"jf" wrote...
For example I have:
172.21.34.82
172.21.48.80
172.21.48.83
172.22.42.100
172.22.42.101
172.24.10.15
172.24.10.16
172.24.102.12
172.24.14.15
....

As those with a very slight understanding of what IP addresses are might
have noticed from this sample (and should have known before responding),
octets should be treated as numbers. Therefore, the 2nd to last IP address
with 3rd octet 102 should be sorted last (in ascending order), not 3rd,
which it would be with simplistic text parsing.

What you need is to pull the 3rd octets into a separate column AS NUMBERS,
and sort on that column. The general way to isolate the 3rd octet in x is
with a formula like

=INT(--MID(x,FIND(CHAR(127),SUBSTITUTE(x,".",CHAR(127),2) )+1,3))