Operation Manual – MSTPH3C S7500 Series Ethernet Switches Chapter 1 MSTP Configuration1-36To do ... Use the command ... RemarksReturn to systemview quit —Enable the digestsnooping functiongloballystpconfig-digest-snoopingRequiredThe digest snooping functionis disabled globally by default.Verify theconfigurationabovedisplaycurrent-configurationYou can execute thiscommand in any view.Note:z The digest snooping function is needed only when your S7500 switch is connectedto other vendors' proprietary spanning tree protocol-adopted switches.z To enable the digest snooping function successfully, you must first enable it on allthe ports of your S7500 switch that are connected to other vendors' proprietaryspanning tree protocol-adopted switches and then enable it globally.z To enable the digest snooping function, the interconnected switches must beconfigured with exactly the same MST region-related configurations (includingregion name, revision level, and VLAN-to-MSTI mapping).z The digest snooping function must be enabled on all the ports of your S7500 switchthat are connected to other vendors' proprietary spanning tree protocol-adoptedswitches in the same MST region.z With the digest snooping function enabled, the VLAN-to-MSTI mapping cannot bemodified.z The digest snooping function is not applicable to edge ports of an MST region.1.7 Rapid Transition Configuration1.7.1 IntroductionDesignated ports on switches adopting RSTP or MSTP use the following two types ofpackets to implement rapid transition:z Proposal packets: Packets sent by designated ports to request rapid transitionz Agreement packets: Packets used to acknowledge rapid transition requestsBoth RSTP and MSTP switches can perform rapid transition operation on a designatedport only when the port receives an agreement packet from the downstream switch.The difference between RSTP and MSTP switches are: