[Flaky e2e test] TestConnectivity/{testPingLargeMTU, testPodConnectivityDifferentNodes}

[hongliangl]

The e2e tests TestConnectivity/{testPingLargeMTU, testPodConnectivityDifferentNodes} are failing frequently for PRs #5159 #6312 on Windows e2e containerd test bed.

The following is the output of these two tests when got a failure:

=== RUN   TestConnectivity/testPodConnectivityDifferentNodes
    connectivity_test.go:76: Waiting for Pods to be ready and retrieving IPs
    connectivity_test.go:90: Retrieved all Pod IPs: map[connectivity-testdifferentnodes-bljwz:IPv4(192.168.1.37),IPstrings(192.168.1.37) connectivity-testdifferentnodes-lbm2k:IPv4(192.168.2.36),IPstrings(192.168.2.36)]
    connectivity_test.go:101: Ping mesh test between all Pods
    connectivity_test.go:116: Ping 'testconnectivity-f9r2j2o8/connectivity-testdifferentnodes-bljwz' -> 'testconnectivity-f9r2j2o8/connectivity-testdifferentnodes-lbm2k': ERROR (error when running ping command 'ping -c 5 -s 1422 -M do -4 192.168.2.36': command terminated with exit code 1 - stdout: PING 192.168.2.36 (192.168.2.36) 1422(1450) bytes of data.
        
        --- 192.168.2.36 ping statistics ---
        5 packets transmitted, 0 received, 100% packet loss, time 4092ms
        
         - stderr: )
    connectivity_test.go:118: Ping 'testconnectivity-f9r2j2o8/connectivity-testdifferentnodes-lbm2k' -> 'testconnectivity-f9r2j2o8/connectivity-testdifferentnodes-bljwz': OK
=== RUN   TestConnectivity/testPingLargeMTU
    connectivity_test.go:76: Waiting for Pods to be ready and retrieving IPs
    connectivity_test.go:90: Retrieved all Pod IPs: map[connectivity-testlargemtu-f2j9l:IPv4(192.168.1.38),IPstrings(192.168.1.38) connectivity-testlargemtu-hhqrl:IPv4(192.168.2.37),IPstrings(192.168.2.37) connectivity-testlargemtu-pcv7r:IPv4(192.168.0.52),IPstrings(192.168.0.52) connectivity-testlargemtu-spg58:IPv4(192.168.4.5),IPstrings(192.168.4.5)]
    connectivity_test.go:519: Running ping with size 2000 between Pods connectivity-testlargemtu-f2j9l and connectivity-testlargemtu-hhqrl
    connectivity_test.go:521: error when running ping command 'ping -c 5 -s 2000 -4 192.168.2.37': command terminated with exit code 1 - stdout: PING 192.168.2.37 (192.168.2.37) 2000(2028) bytes of data.
        
        --- 192.168.2.37 ping statistics ---
        5 packets transmitted, 0 received, 100% packet loss, time 4088ms
        
         - stderr: