pod
# oc exec -n blue test-rc-mnscz -- curl 20.100.0.5:8080 --connect-timeout 2
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:--  0:00:02 --:--:--     0
curl: (28) Connection timeout after 2001 ms
command terminated with exit code 28

#### pod can be accessed from external router

# curl 20.100.0.5:8080
Hello OpenShift!

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

How reproducible:

Steps to Reproduce:

1. create cudn and namespace with test 2 pods to make them schedule 2 nodes
2. Create RA to advertised BGP
3. select one pod A node to reboot
4. after node back to ready
5. from pod B to access Pod A

Actual results:

podA cannot be access from podB

Expected results:

podA can be access from podB

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).

If it is a CI failure:

• Did it happen in different CI lanes? If so please provide links to multiple failures with the same error instance
• Did it happen in both sdn and ovn jobs? If so please provide links to multiple failures with the same error instance
• Did it happen in other platforms (e.g. aws, azure, gcp, baremetal etc) ? If so please provide links to multiple failures with the same error instance
• When did the failure start happening? Please provide the UTC timestamp of the networking outage window from a sample failure run
• 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)

If it is a customer / SD issue:

• Provide enough information in the bug description that Engineering doesn’t need to read the entire case history.
• Don’t presume that Engineering has access to Salesforce.
• Do presume that Engineering will access attachments through supportshell.
• Describe what each relevant attachment is intended to demonstrate (failed pods, log errors, OVS issues, etc).
• Referring to the attached must-gather, sosreport or other attachment, please provide the following details:
  • If the issue is in a customer namespace then provide a namespace inspect.
  • If it is a connectivity issue:
    • What is the srcNode, srcNamespace, srcPodName and srcPodIP?
    • 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:
    • Describe the steps taken so far to analyze the logs from networking components (cluster-network-operator, OVNK, SDN, openvswitch, ovs-configure etc) and the actual component where the issue was seen based on the attached must-gather. Please attach snippets of relevant logs around the window when problem has happened if any.

• When showing the results from commands, include the entire command in the output.  
• For OCPBUGS in which the issue has been identified, label with “sbr-triaged”
• For OCPBUGS in which the issue has not been identified and needs Engineering help for root cause, label with “sbr-untriaged”
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