|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |
From: "Barton F Bruce" <barton@gnaps.com> To: "Jim Wininger" <jbotctc@gmail.com>, <nanog@nanog.org> Date: Thu, 30 Jul 2009 00:22:27 -0400 X-GlobalNaps-MailScanner-From: barton@gnaps.com Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org ----- Original Message ----- From: "Jim Wininger" <jbotctc@gmail.com> To: <nanog@nanog.org> Sent: Wednesday, July 29, 2009 3:59 PM Subject: Subnet Size for BGP peers. > I have a question about the subnet size for BGP peers. Typically when we > > turn up a new BGP customer we turn them up on a /29 or a /30. That seems > to > > be the "norm". > We connect to many of our BGP peers with ethernet. It would be a simple So what is wrong with a /31? We use /30s but if you are short on IP space, look at using /31 rather than /30 links. Cuts your space usage in half. If I remember correctly, the BIG problem with using /31s when they first became "legal" was to decide if the customer still gets the higher numbered IP address (or you the lower one), or if you still get the ODD number. No kidding, it is a problem for some! Where you are on ethernet, use a seperate 802.1q vlan per customer and have your switch give the customer untagged packets. If you have downstreams in your COLO, and either free or as a paid service, offer to setup private vlans in your switch for any pair or group of customers that need to also connect to each other privately for whatever they are doing. In that latter case, they will be getting tagged packets but their routers or switches should have no problem dealing with them. We don't charge for physical crossconnects, so this has saved us having to do physical crossconnects between customers, and has saved customers router ports.
|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |