[f-nsp] NetIron MLX-4 vs Juniper MX240

[Rolf Hanßen]

Hi,

for the size of the routing table it does not matter if you advertise 2x
/48 or 2x /51 ;)
I would say its even better to have 2x /48 because the risk is 8x lower
that you will need to have another network because you need to have more
IPs.

best regards
Rolf

> Hey, you nailed me on the head!
>
> I have a /48 from ARIN and tried to advertise a /51 in datacenter 1 and a
> /51 in datacenter 2.  Upstream, in massive quantity, rejected all
> advertisements < /48.
>
> Which, unfortunately, is a problem.  That means if I want to use my own
> address space in two datacenters, I have to go get another /48 for the
> other
> datacenter.  This will indeed grow the routing table, when I have no need
> for so much address space.
>
> Scott
>
> On Wed, May 12, 2010 at 4:31 AM, George B. <georgeb at gmail.com> wrote:
>
>> On Wed, May 12, 2010 at 12:50 AM, Rolf Hanßen <nsp at rhanssen.de> wrote:
>> > Hi,
>> >
>> > it looks to me you calculate with an amount of v6 routes similar to
>> the
>> > number of v4 routes today and I thinks that this won't happen.
>> > For example: RIPE has assigned 5x IPv4 PA networks to us during the
>> last
>> > 10 years but we only use one /32 v6 network. We furthermore had to
>> splitt
>> > up those v4 assignments because we have a split network with several
>> > independent locations not connected together. This increased the
>> number
>> of
>> > prefixes we announce very fast.
>> > So the amount of v6 prefixes created from us will be much lower and I
>> > think other providers may have similar spaces they use.
>> > Even if you enable v6 for all networks currently using v4 I think
>> total
>> > amount will keep below 100k routes.
>> >
>> > kind regards
>> > Rolf
>>
>> For people who can qualify for a /32, particularly those who grew late
>> in the game, yes, there will be considerable consolidation.  What I
>> was more concerned about was smaller end user networks who currently
>> have a multi-homed /20 or smaller allocation that will be getting a
>> /44 or smaller v6 allocation and will keep both the v4 and v6
>> addresses.
>>
>> There are a lot of multi-homed /24 nets out there that will become a
>> /24 v4 and a /48 v6 announcement. I suppose the vendors could help
>> things somewhat by not putting the entire 128 bits into hardware.
>> There is really no reason to have more than 64 bits for routing as the
>> last 64 bits are "supposed" to be host IPs ... but how many out there
>> are using /127 for point-to-points between routers?   You aren't
>> "supposed" to subnet anything smaller than a /64 but many do.
>>
>> One thing I have noticed is that some networks are apparently
>> filtering anything smaller than a /32 from PA space but allowing
>> smaller nets from PI space designed for that purpose (down to a /48, I
>> think).  Anyone trying to multi-home a /64 is going to have a hard go
>> of it, I think, but someone is bound to try!
>>
>> George
>>
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>