IPv6 Flow

IPv6 Flow Options

• Netflow v9 (aka cflow/jflow)

• Sflow

• IPFix

Common Netflow versions

• Netflow v5 - Fixed record format, no support for IPv6– Supported by Cisco, Juniper, Alcatel

• Netflow v9 - Variable record format/template, supports IPv6– Supported by Cisco and Juniper although

Juniper doesn’t yet support IPv6 traffic reporting in cflowd v9

Cisco IPv6 Netflow v9 Configuration

• General Configuration– ipv6 flow-export version 9– Ipv6 flow-export destination <ip-address>

<port-no>– Ipv6 flow-export template refresh-rate

<rate-value>– Ipv6 flow-export template timeout <timeout-

value>

Cisco IPv6 Netflow

• Interface specific commands– Ipv6 flow ingress– Ipv6 flow egress

CLI Management Commands

• Show ip cache flow

• Clear ip flow stats

IPFix

• IETF working group effort

• Improves on Cisco’s Netflow v9

• See: http://www.nanog.org/meetings/nanog41/presentations/nanog41-ipfix.pdf

Sflow

• Includes packet header information

• Used by Extreme, Force10, Foundry

Things to Watch For

• Simultaneous IPv6 and flow support• Impact of IPv6 flow on router or switch

performance• Corner case behavior:

– MPLS– Multicast– Dropped packets