"We also had problems where transit customers said don't want to be
exported to a certain IX point of presence while he wanted to be
exported at a different location."
That's a fairly normal request. I think nearly every major IP transit
provider has built out a BGP action community system to allow their
customers to control prefix announcements in the way you're describing
it here (e.g. prepending and no-export to certain peers/upstreams). Of
course outbound traffic from your customer to "the rest of the world"
can not be controlled that way.
Best regards,
Martijn
Hi Martjin,
I think nearly every major IP transit provider has built out a BGP action community system to allow their customers to control prefix announcements in
That’s also what I thought but the truth is: there are MANY major transit providers who simply doesn't support any community ... one of the most famous is Hurricane Electric 
Jürgen Jaritsch
Head of Network & Infrastructure
ANEXIA Internetdienstleistungs GmbH
Telefon: +43-5-0556-300
Telefax: +43-5-0556-500
E-Mail: JJaritsch@anexia-it.com
Web: http://www.anexia-it.com
Anschrift Hauptsitz Klagenfurt: Feldkirchnerstraße 140, 9020 Klagenfurt
Geschäftsführer: Alexander Windbichler
Firmenbuch: FN 289918a | Gerichtsstand: Klagenfurt | UID-Nummer: AT U63216601
HE will if you know who to speak to...
Regards,
Dovid
Hi Dovid,
Yes, vitamin B often helps. But it doesn't matter - if the transit provider doesn't support it on an official way you do net get an SLA for the communities. They could stop working from one day to another ...
Jürgen Jaritsch
Head of Network & Infrastructure
ANEXIA Internetdienstleistungs GmbH
Telefon: +43-5-0556-300
Telefax: +43-5-0556-500
E-Mail: JJaritsch@anexia-it.com
Web: http://www.anexia-it.com
Anschrift Hauptsitz Klagenfurt: Feldkirchnerstraße 140, 9020 Klagenfurt
Geschäftsführer: Alexander Windbichler
Firmenbuch: FN 289918a | Gerichtsstand: Klagenfurt | UID-Nummer: AT U63216601
Hi Jürgen,
Well, I did say "nearly" every major IP transit provider.. 
If BGP action communities are important to your network and your
existing upstream(s) don't support them, then maybe it is time to start
looking for a different transit provider.
Best regards,
Martijn