Method and apparatus for reducing flooding in bridged networks
AssigneeCisco Technology, Inc.
InventorSenthil Sivakumar
Life of this patent
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Abstract
A method and apparatus for reducing flooding in a bridged network. The invention generally allows broadcast flooding for a predefined limited time period to permit mapping of a MAC address to a port by the bridge and disallows broadcast flooding for a second predefined time period. After the second time period expires, the process is repeated to allow the bridge to flood the networks for the predefined limited time period again. The bridge allows or disallows broadcasts flooding independently based on the destination MAC address.
Claims12
A method for controlling flooding in a bridged network having a bridge connected to a plurality of networks, the method comprising:
- passing a packet to a filtering module, and indicating a MAC address associated with the packet to the filtering module;
- determining whether the received MAC address exists in a table or needs to be added as an entry to the table;
- if the MAC address already exists in the table then incrementing a packet count field, the packet count field associated with the MAC address already existing in the table and indicating how many packets have been sent to the MAC address;
- if a quiet flag associated with the MAC address is not set to true within the table and a flooding timer associated with the MAC address has not expired, the flooding timer initially set to a first predetermined value and decremented periodically, then broadcasting the received packet to a plurality of interfaces;
- and
- if the quiet flag associated with the MAC address is set within the table and a restart timer associated with the table has expired, the restart timer initially set to a second predetermined value and decremented periodically, then;
- resetting the quiet flag in the table to false;
- and
- setting a flooding timer to an initial value;
- and broadcasting the received packet to a plurality of interfaces.
A computer program product containing instructions which, when executed by a computer, controls flooding in a bridged network having a bridge connected to a plurality of networks, by:
- passing a packet to a filtering module, and indicating a MAC address associated with the packet to the filtering module;
- determining whether the received MAC address exists in a table or needs to be added as an entry to the table;
- if the MAC address already exists in the table then incrementing a packet count field, the packet count field associated with the MAC address already existing in the table and indicating how many packets have been sent to the MAC address;
- if a quiet flag associated with the MAC address is not set to true within the table and a flooding timer associated with the MAC address has not expired, the flooding timer initially set to a first predetermined value and decremented periodically, then broadcasting the received packet to a plurality of interfaces;
- and
- if the quiet flag associated with the MAC address is set within the table and a restart timer associated with the table has expired, the restart timer initially set to a second predetermined value and decremented periodically, then:
- resetting the quiet flag in the table to false;
- and
- setting a flooding timer to an initial value;
- and broadcasting the received packet to a plurality of interfaces.
Dependencies are inferred from the claim text.