User guide
September 2009
OmniSwitch 6400/6850/6855/9000/9000E------ Release 6.4.2.R01 Page 39 of 79
• Multiple routing instances within the same physical switch. Each VRF instance is associated
with a set of IP interfaces and creates and maintains independent routing tables. Traffic
between IP interfaces is only routed and forwarded within those interfaces/routes that belong
to the same VRF instance.
• Multiple instances of IP routing protocols, such as static, RIP, IPv4, BGPv4, and OSPFv2 on
the same physical switch. An instance of each type of protocol operates within its own VRF
instance.
• The ability to use duplicate IP addresses across VRF instances. Each VRF instance maintains
its own IP address space to avoid any conflict with the service provider network or other
customer networks.
• Separate IP routing domains for customer networks. VRF instances configured on the
Provider Edge (PE) are used to isolate and carry customer traffic through the shared provider
network.
The Multiple VRF feature uses a context-based command line interface (CLI). When the switch
boots up, a default VRF instance is automatically created and active. Any commands subsequently
entered apply to this default instance. If a different VRF instance is selected, then all subsequent
commands apply to that instance. The CLI command prompt indicates which instance is the active
VRF CLI context by adding the name of the VRF instance as a prefix to the command prompt (for
example, vrf1: ->).
Note:
Refer to the “Configuring Multiple VRF” chapter in the OmniSwitch AOS Release 6
Configuration Guide for a list of VRF supported features and commands.
Note: A switch running multiple VRF instances can only be managed with SNMPv3. A context
must be specified that matches the VRF instance to be managed.
Pause Control/Flow Control
PAUSE frames are used to pause the flow of traffic between two connected devices when traffic
congestion occurs. PAUSE frame flow control provides the ability to configure whether or not the
switch will transmit and/or honor PAUSE frames on an active interface. This feature is only supported
on interfaces configured to run in full-duplex mode.
In addition to configured PAUSE frame flow control settings, this feature also works in conjunction
with auto-negotiation to determine operational transmit/receive settings for PAUSE frames between
two switches. Note that the configured PAUSE frame flow control settings are overridden by the
values that are determined through auto-negotiation.
End-to-end flow control is supported on OmniSwitch 6400, 6850, and 6855 switches running in
standalone mode. When working in stack mode, these switches will honor received pause messages on
any port of any stack. In the case of an OmniSwitch chassis, received pause frames will be honored and
processed.
To enable end to end flow control on 48-port standalone OmniSwitch 6400 and 6850 switches, a
dedicated VLAN must be configured and RX/TX pause enabled. In the case of 24-port standalone
switches, enabling RX/TX pause is sufficient.