1GE L3 aggregation

Sat Jun 18 19:31:37 UTC 2016

On 18 June 2016 at 13:07, Mark Tinka <mark.tinka at seacom.mu> wrote:

> > Our PoPs are connected in a ring topology (actually multiple rings). If a
> > link goes down somewhere, or an intermediate device crashes, the L2VPN
> will
> > reconfigure and find another path.
>
> Which is what would happen anyway with your IGP if the service were
> delivered in the Access, but with fewer moving parts and less
> inter-dependence if the problem went beyond just ring failure or device
> crash.
>

Is the claim about fewer moving parts actually true? Yes if you are
comparing to a plain native single-stack network with IPv4 (or IPv6)
directly on the wire. But we are doing MPLS, so in our case it is L2VPN vs
L3VPN. Both will reroute using the exact same mechanism, so no difference
here.

I found that I could remove large parts of the configuration on the access
edge devices when we went from L3VPN to L2VPN. Some people will find the
network easier to understand when all major configuration is in only two
devices, and those two devices are mostly a mirror of each other.

I agree that L3VPN is the better solution, at least in principle. That is
why we started by implementing L3VPN. But in practice the L2VPN solution we
have now is actually easier.

Regards,

Baldur