Router Id; Authentication - Lenovo Flex System Fabric CN4093 Application Manual

Router ID

Authentication

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Routing devices in OSPF areas are identified by a router ID, expressed in IP
address format. The router ID is not required to be part of any IP interface range or
in any OSPF area, and may even use the CN4093 loopback interface (see
"Loopback Interfaces in OSPF" on page
The router ID can be configured in one of the following two ways:
 Dynamically (the default)—OSPF protocol configures the router ID as the lowest
IP loopback interface IP address, if available, or else the lowest IP interface IP
address, if available. Once dynamically configured, the router ID does not nor‐
mally undergo further updates.
 Statically—Use the following command to manually configure the router ID:
CN4093(config­router­ospf)# ip router­id <IPv4 address>
To change the router ID from static to dynamic, set the router ID to 0.0.0.0, save the
configuration, and reboot the CN4093. To view the router ID, enter:
CN4093(config­router­ospf)# show ip ospf
OSPF protocol exchanges can be authenticated so that only trusted routing devices
can participate. This ensures less processing on routing devices that are not
listening to OSPF packets.
OSPF allows packet authentication and uses IP multicast when sending and
receiving packets. Routers participate in routing domains based on pre‐defined
passwords. Lenovo N/OS supports simple password (type 1 plain text passwords)
and MD5 cryptographic authentication. This type of authentication allows a
password to be configured per area.
We strongly recommend that you implement MD5 cryptographic authentication as
a best practice.
Figure shows authentication configured for area 0 with the password test.
Simple authentication is also configured for the virtual link between area 2 and
area 0. Area 1 is not configured for OSPF authentication.
436).
Chapter 31: OSPF
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