RFC 2643 Cabletron's SecureFast VLAN Operational Model August 1999 4.1.2 Inverse Resolve Server......................... 15 4.1.3 Local Delete Server............................ 18 4.2 Topology Service Center.............................. 18 4.2.1 Neighbor Discovery Server...................... 18 4.2.2 Spanning Tree Server........................... 18 4.2.2.1 Creating and Maintaining the Spanning Tree........... 19 4.2.2.2 Remote Blocking........................ 19 4.2.3 Link State Server.............................. 20 4.3 Resolve Service Center............................... 21 4.3.1 Table Server................................... 22 4.3.2 Local Server................................... 22 4.3.3 Subnet Server.................................. 22 4.3.4 Interswitch Resolve Server..................... 22 4.3.5 Unresolvable Server............................ 23 4.3.6 Block Server................................... 23 4.4 Policy Service Center................................ 24 4.4.1 Unicast Rules Server........................... 24 4.5 Connect Service Center............................... 25 4.5.1 Local Server................................... 25 4.5.2 Link State Server.............................. 25 4.5.3 Directory Server............................... 26 4.6 Filter Service Center................................ 26 4.7 Path Service Center.................................. 26 4.7.1 Link State Server.............................. 26 4.7.2 Spanning Tree Server........................... 27 4.8 Flood Service Center................................. 27 4.8.1 Tag-Based Flood Server......................... 27 5. Monitoring Call Connections.............................. 27 5.1 Definitions.......................................... 27 5.2 Tapping a Connection................................. 28 5.2.1 Types of Tap Connections....................... 28 5.2.2 Locating the Probe and Establishing the Tap Connection.......... 29 5.2.3 Status Field................................... 30 5.3 Untapping a Connection............................... 31 6. Interswitch Message Protocol (ISMP)...................... 32 6.1 General Packet Structure............................. 32 6.1.1 Frame Header................................... 32 6.1.2 ISMP Packet Header............................. 33 6.1.2.1 Version 2.............................. 33 6.1.2.2 Version 3.............................. 34 6.1.3 ISMP Message Body.............................. 35 6.2 Interswitch BPDU Message............................. 35 6.3 Interswitch Remote Blocking Message.................. 36 6.4 Interswitch Resolve Message.......................... 37 6.4.1 Prior to Version 1.8........................... 37 6.4.2 Version 1.8.................................... 41 Ruffen, et al. Informational