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_pre_'s avatar
Icon for Nimbostratus rankNimbostratus
Jan 08, 2021

Relaying netboot/bootp/DHCP traffic for VPN user

Is there any way we could relay DHCP/bootp traffic for VPN users?


We have Mac installed with parallels to run windows 10. While the MAC is in the office we have the ability to re-image the VM via netboot but with everyone working from home we have lost this ability.

5 Replies

  • Hello, can you give me more detail here? Would this not kill the VPN connection while the process is running (re-image)? Do you just need access to the clients VPN address given to it by APM?

  • _pre_'s avatar
    Icon for Nimbostratus rankNimbostratus

    Hi Dave, we are not re-imaging the host , but rather a VM inside of the host.


    The host have VPN configured and its always connected when the device is not on-prem.

    We can reboot / re-image VM inside of a host without affecting the host uptime or network connectivity.


    Sorry for not making this clear



    • Dave_W's avatar
      Icon for Employee rankEmployee

      So with the client connected via VPN (APM Network Access) I would think so. Typically for accessing remote VPN connected clients you want to go into the APM Network Access configuration and disable SNAT. This means the source of the traffic over the VPN would now be on of the IPs assigned to the client via the Network Access Lease Pool.


      Keep mind if this is a unique Lease Pool Address/Subnet (i.e. does not exist on your network) you would need to add routes on your network to send the traffic back to APM or if Lease Pool Address/Subnet addresses already exist on your network you would need to enable Proxy ARP in the APM Network Access configuration.

      • _pre_'s avatar
        Icon for Nimbostratus rankNimbostratus

        Hi Dave,

        Thanks in advance!

        SNAT is disabled and Proxy ARP is enabled and I can connect to the client IP assigned by APM ( see configuration below ).

        The question is can we relay broadcast traffic from the client to specific IP outside the APM network?

        Just to be more specific :

        When the VirtualMachine it send DHCPDISCOVER message on the network using the destination address

        How do we capture this broadcast message so that we can relay it to the appropriate server that lives on the other side of the tunnel?

        apm resource network-access vpn_profile {
            address-space-exclude-dns-name { }
            address-space-exclude-subnet { }
            address-space-include-subnet { }
            address-space-local-subnets-excluded true
            application-launch-warning false
            client-interface-speed 2147483648
            customization-group vpn_profile_resource_network_access_customization
            dns-enforce-search-order false
            dns-primary x.x.x.x
            dns-register-connection true
            dns-secondary x.x.x.x
            leasepool-name vpn-ict
            microsoft-network-server true
            optimized-app { }
            preserve-source-port-strict all
            provide-client-cert false
            proxy-arp true
            snat none
            split-tunneling true
            supported-ip-version ipv4
            sync-with-active-directory true
  • Hi,


    there is an iApp that might solve your issue, it will create a Virtual Server for you, that will relay DHCP traffic from inside the tunnel to your DHCP server in your datacenter. I've implemented it twice so far and it worked well. However I never tested with VMs inside VMware or Parallels...


    Take a look at this DevCentral article: APM-DHCP Access Policy Example and Detailed Instructions

    Does it look like it could help?