Increasing OSPF Network Statement

[TrivialPants]

Hi All,

I want to increase the size of my OSPF listening network. Is it possible to just add a new network statement without taking down the existing network? Or should I expect the OSPF to recalculate and expect flapping/network outages as soon as the changes are made? 

I have about 20 OSPF network links that I will have to update this on, and I want to increase from the /26 to a /25. Is it possible to just do this asynchronously? 

router ospf 100
 router-id <router ID>
 network 192.168.2.0 0.0.0.63 area 0

to this:

router ospf 100
 router-id <router ID>
 network 192.168.2.0 0.0.0.127 area 0

reference: https://www.pearsonitcertification.com/articles/article.aspx?p=1868078

[MHM Cisco World]

sure you can 
the Net command under OPSF use as guide for OSPF, 
it inform OSPF check all interface whcih interface within this subnet will enter in OSPF adj. 

[Joseph W. Doherty]

I believe it very unlikely you'll impact your existing network by either adding the /25 (including if replacing the /26).

OSPF will recalculate the area zero topology as each new network is added to the topology.  Again, though, I think it unlikely you'll impact your existing network.  (Reason I say "unlikely" because I don't know what your existing topology is, what you're changing it to, or how stable the existing or "to be" network is.  I.e. it's possible, you could have an impact, but once again, probably unlikely.)