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Network Boundaries


TranslationFor pending..various reasons, thin clients and the openthinclient Management Server may be connected to different networks or network segments.

    Individual thin clients are located at sites with their own network infrastructure Dedicated VLAN for thin clients

    PXE boot across network boundaries requires configuration.

    To initiate PXE boot, the ProxyDHCP service of the openthinclient Management Server sends the necessary boot information when it detects appropriate DHCP communication between the thin client and the DHCP server (detailed information can be found in the article openthinclient OS — Boot Process).

    UDP broadcasts form a crucial part of DHCP communication, and networks typically route these broadcasts only within the local VLAN. If the openthinclient Management Server runs on the same network as the DHCP server, it can detect the DHCP communication and respond with boot information.

    Approach 1: DHCP Relay

    To work around the issue described above, many routers offer the ability to forward broadcasts from one network to a server on another network.

    Depending on the router and specific feature set, this function is called DHCP Relay Agent, UDP Helper, IP Helper, or something similar. The specific configuration depends on the respective router.

    The ProxyDHCP service of the openthinclient Management Server should receive the following broadcasts:

      DHCP Discover DHCP Offer DHCP Request

      Ensure the thin clients receive this broadcast from the ProxyDHCP service of the openthinclient Management Server.

        DHCP Offer

        Approach 2: Manually configure DHCP options

        If Approach 1 is unavailable, configure the DHCP server to send the information required for PXE boot.

        Note that the DHCP server then controls the settings, so the "Start Options" on the thin client and the "Hardware Type" settings are bypassed.

        For PXE boot, the DHCP server must send additional options. The specific options depend on the capabilities and settings of the thin client:

        Legacy PXE

        Option 66: TFTP server name

        IP address of the openthinclient Management Server

        Option 67: Boot File Name

        /lpxelinux.0 (corresponds to the "Quick" boot method)

        or

        /pxelinux.0  (corresponds to the "Safe" boot method)

        UEFI-PXE

        Option 66: TFTP server name

        IP address of the openthinclient Management Server

        Option 67: Boot File Name

        syslinux64.efi (corresponds to the "Fast" boot method)

        or

        ipxe64.efi  (corresponds to the "Safe" boot method)

        UEFI-HTTP

        Option 67: Boot File Name

        http://<SERVER_IP>:8080/openthinclient/files/tftp/ipxe64.efi 

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