nanog mailing list archives
Re: Subnet Size for BGP peers.
From: Benjamin Billon <bbillon-ml () splio fr>
Date: Thu, 30 Jul 2009 00:09:27 +0200
Imagine two of your clients are competitors, they probably don't want to be on the same IP range. And yes, when you sell your service to several customers, you don't want one of them blowing up all the other's SLA.
IXs use /24, as far as I know, and peers connected there can usually use md5 password if they want to. But in that case, some troubles like arp broadcast storm could happen, coming from any of the connected network.
I guess it's not the same level of service, but I agree, many /30 or /29 are a big loss of addresses.
It reminds me GLBP with two gateways: on 10.0.0.0/29, you got 10.0.0.0 : network 10.0.0.7 : broadcast 10.0.0.1 : gw1 10.0.0.2 : gw2 10.0.0.6 : virtual gw only 3, 4 and 5 for other equipments. Who knows any other good way to lose IP addresses? Jim Wininger a écrit :
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 matter to allocate a /24 for connectivity to the customer on a shared link. This would help save on some address space. My question is, is this in general good or bad idea? Have others been down this path and found that it was a bad idea? I can see some of the pothols on this path (BGP session hijacking, incorrectly configured customer routers etc). These issues could be at least partially mitigated. Are there larger issues when doing something like this or is it a practical idea?
Current thread:
- Subnet Size for BGP peers. Jim Wininger (Jul 29)
- Re: Subnet Size for BGP peers. Nathan Ward (Jul 29)
- RE: Subnet Size for BGP peers. Paul Stewart (Jul 29)
- Re: Subnet Size for BGP peers. Benjamin Billon (Jul 29)
- Re: Subnet Size for BGP peers. Mikael Abrahamsson (Jul 29)
- Re: Subnet Size for BGP peers. Mikael Abrahamsson (Jul 30)
- Re: Subnet Size for BGP peers. Mikael Abrahamsson (Jul 29)
- Re: Subnet Size for BGP peers. Barton F Bruce (Jul 29)
- Re: Subnet Size for BGP peers. Doug McIntyre (Jul 30)
- Re: Subnet Size for BGP peers. Roy (Jul 30)
- Re: Subnet Size for BGP peers. Doug McIntyre (Jul 30)
- Re: Subnet Size for BGP peers. Adrian Minta (Jul 30)