Dividir cadena usando la declaración sql (dirección IP)

Puede usar la función PARSENAME de la siguiente manera:

with address as(
select '192.168.1.1' as IpAddress
Union
select '192.168.1.2' as IpAddress
Union
select '192.168.1.3' as IpAddress
)
SELECT PARSENAME(IpAddress,4) as first, 
   PARSENAME(IpAddress,3) as second,
   PARSENAME(IpAddress,2) as third,
   PARSENAME(IpAddress,1) as fourth,
FROM address

La función PARSENAME devuelve la parte especificada de un nombre de objeto.