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BGDS
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Transit and IX problem

Sat Feb 23, 2019 6:02 pm

my router CCR1072 i want help bgp to mikrotik we now have 1G cogent transit and 10G netix internet exchange.

The problem is that the traffic going through the constant cogent is not going to go one way from the other.

I would like you to help me.
 
christopherh
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Re: Transit and IX problem

Sun Feb 24, 2019 9:25 am

Hello BGDS,

If I understand your question correctly, your router is routing all your traffic out via Cogent and not using the NetIX connection?

Based on the Hurricane Electric BGP Lookup (https://bgp.he.net/AS209702), you currently have a BGP peering session with both NetIX and Cogent. There are a few questions:
  • Are you taking a full table from Cogent and exporting your RIPE-assigned prefixes to both Cogent and NetIX?
  • How have you configured your export and import route filters?
It sounds like your filters aren't configured correctly. Do you have a looking glass configured that I can use to take a look at the routes being sent and received? If you want some hands-on help configuring your router, feel free to send me a private message.
 
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BGDS
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Re: Transit and IX problem

Fri Mar 01, 2019 9:43 pm

how send this forum private message i don't find please add me skype sayfanet_ozkan or +905442062222 whatsup

Hello BGDS,

If I understand your question correctly, your router is routing all your traffic out via Cogent and not using the NetIX connection?

Based on the Hurricane Electric BGP Lookup (https://bgp.he.net/AS209702), you currently have a BGP peering session with both NetIX and Cogent. There are a few questions:
  • Are you taking a full table from Cogent and exporting your RIPE-assigned prefixes to both Cogent and NetIX?
  • How have you configured your export and import route filters?
It sounds like your filters aren't configured correctly. Do you have a looking glass configured that I can use to take a look at the routes being sent and received? If you want some hands-on help configuring your router, feel free to send me a private message.
 
joegoldman
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Re: Transit and IX problem

Fri Mar 01, 2019 11:41 pm

Best guess is you are importing routes from both, but because your cogent routers are older they are preferred (i.e. that bgp session came up first). I would set a BGP Local Pref on the IX routes only.

If this is for inbound traffic only going via cogent, then make sure you are advertising your ranges right to the IX, use their looking glass if they have one. Another suggestion is to advertise smaller prefixes to the IX (so if you had a /22, advertise /22 to cogent but 2x /23's to IX) to ensure those listening on the IX prefer your IX routes more.
 
bbs2web
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Re: Transit and IX problem

Sat Mar 02, 2019 7:54 am

Also ensure your Cogent and IX peers are associated with the same BGP instance, multiple instances are when you need totally separate BGP for isolated VRFs.
 
christopherh
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Re: Transit and IX problem

Sun Mar 03, 2019 1:36 pm

Another suggestion is to advertise smaller prefixes to the IX (so if you had a /22, advertise /22 to cogent but 2x /23's to IX) to ensure those listening on the IX prefer your IX routes more.
This would have to be one of the worst ways to "force" carriers to prefer a certain route. There are other ways to achieve what they are looking for.

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