Peering Exchange Configurations

Jake Khuon khuon at
Thu Apr 8 11:48:18 CDT 2010

On Thu, 2010-04-08 at 11:02 -0500, Brad Fleming wrote:

> 1) Is a private AS typically used for the exchange side of the session?

Not in a typical public internet exchange.  that said, there is no
reason why one could not build an exchange point that uses private ASNs.
One might do this for a specialised application of PPVPN peering
partners but that is beyond what you are asking.

> 2) Are RFC1918 IPs typically used for the p2p links into the exchange?

No.  Public IXPs will provide an address space for its participants to
use.  That said, once again, there might be some very specific
non-public applications of exchange points which may use RFC1918 address

> 3) Do peering exchanges typically remove their AS from the path  
> advertised to exchange participants?

I'm assuming you are talking about routes exchanged via a route-server.
Most moderm deployments of RSes do act transparently but in the past
there have been cases where some exchange point participants did want to
see the RS' ASN in the ASPATH.  Merit's old RSes had the capbility to
turn on or off transparency on a peer-by-peer basis.  I am not sure
about modern RS implementations.

>      3a) If no: Do participants typically preference exchange-learned  
> routes over other sources?

That is a matter of personal reference and religion.  But in my
experience at larger exchanges with bigger players, the RSes' routes are
considered secondary and less preferred.

> 4) Do exchanges typically support the following address families?
>        IPv4 Multicast
>        IPv6 Unicast
>        IPv6 Multicast

IPv4 multicast and IPv6 unicast seems standard in modern IXPs but I'm
not sure about IPv6 multicast.

> In exchanges where a route server is employed:
> 4) Do participants have a p2p link into a simple routing environment  
> then multi-hop to a route server?

Not in modern exchange points.  In some older ones this was the case but
I think that's largely historic.

> 5) I see that Bird, OpenBDGd, and Quagga are all options for route  
> server software. Does one of those packages stand out as the clear  
> current choice for production peering exchanges?

I wouldn't say clear but BIRD seems to be gaining ground on the other
two.  There were some talk given at the last NANOG meeting in the route-
servers track...

/*=================[ Jake Khuon <khuon at NEEBU.Net> ]=================+
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