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

On Tue, Oct 25, 2011 at 9:49 PM, Deric Kwok<deric.kwok2000@gmail.com> wrote:

...

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

Now my question is how we can know it

you can't really, if they do things right. (Aside from just not getting there)

Have you tried contacting the destination network. I assume you have a customer that wants to talk to their customer? Its in both your interests to see why things aren't working.

...

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

presumably, unless the destination is a direct peer.

...

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

probably they just don't accept your route... why do you think your route isn't propogated beyond your border(s)?

What is your prefix that you're announcing? Is it from a new range an potentially bogon filtered somehwere? What is the destination you're trying to get to? What do you see in BGP looking glasses for that IP. They could be doing something stupid/evil like putting your AS in their path.

...

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