Switch VLAN and Trunking

Posted on 2005-04-14
Last Modified: 2012-05-05
I am splitting up my network between business units. The new network will have its own internet connection, distrubution switches and core switches.  Company A has a IP schema of 10.100.x.x and Company B has a newtwork schema of 10.50.x.x. Company A has a nortel passport as the core and the company B has a Cisco 3750 as its core.  What I want to do is trunk the switches so that Comapny A subnet can talk to 10.50.x.x.  I am not sure if the Cisco 3750 is a L3 switch but I have a 2600 that can act as a RPM.

I am a bit cloudy on the config so any help would be apreciated.

Question by:mmahaney
    LVL 79

    Expert Comment

    Yes, the 3750 is a L3 switch.
    Create a new VLAN that just connects between the 3750 and the Passport, or just put an IP address directly on one interface of the 3750 and connect it to an interface on the passport with the same IP subnet.
    You can use RIP to learn routes from each other. Unless you have the Enhanced version of IOS on the 3750, you won't have advanced routing functions like OSPF, but you can always use static routes on both the 3750 and the passport..

    10.100.x.x -- passport <--10.25.25.x---> 3750 --- 10.50.x.x

     3750 basic config (from memory, so syntax should at least be close)
    interface Fast 0/2  <== interface connected to Passport
      ip address
    interface VLAN1
      ip address
    ip route <== IP addressed assigned on Passport
    ip route 10.50.x.x


    Author Comment

    Thanks for the quick post....
    The only issue I am having is that I cannot put an IP address on the interface...

    mi-cat3750.electric.(config)#int gigabitEthernet 1/0/12
    Interface configuration commands:
      arp                     Set arp type (arpa, probe, snap) or timeout
      auto                    Configure Automation
      bandwidth               Set bandwidth informational parameter
      bgp-policy              Apply policy propogated by bgp community string
      carrier-delay           Specify delay for interface transitions
      cdp                     CDP interface subcommands
      channel-group           Etherchannel/port bundling configuration
      channel-protocol        Select the channel protocol (LACP, PAgP)
      dampening               Enable event dampening
      default                 Set a command to its defaults
      delay                   Specify interface throughput delay
      description             Interface specific description
      dot1x                   Interface Config Commands for 802.1x
      duplex                  Configure duplex operation.
      exit                    Exit from interface configuration mode
      fair-queue              Enable Fair Queuing on an Interface
      flow-sampler            Attach flow sampler to the interface
      flowcontrol             Configure flow operation.
      help                    Description of the interactive help system
      hold-queue              Set hold queue depth
      ip                      Interface Internet Protocol config commands
    mi-cat3750.electric.(config-if)#ip ?
    Interface IP configuration subcommands:
      access-group  Specify access control for packets
      arp           Configure ARP features
      dhcp          DHCP
      igmp          IGMP interface commands
      igmp          IGMP interface commands
      verify        verify
    LVL 79

    Accepted Solution

    Try this:
    c3750(config)#int gig 1/0/12
    c3750(config-if)#no switchport
    c3750(config-if)#ip address


    Author Comment

    Cool...thanks that saved my ass.
    I don't know why I was thinking that was more complex than it was.

    Thanks again,
    LVL 79

    Expert Comment

    Glad to help!
    I've been guilty of the same thing - trying to overcomplicate things that have a pretty simple solution...

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