The following output exists on Router R1, a router internal to area 1. What can you
determine as true from the output of the show ip ospf database summary command?
Routing Bit Set on this LSA
LS age: 124
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links (Network)
Link State ID: 10.1.0.0 (summary Network Number)
Advertising Router: 1.1.1.1
LS Seq Number: 80000001
Checksum: 0x878F
Length: 28
Network Mask: /22
TOS: 0 Metric: 11
A.
The LSA was created by an ABR due to an area range command.
B.
The LSA was created by an ASBR due to a summary-address command.
C.
If created by an area range command, the best metric for a subordinate subnet on that
ABR must have been 11.
D.
None of the other answers is correct.
Explanation:
The show ip ospf database summary command lists only Type 3 LSAs. The summaryaddress command creates Type 5 LSAs on ASBRs, ruling out one answer.
The output does not specify whether the LSA was created as a summary route; all
references to the word “summary” refer to Type 3 Summary LSAs. If created by an area
range command, the metric defaults to be the best metric of all subordinate subnets, but it
may also be explicitly set, ruling out another of the possible answers. In short, this LSA may
represent a route summarized by the area range command, but that fact cannot be proved
or disproved by the output as shown..