nanog mailing list archives
Re: BGP Homing Question
From: Patrick W Gilmore <patrick () ianai net>
Date: Sat, 28 Aug 2004 15:10:57 -0400
On Aug 28, 2004, at 12:02 AM, Michel Py wrote:
It is your netblock, you get to use it as needed.This is not a good reason; it might be a good excuse, but not a good reason.
Really? So if I have a /20, you are saying I cannot use it as I need to use it?
Also, filtering will not be an issue, if you are careful. Anyone who does not hear the /24 will hear the /20.Rick, you do need to tunnel the EU block from your US location back to your EU location, for people that are behind a filter that masks your /24. It does not happen often but it does happen. This leads to suboptimal asymmetric traffic, double whammy in terms of bandwidth (EU-bound traffic received by the US site from people that see the /20 and not the /24 that has to be re-sent back to EU over the tunnel) and interesting issues with stateful firewalls though.
You do not need to tunnel at all if your two upstreams trade downstream routes (e.g. "peer"), and the US upstream does not filter small prefixes from their peers.
As I said in the first post, this is much more common than the alternative, so chances are it will "just work".
-- TTFN, patrick
Current thread:
- Re: BGP Homing Question, (continued)
- Re: BGP Homing Question Joe Abley (Aug 27)
- Re: BGP Homing Question Patrick W Gilmore (Aug 27)
- Re: BGP Homing Question babylon (Aug 27)
- Re: BGP Homing Question Jared Mauch (Aug 27)
- Re: BGP Homing Question Randy Bush (Aug 30)
- Re: BGP Homing Question Joe Provo (Aug 30)
- Re: BGP Homing Question Daniel Roesen (Aug 30)
- Re: BGP Homing Question Patrick W Gilmore (Aug 27)
- Re: BGP Homing Question Joe Abley (Aug 27)
- Re: BGP Homing Question Patrick W Gilmore (Aug 28)