From: Hyunseog Ryu (r.hyunseog@ieee.org)
Date: Thu Aug 02 2007 - 09:42:02 ART
It depends.
Some ISPs are doing active filtering based on ARIN or other RIR's
minimum allocation size, but others don't.
So the network, which applies filtering, may do not know specific /24
or something like that, then the traffic for that network may follow
upstream provider's /20 or larger block announcement until it see
specific network routing.
But normally it is not a big problem.
I don't see anybody is changing origin code at this moment.
It's possible, but there is no reason to do that.
Maybe for BGP community values and AS path prepending. But not for
Origin code.
Hyun
Alex Steer wrote:
> Hyun
>
> Would your address space more than likely get aggregated with all there
> other customers / there own addressing?
>
> Is it possible that they would change the origin code at this point?
>
> Cheers
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Hyunseog Ryu
> Sent: 29 July 2007 21:29
> To: Gregory Gombas
> Cc: Herbert Maosa; Group study
> Subject: Re: Unique AS number when connecting to two different ISP's?
>
> 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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