BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software
Table Of Contents
- Contents
- Figures
- Tables
- Preface
- Part 1: Basic Switching
- Accessing the Switch
- The Management Network
- Local Management Using the Console Port
- The Command Line Interface
- Remote Management Access
- Client IP Address Agents
- Securing Access to the Switch
- Setting Allowable Source IP Address Ranges
- RADIUS Authentication and Authorization
- TACACS+ Authentication
- LDAP Authentication and Authorization
- Secure Shell and Secure Copy
- Configuring SSH/SCP Features on the Switch
- Configuring the SCP Administrator Password
- Using SSH and SCP Client Commands
- SSH and SCP Encryption of Management Messages
- Generating RSA Host and Server Keys for SSH Access
- SSH/SCP Integration with Radius Authentication
- SSH/SCP Integration with TACACS+ Authentication
- End User Access Control
- Ports and Trunking
- Port-Based Network Access Control
- VLANs
- Spanning Tree Protocol
- RSTP and MSTP
- Link Layer Discovery Protocol
- Quality of Service
- Accessing the Switch
- Part 2: IP Routing
- Basic IP Routing
- Routing Information Protocol
- IGMP
- OSPF
- OSPF Overview
- OSPF Implementation in BLADE OS
- OSPF Configuration Examples
- Remote Monitoring
- Part 3: High Availability Fundamentals
- High Availability
- Layer 2 Failover
- Server Link Failure Detection
- VRRP Overview
- Failover Methods
- BLADE OS Extensions to VRRP
- Virtual Router Deployment Considerations
- High Availability Configurations
- High Availability
- Part 4: Appendices
- Index
BLADE OS 5.1 Application Guide
BMD00113, September 2009 Chapter 5: Spanning Tree Protocol 111
Determining the Path for Forwarding BPDUs
When determining which port to use for forwarding and which port to block, the HP GbE2c
Ethernet Blade Switch uses information in the BPDU, including each bridge priority ID. A
technique based on the “lowest root cost” is then computed to determine the most efficient path for
forwarding.
Bridge Priority
The bridge priority parameter controls which bridge on the network is the STP Group root bridge.
To make one switch become the root bridge, configure the bridge priority lower than all other
switches and bridges on your network. The lower the value, the higher the bridge priority. Use the
following command to configure the bridge priority:
/cfg/l2/stg <x>/brg/prio
Port Priority
The port priority helps determine which bridge port becomes the designated port. In a network
topology that has multiple bridge ports connected to a single segment, the port with the lowest port
priority becomes the designated port for the segment. Use the following command to configure the
port priority:
/cfg/l2/stg <STG number>/port <port>/prio <priority value>
Port Path Cost
The port path cost assigns lower values to high-bandwidth ports, such as Gigabit Ethernet, to
encourage their use. The objective is to use the fastest links so that the route with the lowest cost is
chosen. A value of 0 indicates that port cost is computed dynamically based on link speed. This
works when forcing link speed, so it does not just apply to autonegotiated link speed.
By default, all switch ports have the path cost set to 0 (zero). Based on port speed, path cost is
automatically set as follows:
A 10 Gbps link receives a path cost of 2
A 1 Gbps link receives a path cost of 4
A 100 Mbps link receives a path cost of 19
A 10 Mbps link receives a path cost of 100
Configure the port path cost using the following command:
/cfg/l2/stp <STG number>/port <port>/cost <cost value>