[j-nsp] Core network design for an ISP

[Mark Tinka]

On 27/Mar/16 13:06, Saku Ytti wrote:

> You just as well might have hit IPv6 bug which crashes iosd ending in
> completely opposite conclusion. I think it's anecdotal. I think math
> supports fewer protocols and states. With sufficient large sample
> rate, you're always going to lose with your design.

True.

I could also have hit the same issue if MPLS were natively encapsulating
IPv6, assuming the bug was exposed to both planes. When you're stuffed,
you're stuffed.

My point is that I want to always to be able to default to simplicity
first. For this specific case, disabling MPLS resolved the IPv4
forwarding problem, even though it broke MPLS services (a moot point
since signaling of [IPv4] LSP's failed anyway, with MPLS enabled).

I'm not sure what other failure vector or scenario could present itself
with a more complex design (even if it brought reduced network state and
control plane activity), but I'm willing to add a little more state in
the network if it means the end design is structurally simple, until it
has to get complex.

Mark.