1GE L3 aggregation

Thu Jun 23 08:32:54 UTC 2016

On 22 June 2016 at 22:04, David Charlebois <dcharlebois at gmail.com> wrote:

> In our case, we advertise a single /24 from our head office to 2 upstream
> providers. The routing is %100 for redundancy.
>

The full table is in many cases overrated. If both your transits are good
service providers, you do not gain much by trying to get even better
routing compared to what the single homed customers of each provider is
getting. And that is basically what you are trying by taking in full tables.

The only thing to be beware of is some so called Tier 1 providers that have
bad interconnectivity to other Tier 1 providers. For example, neither
Cogent nor HE will give you a full view of the IPv6 network because these
two guys are in a peering war, so they miss the routes from the other
network. Taking in full tables allows you to select the correct provider
for the (relatively few) trouble routes, but note that you will still have
a problem if one link is down. The fix is to use smaller regional transit
providers, with each provider having multiple transits of his own.

For a feed with default route you can use the most basic BGP speaking
switch. Those are available for 1k USD or less. The ZTE switches we use are
in that range with copper ports and no 10G. Or you can get a Mikrotik
RB2011 for $99.

Or you can keep the full feed and use a Linux/BSD server for routing with
BIRD og Quagga. At 1G speed a server is going to do the job trivially. If
you want to be advanced, get two servers, one for each transit. Redundancy
on the LAN side can be provided by VRRP.

Regards,

Baldur