# <3 Comcast and IPv6



## KuJoe (Feb 7, 2014)

So I recently upgraded my home connection from 25Mbps to 50Mbps (I wanted cable and it was cheaper to get their bundle than to order the cable separate) and I was running some speed tests and noticed that Comcast's test site (http://speedtest.comcast.net) does both IPv4 and IPv6 tests. I noticed my IPv6 speed was almost 3 times faster than my IPv4 speeds and decided to run some tests using SD's test IPs/files.

Well during these tests I noticed that IPv6 takes half of the hops that IPv4 takes to the same server regardless of location. I also noticed that IPv6 is handed off to Level3 almost immediately which accounts for a 50ms decrease on average.

I'm pretty excited because I have IPv6 on every server/VPS that I use and even my servers on the east coast respond like they're local servers. I never had a lot of interest in IPv6 in the past but now that I'm using it on a daily basis in a real world environment I find that learning IPv6 doesn't feel like a chore, it's genuinely more fun now (and this coming from somebody who avoids networking whenever possible). When I was in FL, I did use different IPv6 tunnels but it wasn't the same for me.

So who else has a home ISP that provides native IPv6? How has it changed your views/experiences?


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## Aldryic C'boas (Feb 7, 2014)

Heh, my local ISP likely won't touch v6 until there's absolutely no other choice.

Sidenote:  I saw the _<3 Comcast_ in the thread title, and expected your entire post to be in purple <_<


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## KuJoe (Feb 7, 2014)

What does purple denote?

_PS - I'm colorblind so I avoid using colors online at all costs to avoid giving normal people a headache.  __ _


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## notFound (Feb 7, 2014)

It's the sarcasm tag.


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## Aldryic C'boas (Feb 7, 2014)

Yup, sarcasm   Is a refreshing change to hear something positive about Comcast for a change, though.


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## KuJoe (Feb 7, 2014)

And I fixed the speed issue with the IPv4 so now both are the same speeds (surprisingly this was resolved over their live chat, it's awesome not having to wait on hold and having a copy of the complete interaction with the support people).

Although even with the same speeds the latency is still bad and the number of hops haven't changed.


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## D. Strout (Feb 7, 2014)

Having never had it, I am very curious how native IPv6 to the home works. Do you have a /64? Or just one NATed address? What model is your modem and router? Did you have to do any config, or was it all set up for you? Did you connection come with IPv6, or did you have to ask for it? Any details appreciated.


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## KuJoe (Feb 7, 2014)

D. Strout said:


> Having never had it, I am very curious how native IPv6 to the home works. Do you have a /64? Or just one NATed address? What model is your modem and router? Did you have to do any config, or was it all set up for you? Did you connection come with IPv6, or did you have to ask for it? Any details appreciated.


I have a /64 assigned to my modem, it came default with my service when I ordered it.

I use my own modem and router (DOCSIS 3.0 is required for IPv6) which are a Motorola Surfboard modem and a cheap Cisco (Linksys) router (DD-WRT doesn't support IPv6 without some hacks that rarely work so I had to go buy a "normal" router from Best Buy).

My router grabs an IPv6 address automatically from Comcast so no configuration required that. I use static IPs on my end devices so I need to manually configure each OS (haven't looked at DHCPv6/autoconfig/whatever it is).


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## raidz (Feb 7, 2014)

Just a heads up, if you have CC, the newest pfSense 2.1.1 snapshots support their native ipv6. weeee


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## SPINIKR-RO (Feb 7, 2014)

I have Comcast v6 but my router does not yet support DHCP-PD (ubiquity ERL)


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## VPSCorey (Feb 7, 2014)

I use an Apple Airport base station with Comcast and all my devices get their own /64's via autoconf.


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## TheLinuxBug (Feb 7, 2014)

One other thing of note is from my experience they do not employ the same QOS on ipv6 as they do for ipv4.  I have been able to sustain transfers of up to 100Mbit on my cable modem over ipv6 (while only 70Mbit over ipv4) because of this.  Now of course not all routing is created equal so it has to be something closely peered to them to really get a sustain transfer rate.

Cheers!


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## mojeda (Feb 7, 2014)

Not sure if they still do this but since this article is from June of 2013 but I did see a reddit post about it recently:

http://www.theverge.com/2013/6/12/4424936/comcast-consumer-wi-fi-routers-captive-xfinity-hotspots

Comcast using your home connection for public wifi access to comcast customers.


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## dano (Feb 7, 2014)

Wish my IPv6 link was better than my IPv4 with Centurylink - I am in Albuquerque, and it backhauls everything to LA over IPv6, but it seems that over IPv4 I go through Denver mostly, or sometimes other more direct routes. I stopped using the IPv6 on CL after about 6months, as I was kinda getting sick of the added latency I would see. Hopefully they fix that for this region at some point.


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## texteditor (Feb 7, 2014)

I guess this means you are on a residential connection, since last I knew IPv6 wasn't 'stable enough' or whatever to roll out to business customers


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## jarland (Feb 7, 2014)

When Comcast rolled out ipv6 here in houston they rolled out this nice packet loss to go along with it.


So....lucky


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## KuJoe (Feb 7, 2014)

mojeda said:


> Not sure if they still do this but since this article is from June of 2013 but I did see a reddit post about it recently:
> 
> http://www.theverge.com/2013/6/12/4424936/comcast-consumer-wi-fi-routers-captive-xfinity-hotspots
> 
> Comcast using your home connection for public wifi access to comcast customers.


That's why I love that Comcast doesn't require you to use their equipment. I own my own modem and routers so I have complete control over them.



jarland said:


> When Comcast rolled out ipv6 here in houston they rolled out this nice packet loss to go along with it.
> 
> 
> So....lucky


Ouch! I've heard a lot of horror stories about Comcast but my only complaint is their encrypted traffic throttling but hopefully with the speed increase the throttled speed is more usable.



texteditor said:


> I guess this means you are on a residential connection, since last I knew IPv6 wasn't 'stable enough' or whatever to roll out to business customers


Yeah I am, I tried getting their business service but they didn't support it in my apartment complex.


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## SPINIKR-RO (Feb 7, 2014)

KuJoe said:


> Yeah I am, I tried getting their business service but they didn't support it in my apartment complex.



Well, I called Comcast once reporting a very serious issue regarding connectivity issue. I was prepared with examples and graphs but of course no one I could get in immediate contact with even knew what a router was.

I narrowed it down and simplified to eventually a 'supervisor' that I was having trouble accessing my work email, etc.

I was then immediately threatened to be sued by Comcast because I was using my home connection for work purposes and I was not subscribed to a business class service.

On a tangent I basically told this person to * off.

But yeah, Comcast Business has never been 'available' to me. I did a study and noted that there is really no difference in the service, its more expensive for less, with the same restrictions and caps.


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## KuJoe (Feb 7, 2014)

I was looking at Comcast Business to avoid the bandwidth caps that they used to place on all residential plans, luckily they did away with the caps in Colorado before I got here.


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## texteditor (Feb 7, 2014)

SPINIKR-RO said:


> But yeah, Comcast Business has never been 'available' to me. I did a study and noted that there is really no difference in the service, its more expensive for less, with the same restrictions and caps.


milfy_mildly_ different restrictions, but no caps, which is why I finally convinced my fraternity to upgrade to business a few years ago (+ a faster line) after our third shut-off for blowing through the caps


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## SPINIKR-RO (Feb 7, 2014)

It may also be different in separate regions. I know that across the bridge from me (in another state) my collegue has a different expectation and restriction on caps, etc.

We looked into it and while using about the same level of bandwidth he was being charged about $100 difference.


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## KuJoe (Feb 7, 2014)

On their FAQ page it shows that different areas have different bandwidth policies so it might pertain to your location.


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## nunim (Feb 8, 2014)

I wish my ISP, or an ISP available in my area would roll out IPv6.... I used to have a decent HE.net tunnel setup but since I got their IPTV package I'm forced to use one extra shitty router that doesn't support tunneling.   Maybe in 10 years.   

I don't think AT&T is offering v6 yet so props to Comcast, for once.


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## KuJoe (Feb 8, 2014)

I just found this site, pretty cool info regarding their IPv6 deployment.

http://www.comcast6.net/


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## AMDbuilder (Feb 8, 2014)

I got a little tired of dealing with AT&T Uverse to keep my bill somewhat reasonable, coupled with comcast users in my area having their speeds doubled.  I could get a 50/10 connection for less than AT&T, plus the addition of IPv6 which was simply awesome.

The installer didn't do a very good job of placing the cables, so I have coax running all over (generally looking bad).  That being said my service has otherwise been very solid, and after upgrading my router (currently using Airport Extreme) I have been enjoying native IPv6 connectivity.

I've enjoyed seeing more sites using/supporting IPv6, and Comcast giving me the ability to use IPv6 has been awesome


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