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  1. XenServer Org
  2. XSO-858

Inbound L2 broadcasts failing for specific VLANs


    • Type: Bug
    • Status: Done (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 7.4
    • Fix Version/s: None
    • Component/s: Networking
    • Labels:
    • Environment:


      Inbound L2 broadcasts failing to specific VLANs. Specifically with DHCP. If VM IPs are set statically all networking functions as expected.

      Can see inbound broadcasts get all the way to the hypervisor but are never forwarded up to VMs on the effected VLANs.

      Some VLANs work without issue..

      Noticed the issue while deploying a new domain controller on this XS pool. Old domain controller runs on another XS 7 box. Attempted to migrate DHCP to the new domain controller. Testing with physical DHCP client can see DHCP discoveries hit the hypervisor (via tcpdump) but never see the broadcasts hit any VM on the troublesome VLANs..

      Tested VM DHCP client on the same hypervisor to the new domain controller works without issue.

      Tested VM DHCP client on the same hypervisor to the old domain controller. DHCP times out at boot of VM. Login and force DHCP via dhclient. VM finally gets an IP after ~ 1 minute and 19 seconds..

      Steps taken:

      Verify XS network configuration

      Verify L2 switch configuration

      Verify LAG LACP configuration

      Delete and re-create VLAN interfaces on XS

      Upgrade XS from 7.1 to 7.4

      Reboot servers and switches

      For further information review the forum post: https://discussions.citrix.com/topic/394860-inbound-dhcp-failing-for-specific-vlans/

      Please feel free to reach out to me.





            • Assignee:
              kernel-panic Marcus Peterson
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              • Created: