Dear sir:please have a look at this kind of products:

product feature:
-- Compliant with IEEEE 802.3,802.3u and 802.3x standard;
-- 24 10/100 Mbps Auto-suitable RJ-45 ports;
-- 1 expansion slot;
-- 12K Media Access Control (MAC) addresses;
-- 6M-packet buffer memory architecture shared by all ports;