Extreme Networks ExtremeWare 7.7, Command Reference Manual

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1802 ExtremeWare 7.7 Command Reference Guide
IGP Commands
configure ospf add vlan area
configure ospf add vlan [<vlan name> | all] area <area identifier>
{passive}
Description
Enables OSPF on one or all VLANs (router interfaces).
Syntax Description
Default
Area 0.0.0.0
Usage Guidelines
Associates a VLAN (router interface) with an OSPF area. By default, all router interfaces are associated
with area 0.0.0.0. Any OSPF network that contains more than one area is required to have an area
configured as area 0, also called the
backbone . All areas in an autonomous system must be connected to
the backbone. When designing networks, you should start with area 0, and then expand into other
areas.
The backbone allows summary information to be exchanged between ABRs. Every ABR hears the area
summaries from all other ABRs. The ABR then forms a picture of the distance to all networks outside of
its area by examining the collected advertisements, and adding in the backbone distance to each
advertising router.
When a VLAN is configured to run OSPF, by default you must assign it to an area.
On the “e” series switches.
The Summit “e” series of switches allow up to two non-passive
interfaces.If a user attempts to configure more than two non-passive interfaces, the Summit switch
displays the following warning message:
Cannot enable OSPF on vlan <name>. Non-passive interface limit reached.
Using OSPF and MPLS.
The following detailed information pertains to using OSPF in conjunction
with MPLS. When the peer LSR is also an Extreme switch, the following options are available for
ensuring that an OSPF route is advertised for the tunnel endpoint IP address:
• A route is advertised when OSPF is enabled on the VLAN to which the IP address is assigned (using
the
configure ospf add vlan
command on the peer switch).
• A route is advertised when the peer switch is configured to distribute direct routes into the OSPF
domain (via the
enable ospf export direct
command). The export option should be used when
the tunnel LSP needs to cross OSPF area boundaries or when the Extreme Standby Routing Protocol
(ESRP) is enabled on the VLAN to which the IP address is assigned.
vlan name Specifies a VLAN name to be associated with an OSPF area.
all Specifies all VLANs to be associated with an OSPF area.
area identifier Specifies the area to which the VLAN is assigned.
passive Specifies to stop sending and receiving hello packets on this interface.