Monday, May 3, 2021

Wildcard masks and ACLs

So I thought I had a pretty strong grasp of wildcard masking until a few odd examples came my way.

Pretty much I always used the idea of evaluating the subnet mask range. So if I saw a range of 10.2.3.0 /28 I'd know the wildcard would be 0.0.0.15 because /28 produces a range of 16 (-1). However when running through some Boson tests I was sort of flummoxed with the prospect of a 0.0.0.254 (or anything above .191). Then I had an instructor advise to just run the binary.

why? if it's a .127 or below, seems straightforward. what am i not understanding with the 191+ on a wildcard? Seems that's when split matches start occuring - past my 'up to .127' method... I guess. uhg.



No comments:

Post a Comment