[c-nsp] BGP blackhole community config

Satish Patel satish.txt at gmail.com
Sun Jun 19 22:07:58 EDT 2016


I have added "ip bgp-community new-format" in global config, but i
don't have following command in my ASR1006 router

neighbor xx.xx.xx.xx remote-as 200 send-community

so i have added

neighbor xx.xx.xx.xx send-community


Still not working :(  do i need to add 192.0.2.1 IP in my route map ?

On Sun, Jun 19, 2016 at 9:06 PM, Rich Davies <rich.davies at gmail.com> wrote:
> config term
> !
> ip bgp-community new-format
> !
> router bgp 100
>  neighbor xx.xx.xx.xx remote-as 200 send-community
> !
> end
>
>
> Try that and clear your BGP session.   Based on fact you have no "network"
> statements to announce directly in BGP you are instead redistributing static
> routes into BGP to be announced.   I believe you need to add the "ip
> bgp-community new-format" to your global configuration and in addition tell
> your neighbor statement to "send-community".
>
> BGP community is an optional transitive attribute its only sent to external
> ASN if you tell it to.
>
>
> More on communities indicating they are (optional) transitive attributes:
> http://www.cisco.com/c/en/us/about/press/internet-protocol-journal/back-issues/table-contents-24/bgp-communities.html
>
> On Sun, Jun 19, 2016 at 7:37 PM, Satish Patel <satish.txt at gmail.com> wrote:
>>
>> We have setup new BGP configuration with ISP and ISP has been told
>> send community "64682:0" for blackholing. I am new in BGP.
>>
>> I was reading BGP community format is ASN:NN but my ISP ASN number
>> isn't 64682 so i am assuming they gave me example (64682:0)
>>
>> This is what i configure in my router.
>>
>> router bgp 100
>>  bgp log-neighbor-changes
>>  redistribute static route-map RTBH
>>  neighbor xx.xx.xx.xx remote-as 200
>>
>>
>> route-map RTBH permit 10
>>  match tag 666
>>  set community <ISP_ASN>:666
>>
>> route-map RTBH permit 20
>>
>>
>> I have send following null route but it didn't work :(
>>
>> ip route xx.x.x.xx 255.255.255.255 Null0 tag 666
>>
>>
>> what i am doing wrong? how do i use community to send blackhole route?
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>
>


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