Not sure why you think it only uses the destination, so I may be answering the wrong question. The three flow mask modes are dependant on the type of access list and do not all rely solely on the destination address:
a.. destination-ip-The least-specific flow mask. The PFC maintains one MLS entry for each destination IP address. All flows to a given destination IP address use this MLS entry. a.. source-destination-ip-The PFC maintains one MLS entry for each source and destination IP address pair. All flows between a given source and destination use this MLS entry regardless of the IP protocol interfaces. a.. ip-flow-The most-specific flow mask. The PFC creates and maintains a separate MLS cache entry for each IP flow. An ip-flow entry includes the source IP address, destination IP address, protocol, and protocol interfaces. URL for more info: http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/ios127xe/config/ mls.htm#xtocid60053 Regards, Gaz ""Sergio"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hi all. > > Im studying for the CCNP-Switching exam. I have a question about MLS's Flow > Masks. In my CiscoPress book, the author says: > > "The MLS-SE uses flow masks modes to determine how packets are compared to > MLE entries in the MLS cache.The flow mask mode is based on the access list > configured on the MLS router interfaces. The MLS-SE learns of the flow mask > trough MLSP messages from each MLS-RP for wich the MLS-SE is performing > Layer 3 switching. " > > I dont understand why the flow mask mode is based on the access list > configured, since all the 3 flow mask modes just look at the DESTINATION IP > address. So, if the MLS-RP has an access list that deny some traffic, that > traffic just will be forwarded and never will arrive at the switch's > backpanel. If the MLS-RP has an access list that permit the traffic, the > MLS-SE will cache it and it will only chek the Destination address for Layer > 3 switching. > > So, why are flow mask modes based on the configured access list? > > Thanks for your help. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29519&t=29518 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
