nanog mailing list archives

Re: Starting a greenfield(ish) small (10k subs?) multihomed (two ASN) , dual stacked, wireless ISP - i can haz advice?


From: charles () thefnf org
Date: Fri, 25 Jul 2014 13:31:29 -0500



I highly recommend pfsense for a firewall (been using pfsense and
m0n0wall for years), but do have some concerns about using it at scale
for (several) thousands of users.

So far it's gone fairly well for the existing subscriber base. The current service footprint is ~1k homes. I think it's running on a Dell Poweredge ~29xxish , don't know for sure.

 Most of this relates to NAT/State
tracking, some of it hardware related, some of it software.

Right.

 If
possible, I would suggest you obtain a routable IP address per user
and avoid the pitfalls of NAT (I know at some point this may become
expensive).

Exactly.

If you start with IPv6 from day 1 you are in a lot better
place to encourage customers to upgrade to IPv6 capable gear.


Yes. We are doing v6 to every end user CPE. Absolutely. It will be there, be turned on and we hope to send all netflix/facebook/google etc traffic over v6. The v4 will be CGN. (We think we can only get a /24 reasonably).

@Comcast v6 team (and really anyone who has a large dualstack network (*waves* at Owen),

So you guys have v6 turned up. You passed 1tb of traffic. Didn't comcast also write some floss code for CGN? So presumably you'll have to start doing CGN soon.

Thoughts on long tail v4 only internet being seriously degraded by large scale CGN? (Maybe that's a new thread?) If the major properties are v6, shouldn't that be enough to keep the support costs down? (My friends in the MMORPG "cloud gaming" space tell me that my approach could wreak havoc with many game engines).

Thoughts on what happens when you've got v6 at your door and v4 at your CO? Who is running a network like this today (I imagine most small ISPs will be in that boat soon)?

(And also, what's up with people complaining about ARIN fees?). The air fiber radios FNF is installing in KC cost 5k capex. So enough already about a ONE TIME 1k fee and get your v6 space! (I agree with the posters who said if you can't afford the arin fee, GET OUT OF BUSINESS).


 I would
also suggest using stateless firewall rules and routing on your WAN
devices.

That does seem to be the common wisdom. I'm actually not 100% sure what we've got in line. It's OpenWRT based all around, so I'm sure IPTABLES (and maybe even some ebtables).


 This should simplify the functions performed by these boxes
to reduce the need to troubleshoot, apply updates, etc (resulting in
better availability).

Yeah. Of course.



 I haven't used pfsense in an ISP WAN router
capacity, and personally feel a router from Cisco, MikroTik, or
Ubiquiti's EdgeOS devices, etc may be more appropriate in this role.


I've got pretty much every Cisco router/switch in our lab, and an EdgeRouter.

What mikrotik should I evaluate?

Our lab : https://commons.thefnf.org/index.php/FNF_Lab


If you've automatically discounted big name gear due to upfront costs,
you might consider buying from a used equipment reseller (I can
recommend a few, if needed).

No. It's mostly for the customization/scripting etc. "SDN" and all that jazz. ;)



If you do need to use NAT, I feel like 500+ users sharing a single NAT
IP will result in poor quality of service and more admin overhead.

Quite possibly. However if it's just for long tail v4 only sites, I wonder how much it matters?


 My
gut feeling is that <50 may be more appropriate, depending on the
quality of service you want to provide. This provides some headroom if
one user makes many connections (p2p, virus infection, DoS attack) and
also lessens the number of subs you need to look at in cases of abuse
that are reported as an IP/port. Individual pfsense servers in a
cluster may provide scalable CGN services. I'm not sure how you want
to handle logging of all that data, but pfsense should allow you to
define rules that allow stateless auditing (ip 1.2.3.4, ports
1000-2000 always NAT to sub A). The XML config file or possibly the
shell is probably the easiest way to define such rulesets at scale.


Right right. I'm very familiar with the XML config and CLI. We've gotten to know pfSense well in our AutoTunnel (RADIUS) work. We patched (and released back to upstream) hostapd and other bits to actually correctly implement the RFC :D

So we've got a solution that is multi gateway. So based on the login creds you use, you get dropped into an appropriate vlan / BMX tunnel and get routed out the appropriate gateway.



I didn't see it mentioned, where (and to whom) are you multihoming?

Kansas City Kansas. Joesdatacenter.com is the current tower PoP. We can get transit from him, of course peer with KCIX , and we'll probably get transit from another local ISP in town (CTC). Of course level3/att/vz et al are all in town/on net and just a very short fiber hop away from Joes if we want to go that route.


 Do
you have a good working relationship with these folks (cell phone,
email contacts that reach someone promptly)?

Yes. Very much so.

Will you be considered a
facilities based ISP (and subject to CALEA or other regulation)?



I'm not sure. CALEA compliance is a very big deal for us. Especially in regards to making an open doc about being compliant and any necessary patches to the FLOSS supply chain for compliance.

As far as documentation goes, we're working on a FLOSS book:
https://commons.thefnf.org/index.php/Building_a_local_network_in_your_neighborhood

which will help folks build low cost community based access networks.

We are all about building a (business/technical/operational) model which can be readily and easily replicated by existing community based organizations and not need to wait on muni networks (with all of the complexity/risk/unknown unknowns etc that implies). The current bit about cities having to ASK the federal govt (mother may I build an ISP, even though the bullys have said I can't)? Are you kidding me? What happened to techies banding together, getting some management "bridge" types to organize the community and put up a network!


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