hi,
i have a cisco sg300-28 switch
and i have two separate wan connections - one 3Mbps and the other 2Mbps both from different ISPs

i want to perform linik aggregation on them
1) to increase bandwidth
2) to provide failover
3) load balancing

if i do link aggregation oer the switch ( using its web interface) it provides failover but not bandwidth aggregation...
how do i attain bandwidth aggregation...

is there a way i can do it using linux and not relying on the switch for that
i can get a 2/4 port NIC server for that if need be....but i will also be running my proxy, dns and dhcp server on that ...probably VPN as well

any suggestions ?

Can't be done...

The best you can do is send some traffic over one connection, and other over the second. This way you use both and under ideal conditions might be able to get overall throughput of 5Mbps. You will not be able to download a movie at 5Mbps though - it is a single connection and it will be limited to the speed of the actual connection it is using.