Dell PowerConnect 7048P User Manual - Page 689

What are Protected Ports? The switch supports up to three separate groups of protected ports. Traffic can flow between protected ports belonging to different groups, but not within the same group. A port can belong to only one protected port group. You must remove an interface from one group before adding it to another group. Port protection occurs within a single switch. Protected port configuration does not affect traffic between ports on two different switches. No traffic forwarding is possible between two protected ports. What is Link Local Protocol Filtering? The Link Local Protocol Filtering (LLPF) feature can help troubleshoot network problems that occur when a network includes proprietary protocols running on standards-based switches. LLPF allows a PowerConnect 7000 Series switch to filter out various Cisco® proprietary protocol data units (PDUs) and/or ISDP if problems occur with these protocols running on standards-based switches. If certain protocol PDUs cause unexpected results, LLPF can be enabled to prevent those protocol PDUs from being processed by the switch. The LLPF feature can be configured per-port to block any combination (or all) of the following PDUs: • Industry Standard Discovery Protocol (ISDP) • VLAN Trunking Protocol (VTP) • Dynamic Trunking Protocol (DTP) • UniDirectional Link Detection (UDLD) • Port Aggregation Protocol (PAgP) • Shared Spanning Tree Protocol (SSTP) Access Control Lists (ACLs) and LLPF can exist on the same interface. However, the ACL rules override the LLPF rules when there is a conflict. Similarly, DiffServ and LLPF can both be enabled on an interface, but DiffServ rules override LLPF rules when there is a conflict. Configuring Port-Based Traffic Control 689