ExtremeSwitching (EXOS)

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vlan interface question

  • 1.  vlan interface question

    Posted 10-24-2018 11:01

    Can I assign the same vlan interface to different extreme? Based on the definition of what a VLAN is, I think I can, but my boss thinks not. We had a big argument with him, please tell me friends. I assigned and everything worked fine for me, because of him I removed them, and I cannot search for devices on the ARP table. You have to look for the FDB table, which is extremely time consuming


  • 2.  RE: vlan interface question

    Posted 10-24-2018 11:08
    Alexey - are you saying you put the same IP address onto a VLAN interface that's the same on multiple switches? There's no issue simply having a vlan interface on each switch, but the IP's should still be unique.


  • 3.  RE: vlan interface question

    Posted 10-24-2018 11:08
    you want to tell that on switch 1 and on switch 2 I can use on the same VLAN , the same ip address on VLAN interface? I did and everything worked for me.


  • 4.  RE: vlan interface question

    Posted 10-24-2018 11:08
    please help me Eric


  • 5.  RE: vlan interface question

    Posted 10-24-2018 11:08
    Please post a quick diagram of your layout as I think we might be misunderstanding each other.


  • 6.  RE: vlan interface question

    Posted 10-24-2018 11:08
    look
    (Switch 1 and switch 2 are connected to each other on port 24 each. End devices (printers) on port 11 on the first switch and port 12 on the second switch.)
    switch 1
    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.1/23
    configure vlan printers add ports 11 untagged
    configure vlan printers add ports 24 tagged
    switch 2
    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.1/23
    configure vlan printers add ports 12 untagged
    configure vlan printers add ports 24 tagged.

    I wrote everything correctly?



  • 7.  RE: vlan interface question

    Posted 10-24-2018 11:08
    In this case, no - you should not be using the same IP address on each switch. Connecting to that IP will yield unreliable results as both IP's will respond to the same ARP requests and during initialization (when a gratuitous arp is sent, one will likely back off seeing that another device shares that IP). It probably works for what you described (seeing IP's associated with other devices), as that information is pulled from broadcast traffic, but those IP's should be independent to allow for management, proper ARP cache for end stations, etc.


  • 8.  RE: vlan interface question

    Posted 10-24-2018 11:08
    ok, thank you so much.
    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.1/23
    configure vlan printers add ports 12 untagged

    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.1/23
    configure vlan printers add ports 11

    or

    switch 1
    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.1/23
    configure vlan printers add ports 11 untagged
    configure vlan printers add ports 24 tagged
    switch 2
    create vlan printers tag 10
    configure vlan printers ipaddress 10.1.10.2/23
    configure vlan printers add ports 12 untagged
    configure vlan printers add ports 24 tagged


  • 9.  RE: vlan interface question

    Posted 10-24-2018 11:08
    That would be a more appropriate configuration. You'll be able to individually manage each switch over the network, the end-stations will have the proper ARP entries for both and you'll still have the visibility into the iparp tables that you're looking for.


  • 10.  RE: vlan interface question

    Posted 10-24-2018 11:08
    thank you very much) can see this question if you can and give some ideas?
    https://community.extremenetworks.com/extreme/topics/missing-packages-in-one-vlan


  • 11.  RE: vlan interface question

    Posted 10-24-2018 11:29
    Can you reuse a VLAN name and ID? Yes, as long as they are not trunked together in some way. If you use VLAN DATA TAG 10 in location A. In location B you use VLAN DATA TAG 10 and the only connection between the 2 locations is a Layer 3 connection then YES. I use this all the time as it makes remembering the VLAN names and ID's easy as they are the same. Just be sure you never turn that Layer 3 into a Layer 2 connection unless you have fully checked all the VLANs you are planning to pass across it.

    Can you reuse the IP Address? The answer there is maybe, but not a best practice. If the VLAN is only meant to talk in one location and never go to any other location then in theory yes you could use it and route internally to that VLAN. In my experience someone will change that at some point and then you have a re-IP scenario to work through. I would just give it a different IP range to begin with and just not route it.