Reference Guide

Link State ID Displays the Link State ID.
Advertising
Router
Identifies the router ID of the LSA’s originating router.
LS Seq Number Identifies the link state sequence number. This number
enables you to identify old or duplicate LSAs.
Checksum Displays the Fletcher checksum of the an LSA’s complete
contents.
Length Displays the length in bytes of the LSA.
Network Mask Displays the network mask implemented on the area.
Metrics Type Displays the external type.
TOS Displays the Type of Service (TOS) options. Option 0 is the
only option.
Metric Displays the LSA metric.
Forward
Address
Identifies the address of the forwarding router. Data traffic is
forwarded to this router. If the forwarding address is 0.0.0.0,
data traffic is forwarded to the originating router.
External Route
Tag
Displays the 32-bit field attached to each external route. This
field is not used by the OSPF protocol, but can be used for
external route management.
Example
Dell#show ip ospf 1 database external
OSPF Router with ID (20.20.20.5) (Process ID 1)
Type-5 AS External
LS age: 612
Options: (No TOS-capability, No DC, E)
LS type: Type-5 AS External
Link State ID: 12.12.12.2
Advertising Router: 20.31.3.1
LS Seq Number: 0x80000007
Checksum: 0x4cde
Length: 36
Network Mask: /32
Metrics Type: 2
TOS: 0
Metrics: 25
Forward Address: 0.0.0.0
External Route Tag: 43
LS age: 1868
Options: (No TOS-capability, DC)
LS type: Type-5 AS External
Link State ID: 24.216.12.0
Advertising Router: 20.20.20.8
LS Seq Number: 0x80000005
Checksum: 0xa00e
Length: 36
Network Mask: /24
Metrics Type: 2
TOS: 0
1010
Open Shortest Path First (OSPFv2)