As far as I know they both do the same thing pretty much
For the first two statements, interfaces with the exact addresses of 10.10.10.1 and 10.10.20.1 are put in area 0, while for the last two statements, interfaces with an address of 10.10.10.x (so 10.10.10.1,.2.3,etc) and 10.10.20.x (so 10.10.20.1,.2.3,etc) are put in area 0.
hope this helps
"...you are never too old to learn" anon
Last Edit: 3 years 11 months ago by skylimit. Reason: better wording of reply
The administrator has disabled public write access.