nanog mailing list archives

Re: the route is not in our bgprouter


From: Deric Kwok <deric.kwok2000 () gmail com>
Date: Tue, 25 Oct 2011 21:49:05 -0400

Hi

Our upstream provider said that destination network is blocking our ip.

Now my question is how we can know it

If this network is blocking us, the traceroute should reach out our
bgp router to go further nodes before that network, right

2nd question is how they block us to not allow the route to advertise
from our upstream to our bgp router.
ls it possible?

Thank you so much



On Tue, Oct 25, 2011 at 9:35 AM, Patrick Sumby
<patrick.sumby () sohonet co uk> wrote:
If your provider has a looking glass then that is a good start to see if
they have the route in their routing tables. http://www.traceroute.org/ is a
good start for searching for a looking glass on their website.

Have you checked to see if you're actually recieving the route? You may be
getting the route but not installing it into your routing table for some
reason (eg invalid next hop or a router from another provider is being
prefered). Do you have prefix lists inbound from your provider that could be
blocking a route?

show ip route X.X.X.X
and
show ip bgp route X.X.X.X

will give different information.

If you've covered the above and not found the answer then try talking to
your provider.

Regards
Patrick


On 25/10/2011 13:26, Deric Kwok wrote:

Hi

When we try to reach to outside ip, this route doesn't have in our bgp
router

How can we check whether it doesn't advertise from our upstream to us?

Any web site and tools can help?

Thank you






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