IPv6 migration steps for mid-scale isp

Wed Sep 20 15:04:45 UTC 2017

> On Sep 17, 2017, at 5:14 AM, Ahad Aboss <ahad at swiftelnetworks.com> wrote:
> 
> Hi Fredrik,
> 
> Running two different IGPs for IPv4 and IPv6 is a recipe for disaster even
> if it’s a short-term goal.
> 
> Here are a few things to consider;
> 
> OSPF is good for small ISPs with small routing tables (10 to 15K routes).
> It will support more routes but configuration of your network becomes more
> complex hence an increase in human error (network engineers)

Another perfectly workable alternative is to divide your network up into OSPF
instances which each have an internal ASN and linking them together with BGP.

> EIGRP is more suitable for mid-size say 50K subscriber base but you are
> really stretching your luck if you go beyond the 50K subscriber base.

You also have the problem that EIGRP locks you into an all-Cisco network.

> EIGRP is more susceptible to flap when adding a new device with an MTU
> mis-match etc. You can google up some stories about EIGRP flap issues….
> 
> My recommendation is to use iBGP for both IPv4/IPv6, you can use OSPF or
> EIGRP for link layer connectivity and iBGP to carry the traffic.
> 
> I prefer OSPF over EIGRP because of its equal cost load balancing if you
> have multiple interfaces from PE devices to your core.
> 
> iBGP is scalable, you can introduce router reflectors to avoid full mesh
> peering between PE routers – and the sky if your limit!

I think in general most serious networks consider this a question of OSPF
vs. ISIS for IGP and BGP is the only choice for EGP.

I find it interesting that you don’t even mention ISIS in your discussion.

I don’t know of any substantial networks running EIGRP these days. I’m not
saying they don’t exist, but they are certainly rare exceptions.

Owen

> 
> 
> 
> Hope this helps
> 
> 
> 
> Thanks
> 
> Ahad
> 
> 
> 
> 
> 
> On Sat, Sep 16, 2017 at 6:09 PM, Fredrik Sallinen <
> fredrik.sallinen at gmail.com> wrote:
> 
>> Thank you all for your Ideas. AFAIK one of the main decisions for IPv6
>> transition and deployment is the choice of IPv6 IGP. I read somewhere
>> that its a good practice to use different IGP protocol for IPv6 and
>> IPv4. For example if IGP for IPv4 is IS-IS then use OSPFv3 for IPv6.
>> any comments on this?
>> Additionally I will appreciate it if you share your suggestions on
>> products and their performance? For example If I go for NAT64+DNS64 to
>> handle IPv4 traffic, What sort of carrier grade products are you
>> recommending and can you share your experience on their
>> performance/pitfalls? currently we have ~150Gbps of IPv4 traffic, so
>> we need a solution to
>> support such scale and future growth.
>> 
>> 
>> Regards,
>> 
>> On Thu, Sep 14, 2017 at 9:35 PM, Mikael Abrahamsson <swmike at swm.pp.se>
>> wrote:
>>> On Wed, 13 Sep 2017, Fredrik Sallinen wrote:
>>> 
>>>> Hello,
>>>> 
>>>> Recently we have decided to start IPv6 migration in our network. We
>>>> have ~1K BNGs and connecting our customers to network using PPPoE.
>>>> I'd be interested in hearing from the technical community about their
>>>> experiences and recommendations on this process. I'm wondering:
>>>> 
>>>> Shall I go for IPv6-only deployment or dual stack?
>>> 
>>> 
>>> For PPPoE with existing IPv4, go dual stack.
>>> 
>>>> Where to start with IPv6? (core, edge or ...)
>>> 
>>> 
>>> Core, peering, work outwards towards end users.
>>> 
>>>> What are the best practices for ISPs?
>>>> What are the costs and return on investment?
>>>> How to identify address CPE and legacy application issues?
>>> 
>>> 
>>> There is a lot written and presented about IPv6 deployment. People have
>> been
>>> doing this in volume since around 2010, and if you search for IPv6
>>> deployment experience you'll find lots of presentations.
>>> 
>>> Some I found that seem relevant:
>>> 
>>> https://www.nanog.org/meetings/nanog51/presentations/Monday/aronson-
>> pierantozzi-level3-ipv6.pdf
>>> https://www.ietf.org/proceedings/54/slides/plenary-15.pdf
>>> https://www.apnic.net/community/ipv6-program/ipv6-stories/
>>> https://www.ipv6council.be/experiences-de-deploiements-ipv6/
>>> 
>>> If you prefer video form, there are lots of presentations from
>> conferences,
>>> available on youtube as well.
>>> 
>>> --
>>> Mikael Abrahamsson    email: swmike at swm.pp.se
>> 