[149425] in North American Network Operators' Group
Re: IPv6 dual stacking and route tables
daemon@ATHENA.MIT.EDU (Ryan Rawdon)
Fri Feb 3 16:45:30 2012
From: Ryan Rawdon <ryan@u13.net>
In-Reply-To: <CABidiTLDRTAqqcbn1Qnmrr5RZGMJLVEg6c9aptu+Z98_6+XQdg@mail.gmail.com>
Date: Fri, 3 Feb 2012 16:44:33 -0500
To: tagno25@gmail.com
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Feb 3, 2012, at 3:25 PM, Philip Dorr wrote:
> You should accept the full v6 table, because some IPs may not,
> currently, be reachable via one of the carriers.
Definitely agreed here, and this is why we take full v6 tables. =
Especially since one of our upstreams does not peer with at least one =
other large network; if we took just a default from them, we would =
likely be sending them traffic which they in turn do not have a route =
for whereas the other upstream of ours does.
>=20
> On Fri, Feb 3, 2012 at 2:10 PM, -Hammer- <bhmccie@gmail.com> wrote:
>> So, we are preparing to add IPv6 to our multi-homed (separate routers =
and
>> carriers with IBGP) multi-site business. Starting off with a lab of =
course.
>> Circuits and hardware are a few months away. I'm doing the initial =
designs
>> and having some delivery questions with the carrier(s). One =
interesting
>> question came up. There was a thread I found (and have since lost) =
regarding
>> what routes to accept. Currently, in IPv4, we accept a default route =
only
>> from both carriers at both sites. Works fine. Optimal? No. =
Significantly
>> negative impact? No. In IPv6, I have heard some folks say that in a
>> multi-homed environment it is better to get the full IPv6 table fed =
into
>> both of your edge routers. Ok. Fine. Then, The thread I was referring =
to
>> said that it is also advisable to have the entire IPv4 table fed in
>> parallel. Ok. I understand we are talking about completely separate
>> protocols. So it's not a layer 3 issue. The reasoning was that DNS =
could
>> potentially introduce some latency.
>>=20
>> "If you have a specific route to a AAAA record but a less specific =
route to
>> an A record the potential is for the trip to take longer."
>>=20
>> That was the premise of the thread. I swear I googled it for 20 =
minutes to
>> link before giving up. Anyway, can anyone who's been thru this =
provide any
>> opinions on why or why not it is important to accept the full IPv6 =
table AND
>> the full IPv4 table? I have the hardware to handle it I'm just not =
sure long
>> term what the reasoning would be for or against. Again, I'm an end =
customer.
>> Not a carrier. So my concern is (A) my Internet facing applications =
and (B)
>> my users who eventually will surf IPv6.
>>=20
>> Any guidance would be appreciated. Thanks.
>>=20
>>=20
>>=20
>>=20
>> -Hammer-
>>=20
>> "I was a normal American nerd"
>> -Jack Herer
>>=20
>>=20
>>=20
>=20
