Help with Cisco Switch Configuration

Discussion in 'Networking & Security' started by board2death986, Sep 10, 2014.

  1. board2death986

    board2death986 [H]ard|Gawd

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    I have someone I'm trying to help out with a simple network that inherited some cisco switches. Apparently they were defaulted but VLAN 1 is still disabled (I understand why, not arguing that), but they need it re-enabled. I'm not too familiar with Cisco IOS as I haven't touched Cisco since taking some classes for the CCNA over 5 years ago. . .can anyone help a guy out with some tips on the commands I will need? I believe the models of switches are the 2950 for the rooms and a couple of 3750 switches for the main closet.

    I already ordered the usb->console->RJ45 cable I'm going to need to connect, then I suppose I'll have to install drivers and use putty to access the console. . .that's where I'm currently at.
     
  2. boss99

    boss99 2[H]4U

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    I didn't think that VLAN 1 could be removed or disabled, per se.

    I knew that you can isolate it by not assigning any trunk or access ports, but not outright disable it
     
  3. board2death986

    board2death986 [H]ard|Gawd

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    You are probably right about that, as I said I'm not too familiar with switch configurations. I'm trying to help this guy out so if you have any tips or links that would help that would be awesome.
     
  4. Dark Shade

    Dark Shade [H]ard|Gawd

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    I do believe you need to remove the vlan.dat configuration file on the flash memory.
     
  5. boss99

    boss99 2[H]4U

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    Can you post the existing config?
     
  6. board2death986

    board2death986 [H]ard|Gawd

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    That looks like a good lead, I've found some documentation from Cisco on that process. Thanks Dark Shade.
     
  7. board2death986

    board2death986 [H]ard|Gawd

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    No, I do not have access to the switches again until I am onsite. The issue concerning VLAN1 was confirmed from another technician who simply showed up to verify that the hardware wasn't the problem since the equipment is covered under their warranty, but as the issue was confirmed to be from the configuration they simply picked up their bags and left. I believe one of the switches was configured already so I can confirm the VLAN situation there before changing the others.
     
  8. Cmustang87

    Cmustang87 [H]ardness Supreme

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    You have to be careful when incorporating inherited Cisco switches and placing them into a production environment.

    VTP information and VLAN information persists through mem erases. You will need to delete the VLAN Database and also set the VTP to revision 0.

    You can see here further about removing the VLAN.dat file on the switch:
    http://www.mcmcse.com/cisco/guides/vlandat.shtml

    Here you can see how to reset VTP revision to 0 by means of setting VTP mode to "transparent":
    http://www.freeccnaworkbook.com/workbooks/ccna/configuring-vtp-transparent-mode-and-vtp-pruning
     
  9. board2death986

    board2death986 [H]ard|Gawd

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    Well luckily it's reversed and the users were placed into the Cisco environment. They inherited a space that had the switches already installed.
     
  10. MysticRyuujin

    MysticRyuujin Limp Gawd

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    You should probably just figure out what the current config is before doing anything...but....

    Factory Default:
    wr erase
    delete flash:vlan.dat
    reload

    If you see any files like:
    private-config.text
    config.text

    I'd delete those too

    :)
     
  11. JeffBlair

    JeffBlair Limp Gawd

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    The VLAN1 is the default for that switch. It's to give the switch an IP so you can configure it without the console cable. I would try giving it an IP address first, and see if that does what you're looking for.

    conf t
    int vlan1
    ip add 192.168.x.x 255.255.255.0 <------ IP/Subnet on your network
    no shut
    exit
    ip route 192.168.x.x <----- your gateway
    exit
    wr mem


    You don't need to give each interface an IP/VLAN if you don't want to.
     
  12. MysticRyuujin

    MysticRyuujin Limp Gawd

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    ip route doesn't work or do anything unless ip routing is enabled and 2950s don't have that capability.

    ip default-gateway is the correct command.
     
  13. JeffBlair

    JeffBlair Limp Gawd

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    Doh, that's right. I'm a lot more familer with the routers than switches.
     
  14. FrankD400

    FrankD400 Limp Gawd

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    Are you strictly talking about the management interface on VLAN1? Your question is unclear.. I'm not sure what you mean by 'VLAN1 was disabled' and you 'understand why'.

    Are there other VLANs configured? What are the trunks like? The only way we can truly help is if you post configs and explain what it does and then what you'd like it to do instead.
     
  15. tangoseal

    tangoseal [H]ardness Supreme

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    No config.. we cant really help you through assumption. Get that config and lets see where we stand. :)