* Does BGP require two similar sized links for load balancing. Could I use an Serial T1 and a cable line to do BGP.
You can use two different link speeds, but chances are you can't use a cable link. I have never heard of a service provider supporting that. Typically the link speed up/down are the same (ie T1, frac T3).
* What are the advantages and disadvantages in BGP when terminating all ISP lines in one router and each ISP line in a separate router (Does it have anything to do with load sharing)
Nothing to do with load sharing, but everything to do with redundancy. If you have two redundant connections on one router and that router fails, neither line will be active. Having each line on a separate router provides router redundancy in case of failure.
* Could someone let me know about "inbound" load sharing in BGP. I can understand about redundancy but still have confusion on inbound load sharing
When you advertise your address space via BGP you tell the other routers that your equally available through ISP1 or ISP2. It really isn't load sharing but it's as close as you'll get.
* Does BGP requires continuous monitoring or is it like once setup we are good to go.
It's like all other routing protocols. You should proactively monitor it to make sure it is running properly and doing what you want it to.
* Is it very hard to obtain BGP skills.
Not really, a lot of lab time will get you the skills. The hard part is getting real world experience. That's where you'll really learn about BGP.
HTH and please rate.
