Finding asymmetric path

Randy Bush randy at
Fri Nov 27 22:23:53 CST 2009

>>> I'm reasonable certain a customer of ours who is using one of our 
>>> netblocks is using a different reverse path to reach us.  How might I 
>>> figure out who is allowing them to source traffic from IPs that belong 
>>> to us?
>> you are implying that they are not allowed to multi-home using the ip
>> space you have assigned to them.  good way to lose a customer.
> Does it count as multihoming when we are the only ones announcing the
> space?

almost an interesting question.  but i think it is playing with words.
if i understand your original statement, they are clearly attached to at
least two providers.

perhaps it is fear of what they, possibly mistakenly, perceive to be
your policy regarding announcement of space that keeps them from
announcing normally to both, or more, links?


More information about the NANOG mailing list