Multihoming using OpenBSD

[Geoff White]

Greetz,

I have a situation where I need to provide a network that is multihomed
(two different providers) The macnines on this network are mostly behind
a Linux VLS cluster [sic]. I have two problems that maybe someone can
give me a pointer to.

1) BGP is the obvious tried and true solution but where do you get tiny
CIDR blocks these days, like a /28 or /27 will they even hand out /24s
and now a days, who manages this aspect of the address space?

2) If running BGP is not the preferred way because of the logistics of
such a small CIDR request what other options are there, I remember
reading of some DNS hack back in 1997.


Any ideas? (you can e-mail me off line if you think the answer is not
appropriate for the group)

[Xavier Beaudouin]

Post by Geoff White
Greetz,
I have a situation where I need to provide a network that is
multihomed (two different providers) The macnines on this network are
mostly behind a Linux VLS cluster [sic]. I have two problems that
maybe someone can give me a pointer to.
1) BGP is the obvious tried and true solution but where do you get
tiny CIDR blocks these days, like a /28 or /27 will they even hand out
/24s and now a days, who manages this aspect of the address space?
2) If running BGP is not the preferred way because of the logistics of
such a small CIDR request what other options are there, I remember
reading of some DNS hack back in 1997.

I suggest :

- either get a lest a CIDR /24 because most of border routers just
filter CIDR block with > 24 bit so your network will
mostly reachable only to a few parts of the internet. Also to get a
AS you need... a least a /24... :(
- use hardware systems that gives the right IP what ever ip is comming
from... solutions are in general proprietary ones (like foundry,
f5....)
- use RR dns entry and pray that all providers are always up...

Post by Geoff White
Any ideas? (you can e-mail me off line if you think the answer is not
appropriate for the group)

--
Xavier Beaudouin - Unix System Administrator & Projects Leader.
President of Kazar Organization : http://www.kazar.net/
Please visit http://caudium.net/, home of Caudium & Camas projects

[Henning Brauer]

Post by Geoff White
I have a situation where I need to provide a network that is multihomed
(two different providers) The macnines on this network are mostly behind
a Linux VLS cluster [sic]. I have two problems that maybe someone can
give me a pointer to.
1) BGP is the obvious tried and true solution but where do you get tiny
CIDR blocks these days, like a /28 or /27 will they even hand out /24s
and now a days, who manages this aspect of the address space?

you get a /24 from one of your providers and make sure both of them
accept your announcement for that. since your /24 is the more specific
router over the provider's PA block it will Just Work. this is a pretty
standard setup/