From: sheherezada@gmail.com
Date: Thu Aug 02 2007 - 11:16:41 ART
Oh, and if you want to influence the incoming traffic (you want to
prepend), you can arrange with your ISP and announce your prefixes
with a specific community. They will prepend their ASN for you and
you are set.
Mihai
On 8/2/07, sheherezada@gmail.com <sheherezada@gmail.com> wrote:
> Not really necessary. You can use a private ASN even when multihoming
> with two different providers and even if announcing some [provider
> independent] prefixes. They will just strip your private ASN when
> announcing your prefixes to the outside world.
>
> You need your public AS number only if you want to express a
> particular routing policy, i.e. you do have a particular preference as
> to which of the upstream providers should be used for incoming
> traffic. Otherwise, there is absolutely no problem for the outside
> world to see that the prefix appears to be originated from different
> ASs.
>
> Mihai Dumitru
> CCIE #16616
>
> P.S. And I know a person who had a public ASN and PI address space for
> his own personal use - it's not me :)
>
>
> On 7/29/07, Hyunseog Ryu <r.hyunseog@ieee.org> wrote:
> > Upstream providers will remove private AS number when they readvertise
> > to other ISPs.
> > So natually if you have multi-homed to multiple ISPs, the route will be
> > appeared as inconsistent ORIGIN AS, which will not appeared as valid
> > route from RFC viewpoint.
> > According to RFC - I don't remember which -, it should be originated
> > from single AS number.
> > Also, customer who uses Private ASN with multiple upstream providers can
> > NOT implement consistent routing policy for that matter.
> > So multihomed customer with private ASN is not recommended for multiple
> > providers upstream connection.
> > If customer have multiple connections with SAME providers, they may use
> > private ASN for load sharing purpose.
> >
> > Hyun
> >
> >
> > Gregory Gombas wrote:
> > > What are you losing by using a private ASN? You can still advertise
> > > your own dedicated IP address space via both providers can't you? Your
> > > ISP's simply needs to remove that private AS when passing the update
> > > to other ISP's...
> > >
> > > Am I missing something here?
> > >
> > > On 7/29/07, Herbert Maosa <asawilunda@googlemail.com> wrote:
> > >
> > >> If you dont have your own ASN, you will most likely have to use a private
> > >> ASN to connect to the two ISPs. Remember that if you use the ISPs ASN then
> > >> you are an extension of that ISP. Using the private ASN in this case will
> > >> permit you to be totally provider independent.
> > >>
> > >> regards,
> > >>
> > >> Herbert.
> > >>
> > >>
> > >> On 7/29/07, Gregory Gombas <ggombas@gmail.com> wrote:
> > >>
> > >>> When connecting to the internet via two different ISP's, why is it
> > >>> necessary to have a unique AS?
> > >>>
> > >>> What if you simply configured your BGP router with the same AS number
> > >>> as one of your ISP's?
> > >>>
> > >>> Considering there are only 64511 unique AS numbers, I assume that most
> > >>> if not all the AS numbers are already taken. What do companies do in
> > >>> the case they cannot get their own AS number and need to multihome?
> > >>>
> > >>> Thanks,
> > >>> Greg
> > >>>
> > >>>
> > >>>
> > >> _______________________________________________________________________
> > >>
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> > >>>
> > >>>
> > >>
> > >> --
> > >> Kindest regards,
> > >> hm
> > >>
> > >
> > > _______________________________________________________________________
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> >
> > _______________________________________________________________________
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