Re: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)

"Jakob Heitz (jheitz)" <> Sun, 06 November 2016 05:43 UTC

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From: "Jakob Heitz (jheitz)" <>
To: heasley <>
Thread-Topic: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)
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Date: Sun, 6 Nov 2016 05:43:42 +0000
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Subject: Re: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)
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It does not change my opinion. My opinion is that we should filter by default at the EBGP boundary. IOS-XR does that. Cisco recognized the problem addressed by draft-grow-bgp-reject back when IOS-XR was designed. Unfortunately, it was too late to change the default in IOS. If IOS changes that default, it would break many existing deployments.


> On Nov 5, 2016, at 9:08 PM, heasley <> wrote:
> Sat, Nov 05, 2016 at 11:13:46PM +0000, Jakob Heitz (jheitz):
>> IOS-XR does not send communities or extended communities to eBGP neighbors by default.
>> To send communities, you need to configure
>>  send-community-ebgp
>> Under the neighbor address-family.
>> To send extended communities, you need to configure
>>  send-extended-community-ebgp
>> The reason is that many operators use communities internal to an AS for many reasons and we don't want these to accidentally leak out to the wider internet. If an operator intends to send communities outside of their own AS, then they need to make a conscious decision to do so. Along with that conscious decision, they should filter out all the internally used communities in a route-policy.
>> In my large-community code, I have lumped them under send-community-ebgp. At this point, I am very open to suggestions for configuration. Once the code is released, it gets much harder to change configs.
> If you consider draft-grow-bgp-reject, does that change your opinion about
> filtering needing to be the default?