--> 测试数据: #T
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (ip varchar(13),num int)
insert into #T
select '192.168.0.1',1 union all
select '192.168.0.106',1 union all
select '192.168.1.116',1 union all
select '192.168.2.116',1 union all
select '61.125.137.5',1 union all
select '61.125.1.5',1

select parsename(ip,4)+'.'+parsename(ip,3)+'.*.*' as ip, count(*) as n from #T group by parsename(ip,4)+'.'+parsename(ip,3)+'.*.*'

/*
ip          n
----------- -----------
192.168.*.*    4
61.125.*.*    2
*/

declare @t table (s_ip varchar(100))

insert @t select
'192.168.0.1'    union all select
'192.168.0.106'    union all select
'192.168.1.116'    union all select
'192.168.2.116'    union all select

'61.125.137.5'    union all select
'61.125.1.5 1'


select PARSENAME(s_ip,4)+'.'+PARSENAME(s_ip,3)+'.*.*' as s_ip ,count(*)  as n from @t
 group by  PARSENAME(s_ip,4)+'.'+PARSENAME(s_ip,3)+'.*.*'

--结果 
s_ip                                                                                                                                                                                                                                                             n           
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------- 
192.168.*.*                                                                                                                                                                                                                                                      4
61.125.*.*                                                                                                                                                                                                                                                       2

（所影响的行数为 2 行）

--> 测试数据: #T
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (IP varchar(13),c2 int)
insert into #T
select '192.168.0.1',1 union all
select '192.168.0.106',1 union all
select '192.168.1.116',1 union all
select '192.168.2.116',1 union all
select '61.125.137.5',1 union all
select '61.125.1.5',1
go
select left(IP,charindex('.',IP,charindex('.',IP)+1))+'*.*',count(*) cnt
from #T
group by left(IP,charindex('.',IP,charindex('.',IP)+1))+'*.*'
go
drop table #T

/*
                 cnt         
---------------- ----------- 
192.168.*.*      4
61.125.*.*       2

（所影响的行数为 2 行）

*/