[j-nsp] Core network design for an ISP

[Mark Tinka]

On 25/Mar/16 03:02, Luis Balbinot wrote:

> For iBGP consider multiple loopback addresses for different families. I'd
> do v4 and v6 (6PE with MPLS) with one family and inet-vpn, l2vpn, etc on
> another one. Even with newer REs a full table is taking quite some time to
> come up.

I'd rather native IPv6 than 6PE, just to remove IPv6 fate from IPv4.

We just had an issue where a router stopped forwarding IPv4 packets when
MPLS is enabled due to a software defect. Luckily, we could still log
into the box remotely over IPv6 is being run native.


>
> For IGP keep a flat area, no need to segment.
>
> If starting from scratch, look at BGP-LU. Running an MX core is expensive
> in terms of cost per port. You could run a much cheaper MPLS-only core in
> the future with 100Gbps interfaces at only a fraction of the cost of what a
> bunch of MPC4 cards would cost.

Wouldn't work if he had to run native IPv6 and whatever cheap core
router he is using does not have enough FIB slots to support the growing
IPv6 table. However, if he going to do 6PE (which I wouldn't), then this
is fine.


>
> For IXs I'd recommend a separate routing-instance. This will help you avoid
> stuff like someone defaulting to you and transit deviations.

Or a separate router, to keep things simple, if he can afford it.

Since the OP already has an outgoing MX80, he can dedicate that to
peering and not muck about with putting Internet traffic in VRF if he's
not so inclined.

Mark.