Router Id - Lenovo RackSwitch G8264CS Application Manual

Router ID

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G8264CS Application Guide for ENOS 8.4
Figure 48 on page 469).
The area which contains a virtual link must be a transit area and have full routing
information. Virtual links cannot be configured inside a stub area or NSSA. The
area type must be defined as transit using the following command:
RS 8264CS(config-router-ospf)# area <area index> type transit
The virtual link must be configured on the routing devices at each endpoint of the
virtual link, though they may traverse multiple routing devices. To configure a
G8264CS as one endpoint of a virtual link, use the following command:
RS 8264CS(config-router-ospf)# area-virtual-link <link number>
neighbor-router <router ID>
where <link number> is a value between 1 and 3, <area index> is the OSPF area index
of the transit area, and <router ID> is the router ID of the virtual neighbor, the
routing device at the target endpoint. Another router ID is needed when
configuring a virtual link in the other direction. To provide the G8264CS with a
router ID, see the following section Router ID.
For a detailed configuration example on Virtual Links, see "Example 2: Virtual
Links" on page 486.
Routing devices in OSPF areas are identified by a router ID. The router ID is
expressed in IP address format. The IP address of the router ID is not required to be
included in any IP interface range or in any OSPF area, and may even use the
G8264CS loopback interface.
The router ID can be configured in one of the following two ways:
 Dynamically—OSPF protocol configures the lowest IP interface IP address as the
router ID (loopback interface has priority over the IP interface). This is the
default.
 Statically—Use the following command to manually configure the router ID:
RS 8264CS(config-router-ospf)# ip router-id <IPv4 address>
If there is a loopback interface, its IP address is always preferred as the router
ID, instead of an IP interface address. The ip router-id command is the
preferred method to set the router ID and it is always used in preference to the
other methods.
 To modify the router ID from static to dynamic, set the router ID to 0.0.0.0 and
re‐initialize the OSPF process.
 To view the router ID, use the following command:
RS 8264CS(config-router-ospf)# show ip ospf