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eferreira_FTNT
Staff
Staff
October 15, 2014
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FOS 5.2 transparent mode module

  • October 15, 2014
  • 1 reply
  • 4987 views
Hi, This is a recording of the first draft of the transparent mode module for FOS 5.2: https://www.brainshark.com/fortinet/vu?pi=zGJzT1BNYzJRhMz0 You are more than welcome to watch it and share your comments and feedback in the forum. Regards, Edy
    Best answer by ede_pfau

    Thanks for the preview.

    Some things where I stuck:

    You talk about "MAC addresses" often. I wonder why you avoid mentioning the OSI layer model, Layer 2 and 3.

     

    pg 4. NAT mode: "FortiGate ports have IP addresses." ...which certainly is not true - they don't need to have addresses. Rather, "Ports need to have unique IP addresses if any.".

    pg 5. It really would be enlightening if you could clarify whether a TP-mode FGT is a switch or a hub. All doc examples only show 2 ports active which doesn't allow this distinction to be made. Later on on pg. 6 you start talking about it being a bridge, then drop that in favor of "switch". As bridges are nearly extinct today I'd feel more comfortable with "switch".

    One property of a switch is that it will forward a packet only to the port which has previously seen the destination's MAC address. If the destination MAC is not yet known a switch has to broadcast an ARP request to all ports. So, eventually, a switch can also connect collision domains.

    "Forwarding domain" pg7-9: IMHO forwarding broadcasts from one VLAN to all ports is correct behavior as a VLAN has the explicit advantage NOT to tie VLAN members to one physical segment. I assume that's why this is the default way VLAN broadcasts work in FortiOS. You elaborate that this might have disadvantages in large networks which is a corner case in my opinion - connectivity before efficiency. At least, the student should not get the impression that without defining forwarding domains VLANs are not correctly set up.

    diag command: only 16 seconds are not sufficient to explain the data which you can obtain from the output, which is a pity. As we all know, diag command are essential, and essentially not undocumented.

     

    1 reply

    Mark_Oakton
    New Member
    October 16, 2014
    thanks, its usefule
    MatthewSabin
    New Member
    April 1, 2016

    Good overview. Thanks!

     

    I would like more detail in how to configure and troubleshoot.

    ede_pfau
    SuperUser
    ede_pfauAnswer
    SuperUser
    April 2, 2016

    Thanks for the preview.

    Some things where I stuck:

    You talk about "MAC addresses" often. I wonder why you avoid mentioning the OSI layer model, Layer 2 and 3.

     

    pg 4. NAT mode: "FortiGate ports have IP addresses." ...which certainly is not true - they don't need to have addresses. Rather, "Ports need to have unique IP addresses if any.".

    pg 5. It really would be enlightening if you could clarify whether a TP-mode FGT is a switch or a hub. All doc examples only show 2 ports active which doesn't allow this distinction to be made. Later on on pg. 6 you start talking about it being a bridge, then drop that in favor of "switch". As bridges are nearly extinct today I'd feel more comfortable with "switch".

    One property of a switch is that it will forward a packet only to the port which has previously seen the destination's MAC address. If the destination MAC is not yet known a switch has to broadcast an ARP request to all ports. So, eventually, a switch can also connect collision domains.

    "Forwarding domain" pg7-9: IMHO forwarding broadcasts from one VLAN to all ports is correct behavior as a VLAN has the explicit advantage NOT to tie VLAN members to one physical segment. I assume that's why this is the default way VLAN broadcasts work in FortiOS. You elaborate that this might have disadvantages in large networks which is a corner case in my opinion - connectivity before efficiency. At least, the student should not get the impression that without defining forwarding domains VLANs are not correctly set up.

    diag command: only 16 seconds are not sufficient to explain the data which you can obtain from the output, which is a pity. As we all know, diag command are essential, and essentially not undocumented.