Multi-homing with multiple ASNs

joel jaeggli joelja at
Sun Nov 23 19:20:52 UTC 2014

On 11/21/14 1:07 AM, Mark Tinka wrote:
> On Friday, November 21, 2014 12:00:47 AM Curtis L. Parish 
> wrote:
>> We have recently added a second ISP  (third if you count
>> I2).  Our first "ISP" is actually a private state
>> network that peers with two Tier 1 providers.  We own an
>> AS number and our IP space but at the last minute
>> learned our state network is advertising our network
>> using two different ASNs (neither ours) so they can load
>> balance their connections.    If you hit the right
>> looking glass server you can see our network advertised
>> by three different ASNs.    We were told by the new ISP
>> that this is a problem but the state network says it is
>> not.
>> Looking for opinions and words of wisdom on this split
>> advertising issue.
> Why aren't you originating your own prefixes and ASN by 
> yourselves, since you own both?

The practical problem here is that the control of prefix origination is
distributed. so if there is a need to withdraw it from the state network
or advertise it no export for some reason (e.g. performance problem
maintenance etc) you likely can't. Their grasp of load-balancing seems a
bit shallow also.

> Mark.

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