[afnog] Do you aggregate?

[Mark Tinka]

On Thursday 06 August 2009 08:51:59 am Zartash Uzmi wrote:

> If so, do you aggregate manually or using some algorithm?

The process of route aggregation is not necessarily a 
complex one.

Normally, aggregation is as simple as announcing to the 
world, via BGP, the allocation handed to you by your RIR, 
exactly the way it was provided.

No special automation or algorithm is needed to do so.

> In either case (manual or automatic aggregation), how
> frequently do you aggregate? more frequent than the BGP
> updates frequency?
>
> If you aggregate, do you announce the aggregated prefixes
> or the original un-aggregated prefixes?

I could be wrong, but it is possible that you may have 
misunderstood the concepts of (BGP) routing and how they 
relate to the global Internet with regard to prefix 
announcement, prefix allocation and prefix (de)aggregation.

It's quite simple, really:

* One or more folk decide to start an ISP business.

* ISP requires IP addresses to provide services.

* ISP contacts its RIR for IP address & ASN resources.

* ISP announce its IP prefix(es) via BGP, aggregated.

* ISP chooses to de-aggregate for some reason, e.g., traffic
  engineering, e.t.c.

* ISP chooses to (re)aggregate for some reason, e.g., good
  netizenship, simplification of BGP routing policy, fewer
  number of upstreams/peers, fear of Philip Smith :-),
  e.t.c.

* Bottom two stages, above, may repeat at will.

The above will surely vary as no two networks are completely 
alike, but the point I'm trying to convey is that 
(de)aggregation is not a highly complex process that 
requires a decision on whether it be manual or automated.

It's merely a matter of policy designed by the IP engineers 
of a typical ISP, policy which is written down on paper and 
filed for documentation and reference, to be implemented via 
regular interface with IP routers.

> how big is your network? (Tier-1, 2, 3, campus, etc.)

This may be orthogonal to the subject at hand.

Cheers,

Mark.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 835 bytes
Desc: This is a digitally signed message part.
URL: <http://afnog.org/pipermail/afnog/attachments/20090810/5c47d718/attachment.bin>