Default forwarding mode?

hedhrtshedhrts Posts: 74Member ■■□□□□□□□□
For a 2950. I'm trying to find documentation on the cisco web site, or the command on the switch to find out what it defaults to.

1. store and forward
2. fragment-free
3. cut through

Does anyone have a link or an answer?

Comments

  • steve-o87steve-o87 Posts: 274Member
    Hi,

    2950's only support store and forward, I think. icon_scratch.gif

    If I am wrong someone please correct me :)

    Good Luck
    I am the lizard King. I can do anything.
  • HumperHumper Posts: 647Member
    I believe all switches now use store and forward because of the speed. Dont quote me on that, someone else will be able to provide you more information.
    Now working full time!
  • loboernestoloboernesto Posts: 94Member ■■□□□□□□□□
    I remember reading something about it somewhere there, it said is store and forward...
    I also think that they do only store and forward.

    http://www.cisco.com/en/US/products/hw/switches/ps628/products_configuration_guide_book09186a00801a6b78.html

    cheers
  • hedhrtshedhrts Posts: 74Member ■■□□□□□□□□
    I remember reading something about it somewhere there, it said is store and forward...
    I also think that they do only store and forward.

    http://www.cisco.com/en/US/products/hw/switches/ps628/products_configuration_guide_book09186a00801a6b78.html

    cheers

    Thanks for the link. So far it looks like you're right.
    Building the Address Table
    With multiple MAC addresses supported on all ports, you can connect any port on the switch to
    individual workstations, repeaters, switches, routers, or other network devices. The switch provides
    dynamic addressing by learning the source address of packets it receives on each port and adding the
    address and its associated port number to the address table. As stations are added or removed from the
    network, the switch updates the address table, adding new dynamic addresses and aging out those that
    are not in use.
    The aging interval is configured on a per-switch basis. However, the switch maintains an address table
    for each VLAN, and STP can accelerate the aging interval on a per-VLAN basis.
    The switch sends packets between any combination of ports, based on the destination address of the
    received packet. Using the MAC address table, the switch forwards the packet only to the port or ports
    associated with the destination address. If the destination address is on the port that sent the packet, the
    packet is filtered and not forwarded. The switch always uses the store-and-forward method: complete
    packets are stored and checked for errors before transmission
    .
  • Danman32Danman32 Posts: 1,243Member
    Cut-through and fragment free have the least latency, but have least control over the frames as well. With store and forward, the appliance (switch) can fully analyze and manage the frame before forwarding it out.
    Since Cisco is all about full management and security, only store and forward would make sense.
  • bmaurobmauro Posts: 307Member
    I was just leafing through Lammle's CCNA book - and came across Fragment-Free switching and he mentions that 1900 series switches use this method as the default.

    News to me.
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