Ipv6 Routing (from hell)

[Bernhard Schmidt]

Hi Nick,

> Michael, you really need to get your own ipv6 address range, get an ASN 
> and talk BGP.  You can do cute and interesting things and have multiple 
> access points from your network into multiple upstreams.  Yeah, you can 
> fudge around with tunnels and build brokenness into your network from 
> day 1, but trust me, you'll regret it.

Those networks usually suffer from a lack of internal bandwidth, so you 
really need optimized ingress routing as well. Impossible to do without 
further deaggregation (down to having each endsite (=/64) announced on 
the closest ingress), which pollutes the routing table even more.

Folks are debating about giving such networks one routing slot already 
(see the PI discussions), doing PI and BGP on those networks either 
results in internal congestion (announcing a /48 on all ingress points 
and forwarding the traffic all the way through the mesh to the 
destination) or deaggregating to possibly hundreds of routing slots for 
optimized ingress in reasonably sized networks.

And remind you, we are usually talking about dozens of el-cheapo 20 EUR 
consumer DSL connections to different ISPs in those meshing networks, 
there is just no way of getting native IPv6 with BGP on there.

PI+BGP is a good tool for most multihoming purposes, but not for all of 
them.

Bernhard