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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: IP over SONET considered harmful?
Scott Brim wrote: | For example, in order for TTL to be effective, not every node needs to | decrement it -- we just need to be sure that no loops can form where it | doesn't get decremented. Yes, but you also want to make sure that the price-per-packet is really really really close to zero in the "gap" between ttl decrementing routers, otherwise, even though a loop may never form in the non-ttl-decrementing fabric, it may form across it, for example, between the two routers on either side of the gap, or through the two routers on either side of the gap. If the "gap" is a sub-IP fabric a continent and an ocean wide, such a loop tends to be somewhat expensive. TTL decrementing as a loop mitigation feature ought to be fairly popular in such circumstances. Sean.
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