[j-nsp] Dealing with multihomed customer BGP primary/backup links

[Mark Tinka]

On 13/Jul/16 10:36, Cydon Satyr wrote:

> What would be the optimal way to deal with following scenario.
>
> The customer of ours has a primary bgp connection over primary link on one
> router, and a backup bgp connection (up) on backup link on our other
> router. The customer may or may not (usually not) terminate both
> primary/backup links on the same router.
>
> We want to stop customer using backup link at all as long as the primary
> link is up. Since we police both primary and backup link, customer can just
> load balance and use both links.
>
> Without asking changes on his side (so something link MC-LAG won't fit
> here, I guess?), what are way to deal with this.
>
> I can think of making a script which will not import their routes as links
> a primary link route is in our table.
>
> The bgp conditional policy doesn't work for importing routes, only
> exporting... so that won't work either.
>
> Any other suggestions maybe?

I know this may not answer your question, but this is why we don't sell
active/backup services to customers.

We sell active/active, and it's the customer's responsibility to control
which link has traffic. We solve the issue commercially, incentivizing
the customer to self-control or pay up. Works well.

Active/backup scenarios work best if you can control the CPE, i.e., a
managed service. Without that, best never to trust the customer to
honour anything.

Mark.