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Forum Replies

  1. Hi Hans,

    Best to do it on both sides. Your switch(es) will complain when you receive traffic for VLANs that are not allowed on the trunk. It’s best practice to ensure that both ends of the trunk have the same configuration.


  2. Hello Rene.
    Could you explain me what’s the difference between show ip interface brief and show interface fa0/x switchport? I’m asking this because you use first the show ip interface to check the status of a swichport (up/down) and the other to check operational mode. My question is why you don’t use only interface fa0/x switchport to get both information ( status and operatinal mode?

  3. Hello Rodrigo

    There are various ways to show the status of interfaces and each command provides different information and in different formats. The command initially chosen by Rene is the show ip interface brief will show the status and protocol of all the interfaces in a list, so you get a general picture of all interfaces with one command. If any of those interfaces are configured with IP addresses, those are also displayed.

    The show interface fa0/x switchport command will show the switchport configuration of a single port in detail. This can be used when

    ... Continue reading in our forum

  4. Are you familiar with the switch error - %sw_matm-4-macflap_notif. What causes them? What is flapping?

  5. Hi Jason,

    This message shows up when your switch receives a frame with the same source MAC address on two different interfaces.

    Do you see this for one MAC address or multiple? If you see multiple MAC address, you might have a L2 loop. If you only see one source MAC address, it’s probably a misconfiguration. Track it down like this:

    SW1#show mac address-table dynamic address 0017.94a5.a618 
              Mac Address Table
    Vlan    Mac Address       Type        Ports
    ----    -----------       --------    -----
     200    0017
    ... Continue reading in our forum

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