I have an ADSL type internet connection with static IP using 4-port Belkin modem. This internet connection is being shared using Cisco Small Business manageable switch with 48 ports. I am also taking two separate connections from other 2 ports of the Belkin modem. In all, three LAN ports of Belkin modem are being occupied (one is going to Cisco switch and the other two are going to other two PCs). Everything is working fine except when the internet is down! So, I have purchased another internet connection from different ISP. This connection is DSL with username/password with static IP. Now, what I am asked to do is have this new connection(DSL type) shared between two PCs which earlier was being done from Belkin modem, so now, only ADSL type internet connection is to be shared using Cisco Switch. Also, what should I do such that when DSL is down I should be able to access internet using adsl type connection? I have also got d-link dwr-113 router.
I am complete newbie to networking and I have tried my best to explain my scenario.
The easiest solution is a dual WAN load balancing router with failover. Both ISP modems will attach to the same router and from there go to the switch. Cisco has several models, take a look at the column along the left on this page for models: http://www.cisco.com/en/US/products/ps12262/index.html