How to route between VLANs using a Layer 3 switch. - Network

This is a discussion on How to route between VLANs using a Layer 3 switch. - Network ; I am trying to figure out how to get an echo response when I ping a device on a different VLAN. Just to test things and get them to work, currently, I have two Dell Powerconnect 6024 switches on my ...

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Thread: How to route between VLANs using a Layer 3 switch.

  1. How to route between VLANs using a Layer 3 switch.

    I am trying to figure out how to get an echo response when I ping a
    device on a different VLAN.

    Just to test things and get them to work, currently, I have two Dell
    Powerconnect 6024 switches on my desk. I will call them S1 and S2. S1
    is connected to our internal LAN. S2 is connected to S1 via a trunk
    port on each switch and nothing else. I have some ports set up to be
    on VLAN 10 and some to be on VLAN 20. I have IP Addresses assigned to
    both VLANs on each switch as follows:

    S1:
    VLAN 10, 192.168.0.40
    VLAN 20, 192.168.1.1

    S2:
    VLAN 10, 192.168.0.32
    VLAN 20, 192.168.1.2

    On S1, Port 24 is set up as a Trunk port with VLAN 10 & 20 both added
    to it. It is connected by a cable to Port 1 on S2, also configured as
    a trunk port with both VLAN 10 & VLAN 20 added to it.

    Initially, I was trying to set up static routes using an white paper on
    Dell's web site,
    http://www.dell.com/downloads/global...pp_note_38.pdf.

    However, I received a reply from a Dell tech/engineer indicating that
    this paper is misleading and that the Layer 3 switch (Powerconnect
    6024) would automatically route between directly connected networks.

    I am trying to test this by simply pinging the ip addresses of VLAN 20
    from a computer connected to a port that is on VLAN 10. All I can get
    is "Request timed out".

    For example, my computer is connected to port 15 on S1 & has the IP
    address, 192.168.0.103. I can ping 192.168.0.40, the IP address of
    VLAN 10 on S1 with replies and I can ping 192.168.0.32, the IP address
    of VLAN 10 on S2 and get replies. I cannot, however, get replies when
    I ping 192.168.1.1 or 192.168.1.2, which is VLAN 20 on S1 & S2,
    respectively.

    This summarizes my issue. I will follow this with replies to this
    message that contain more information.

    If anyone is familar with configuring VLANs using Layer 3 & Layer 2
    switches, please help.

    Thanks,

    Mike


  2. Re: How to route between VLANs using a Layer 3 switch.

    Below is my original post on Dells forum for managed switches. It
    describes a different configuration than the one I descirbed in my
    original post here. I have since simplified it to that configuration
    since I posted this.

    **********Beginning of post**********
    I am having trouble understanding how set up static routes to access
    one VLAN from another. We have a Dell Powerconnect 6024, Layer 3
    managed switch and two Dell Powerconnect 3348, Layer2 Managed switches.

    I am working from an article on Dell's web site called "What is VLAN
    Routing?" It is "PowerConnect Application Note #38". It is available
    at the link,
    http://www.dell.com/downloads/global...pp_note_38.pdf.
    I believe I understand everything in the article, except for two lines
    on page 4, step 4, in which the static routes are set up. They are as
    follows:

    Dell-6024(config)# ip route 10.10.0.0 255.255.255.0 10.10.0.2
    Dell-6024(config)# ip route 10.20.0.0 255.255.255.0 10.20.0.2

    These are the routes defined on the 6024, Layer 3 switch. There are
    two basic things I don't understand in these statements. First, the
    destination network and the gateway to get to the destination network
    are on the same subnet in each case. My limited understanding of
    static routes tells me that, in order to grant access to another
    subnet, an IP address for one interface of a router must be in the same
    subnet as the computers that need access to the other subnet. In other
    words, in order for a computer with an IP address of, say, 10.10.0.5 on
    the 10.10.0.0/24 subnet to access the computer 10.20.0.5 on the
    10.20.0.0/24 subnet, I thought the following route would be required,

    ip route 10.20.0.0 255.255.255.0 10.10.0.2

    where 10.20.0.0 255.255.255.0 is the destination subnet and 10.10.0.2
    is the router interface on the same subnet as the 10.10.0.5 computer.

    In this article, the 10.10.0.2 gateway or "next hop" is on the same
    subnet as the destination subnet, 10.10.0.0 255.255.255.0. I don't
    understand this. Could the fact that ports 23 & 24 on the 6024 are
    defined as Trunk ports have anything to do with this? Could these
    lines be a couple of typeos in which the destination subnets are each
    on the wrong line in this document?

    The second thing I don't understand is what entities in this article
    are assigned the 10.10.0.2 and 10.20.0.2 IP addresses. Are these IP
    addresses assigned to the appropriate 3348 switches? VLAN 10 & VLAN 20
    are assigned 10.10.0.1 & 10.20.0.1, respectively, on the 6024 switch.
    So, they can't be the VLAN IP addresses on the 6024 switch.

    I have tried varoius scenarios for creating static routes. I tried
    setting the gateway addresses to be the VLAN addresses on the 6024
    switch, but I got an error saying I can't use an IP address assigned to
    the device. I tried setting them to the VLAN IP addresses assigned on
    the 3348 switches and this didn't work either. In all cases, I tried
    defining static routes with the gateway address on the opposite
    subnet, as well as on the destination subnet. I tried placing a
    computer on each subnet and pinging the other computer, as well as
    pinging the IP addresses assigned to the VLANs on the switches, all
    without success. Do I need to enable ECHO on the switches?
    Thank you for any information you can provide.


  3. Re: How to route between VLANs using a Layer 3 switch.

    A Dell tech responded to my previous reply as follows:

    ************Tech's reply*************
    The whitepaper is a bit misleading. The 6024 will automatically route
    between directly connected networks. If the only devices you are using
    are the 6024 and two 3348s, you would not need to configure static
    routes.

    To route between the VLANs, you would simply need to bind the ip
    addresses of the different networks to their respective VLAN, configure
    the uplinks between the switches to trunk the necessary VLANs, and
    configure the client ports on each switch as access mode ports in their
    VLAN. When a port goes active that is a member of a VLAN, the VLAN
    interface will also be brought up. Once the VLAN interface is up, that
    network will be seen as directly connected and will be seen in the
    routing table (show ip route).

    *********End of Tech's reply**********

    After a few more messages back and forth, I posted the following:

    **************My last post on Dell's Forum**********
    I have simplified the configuration. Now, I have two 6024 switches. I
    am trying to use the Layer 3 capabilities of one, which I will call S1,
    and only the Layer 2 capabilities of the other one, which I will call
    S2.

    My workstation is connected to Port g15 on S1. It is also connected to
    S2 via a Serial cable.

    I have set up Port g24 of S1 to be a trunk port with VLAN 10 & VLAN 20
    binded to it. It is connected by a cable to Port g1 of S1, which is
    also a trunk port with VLAN 10 & VLAN 20 binded to it.


    ********Configuration of S1*********

    Using Telnet to connect to S1, the following shows that Port g24 is in
    Trunk mode and has VLAN 10 & 20 added to it.

    console# show interface switchport ethernet g24
    Port : g24
    Port Mode: Trunk
    Gvrp Status: disabled
    Ingress Filtering: true
    Acceptable Frame Type: admitAll
    Ingress UnTagged VLAN ( NATIVE ): 1
    Port is member in:

    Vlan Name Egress rule Port Membership Type
    ---- -------------------------------- ----------- --------------------
    1 1 Untagged System
    10 10 Tagged Static
    20 20 Tagged Static

    The following shows that 192.169.0.40 is binded to VLAN 10 and
    192.168.1.1 is binded to VLAN 20 on S1.

    console# show ip interface vlan 10
    Proxy ARP is disabled

    IP Address Type Directed
    Broadcast
    ----------------------- --------- -----------
    192.168.0.40/24 static disable

    console# show ip interface vlan 20
    Proxy ARP is disabled

    IP Address Type Directed
    Broadcast
    ----------------------- --------- -----------
    192.168.1.1/24 static disable

    The following shows that 192.168.0.0/24 & 192.168.1.0/24 are directly
    connected subnets on S1.

    console# show ip route
    Maximum Parallel Paths: 4 (4 after reset)
    Codes: C - connected, S - static, R - RIP, O - OSPF, E - OSPF external
    C 192.168.0.0/24 is directly connected
    vlan 10
    C 192.168.1.0/24 is directly connected
    vlan 20
    C 192.168.10.0/24 is directly connected
    vlan 1

    The following shows that Port g15, to which my workstation is
    connected, is a member of VLAN 10.

    console# show interface switchport ethernet g15
    Port : g15
    Port Mode: Access
    Gvrp Status: disabled
    Ingress Filtering: true
    Acceptable Frame Type: admitAll
    Ingress UnTagged VLAN ( NATIVE ): 10
    Port is member in:

    Vlan Name Egress rule Port Membership Type
    ---- -------------------------------- ----------- --------------------
    10 10 Untagged Static


    ********Configuration of S2*********

    Using HyperTerminal on a Serial cable connection between my worstation
    and S2, the following shows that Port g1 is in Trunk mode and has VLAN
    10 & 20 added to it.

    console# show interface switchport ethernet g1
    Vlan Name
    Ingress UnTagged VLAN ( NATIVE ): 1
    Port is member in:

    Vlan Name Egress rule Port Membership Type
    ---- -------------------------------- ----------- --------------------
    1 1 Untagged System
    10 10 Tagged Static
    20 20 Tagged Static

    The following shows that 192.169.0.32 is binded to VLAN 10 and
    192.168.1.2 is binded to VLAN 20 on S2.

    console# show ip interface vlan 10
    Proxy ARP is disabled

    IP Address Type Directed
    Broadcast
    ----------------------- --------- -----------
    192.168.0.32/24 static disable

    console# show ip interface vlan 20
    Proxy ARP is disabled

    IP Address Type Directed
    Broadcast
    ----------------------- --------- -----------
    192.168.1.2/24 static disable

    The following shows that 192.168.0.0/24 & 192.168.1.0/24 are directly
    connected subnets on S2.

    console# show ip route
    Maximum Parallel Paths: 4 (4 after reset)
    Codes: C - connected, S - static, R - RIP, O - OSPF, E - OSPF external
    C 192.168.0.0/24 is directly connected
    vlan 10
    C 192.168.1.0/24 is directly connected
    vlan 20
    C 192.168.11.0/24 is directly connected
    vlan 1

    ********End of Configuration Information*********

    In your first reply to my initial request, you wrote, "The 6024 will
    automatically route between directly connected networks. If the only
    devices you are using are the 6024 and two 3348s, you would not need to
    configure static routes."

    Currently, I still cannot get a device on one subnet/VLAN to ping a
    device on the other subnet/VLAN and get a reply. In this
    configuration, I am using the VLAN interfaces, themselves, as the
    "devices" in question. For example, on S1, VLAN 10 is 192.168.040 & on
    S2, it is 192.168.0.32. VLAN 20, on S1, is 192.168.1.1 & on S2 it is
    192.168.1.2. From a DOS prompt on my workstation, which is connected
    to a port on VLAN 10, I cannot get a reply if I ping 192.168.1.1 or
    192.168.1.2. That is, I cannot get a reply from a device on another
    subnet, regardless of which switch it is on.

    I think I am trying to do something simple. But, I am overlooking
    something obvious.

    Any help you can provide would be greatly appreciated.


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