About sFlow settings

Sampled flow (sFlow) is a technology for monitoring traffic in data networks containing switches and routers. The sFlow monitoring feature helps to configure an Ethernet network to send sFlow traffic to a list of specified collectors. sFlow can be configured only on Ethernet Interconnect Modules (ICM) in both Virtual Connect Manager and HPE Synergy model.

The sFlow system consists of a sFlow agent embedded in an Ethernet interconnect module and a remote sFlow collector. The sFlow agent collects interface counter information and packet information and encapsulates the sampled information in sFlow packets. When the sFlow packet buffer is full, or the aging timer (fixed to 1 second) expires, the sFlow agent encapsulates the sFlow packets in the UDP datagrams. The UDP datagrams are then sent to the specified sFlow collector. The sFlow collector analyzes the information and displays the results. One sFlow collector can monitor multiple sFlow agents.

sFlow provides the following sampling mechanisms:
  • Flow sampling — Obtains packet information.

  • Counter polling — Obtains interface counter information.

Flow sampling directions:
  • Ingress — Ensures that the incoming packets are actually from the networks from which they claim to originate.

  • Egress — Monitors and restricts the outgoing packets of information from one network to another.

The sFlow setup primarily involves:
  1. Configuring an Ethernet network that is part of an uplink set.

  2. Configuring an sFlow agent's IP address.

  3. Adding collectors, assigning packet, and header sizes.

  4. Adding ports, enabling sampling, and polling function on interconnect module ports.

The sampled data is delivered through a configured network to a collector. The collector identity and network data are associated with the sFlow agent. The sFlow configuration is supported on the following devices:
  • HPE Virtual Connect SE 40Gb F8 Module for HPE Synergy

sFlow limitations

  • The IPv4 address of sFlow agent and interconnect management interface cannot be in the same subnet.

  • The maximum number of ports that can be sampled or polled per logical interconnect is 196.

  • The sFlow monitoring suspends on a VC when the CPU usage crosses a predetermined threshold. The sFlow monitoring resumes once the CPU usage falls below the lower threshold.

  • A maximum of three sFlow collectors are supported per logical interconnect.