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
254 Appendix A: Troubleshooting BMD00113, September 2009
sFlow Network Sampling
In addition to statistical counters, the GbE2c can be configured to collect periodic samples of the
traffic data received on each port. For each sample, 128 bytes are copied, UDP-encapsulated, and
sent to the configured sFlow analyzer.
For each port, the sFlow sampling rate can be configured to occur once each 256 to 65536 packets.
A sampling rate of 256 means that one sample will be taken for approximately every 256 packets
received on the port. The sampling rate is statistical, however. It is possible to have slightly more or
fewer samples sent to the analyzer for any specific group of packets (especially under low traffic
conditions). The actual sample rate becomes most accurate over time, and under higher traffic flow.
sFlow sampling has the following restrictions:
Sample Rate—The fastest sFlow sample rate is 1 out of every 256 packets.
ACLs—sFlow sampling is performed before ACLs are processed. For ports configured both
with sFlow sampling and one or more ACLs, sampling will occur regardless of the action of the
ACL.
Port Mirroring—sFlow sampling will not occur on mirrored traffic. If sFlow sampling is
enabled on a port that is configured as a port monitor, the mirrored traffic will not be sampled.
Note – Although sFlow sampling is not generally a CPU-intensive operation, configuring fast
sampling rates (such as once every 256 packets) on ports under heavy traffic loads can cause switch
CPU utilization to reach maximum. Use larger rate values for ports that experience heavy traffic.