On Jan 17, 2011, at 12:32 AM, Michel de Nostredame wrote: > On Fri, Jan 14, 2011 at 12:30 PM, Patrick W. Gilmore <patr...@ianai.net> > wrote: >> On Jan 14, 2011, at 11:03 AM, Michel de Nostredame wrote: >>> On Fri, Jan 14, 2011 at 3:33 AM, Bogdan <shos...@shoshon.ro> wrote: >>>> allowas-in will do the trick >>> Provided your uplink ISP does not filter out that. >> Why would your upstream filter that out? >> I would get a new upstream if they do. > > According to Juniper junos document, > > "BGP checks whether the neighboring AS matches the AS of the external > peer to which the router is advertising. If there is a match, the > route advertisement is suppressed. Advertisement suppression is > enabled by default for BGP peers configured in non-VPN routing and > forwarding (VRF) instances, including the master instance."
I do not think that paragraph means what you think it means. I've seen my own AS in full tables from upstreams using Juniper routers many times. -- TTFN, patrick > We may not able to assume all ISP willing to or by-default add > "advertise-peer-as" into configuration if they use a Juniper router. > Also we may not able to assume ISP will not put a policy/route-map to > prevent route been advertised to the same AS. > > If there is a need to use single-AS in multiple sites and these sites > need to communicate each other via Internet ISP, statically route > traffic to Internet (or a default route to Internet) would be safer. > > If there is a need on this kind of communication, or the communication > been done via a tunnel with both sides using ISP's IP (interface IP) > as tunnel source, then there should have no risk to use single-AS in > multiple sites in terms of connectivity. > > -- > Michel~ >
