The assumption that your initial allocation of address space is going to be a /20 is probably incorrect. Allocation of address space is based on a slow start procedure outlined in RFC2050. What usually happens is that you request enough address space to be at 50% immediate utilization and 80% utilization within 3 months. To receive a contiguous /20 will probably require multiple IP requests and plenty of renumbering. =P t Charles Smith wrote:
Please consider the following scenario:
A new company wants to become a regional ISP. This company will purchase one or two large bandwidth circuits from a NSP of their choice.
Then the new regional ISP will offer private line p2p Internet service to regional businesses. Basically, this is a small operation.
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially.
Furthermore, I assume the NSP would provide the regional ISP with a supernet - say a /20 or so. Then the regional ISP would allocate subnets of the supernet to their customer - say /24s.
I also assume the regional ISP would not require an AS number since they are not implementing BGP. Basically, all traffic from the regional ISP and customers is default routed to the single upstream connection.
Are these assumptions valid? Is this a good configuration? I realize multiple upstreams from different providers is optimal, however not plausdable in this case.
Your constructive insight to the scenario is appreciated.
Chas _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com
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