I finally got an excellent answer from a co-worker...
For some flavors of sql, use "split_part" along with host(inet) to get the text field.
select split_part(host('101.255.30.40'::inet), '.', 1);
select split_part(host('101.255.30.40'::inet), '.', 2);
select split_part(host('101.255.30.40'::inet), '.', 3);
select split_part(host('101.255.30.40'::inet), '.', 4);
results in
101
255
30
40
If you want to get trickier and handle IPv6, use a mask to speed up the operation along with case statements to get the IP version:
select
(case
when family('101.255.30.40'::inet) = 4 then split_part(host(broadcast(set_masklen('101.255.30.40'::inet, 32))), '.', 4)::varchar
when family('101.255.30.40'::inet) = 6 then split_part(host(broadcast(set_masklen('101.255.30.40'::inet, 64))), ':', 4)::varchar
else null end)::varchar as octet4;
select
(case
when family('2604:8f00:4:80b0:3925:c69c:458:3f7b'::inet) = 4 then split_part(host(broadcast(set_masklen('2604:8f00:4:80b0:3925:c69c:458:3f7b'::inet, 32))), '.', 4)::varchar
when family('2604:8f00:4:80b0:3925:c69c:458:3f7b'::inet) = 6 then split_part(host(broadcast(set_masklen('2604:8f00:4:80b0:3925:c69c:458:3f7b'::inet, 64))), ':', 4)::varchar
else null end)::varchar as octet4;
results in
40
80b0
you can then add in a hex-to-int conversion into the case statement if you want to cast the IPv6 as a number instead.