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mackey
Premium
join:2007-08-20
kudos:12
reply to NetDog

Re: [IPv6] Comcast IPv6 Address Assignment/Delegation

said by NetDog:

Does your CentOS Box have more then one VLAN or LAN behind the WAN? If not there is no point in asking for anything less then /64? Do you really need that may networks that a /60 will give you? Just asking...

I thought this thread was about the current state of getting something larger then a /64 on Comcasts' network, not justifying the need for something larger. My bad.

RFC 6177 says ISPs should issue something significantly larger then a /64 and "the default assignment size should take into consideration the likelihood that an end site will have need for multiple subnets in the future and avoid the IPv4 practice of having frequent and continual justification for obtaining small amounts of additional space."

I need more then a single /64. I shouldn't need to justify requesting something as tiny as a /60. Back on page 1 jjmb See Profile said the default size later this year will be a /60. Why are you guys even thinking about doing that if you feel no one has a valid reason for getting anything larger then a /64?

/M


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage
said by mackey:

I need more then a single /64. I shouldn't need to justify requesting something as tiny as a /60. Back on page 1 jjmb See Profile said the default size later this year will be a /60. Why are you guys even thinking about doing that if you feel no one has a valid reason for getting anything larger then a /64?

It's called the left hand vs right hand syndrome. It is a common malady in many (if not most) large organizations.
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


NetDog
Premium,VIP
join:2002-03-04
Parker, CO
kudos:79
reply to mackey
This is me just asking a question, trying to understand what people are thinking. Yes I have read that RFC, and a lot of others on IPv6 as well. I was thinking we could have a dialogue about this subject but I guess not.

So I will leave topic with this "Comcast will change the default to a /60 at a later date, but today it is /64. If your device supports requesting a smaller prefix up till a /60 you can request it."


Mike Wolf

join:2009-05-24
Beachwood, NJ
kudos:4
How do I know if my Linksys router supports these different things? Is there a way for Comcast to check?

biomesh
Premium
join:2006-07-08
Tomball, TX
reply to NetDog
My guess is that users will setup guest vlans or networks. This could also be used for vpn configurations in order to isolate their 'business network' from their 'home network'.

AVonGauss
Premium
join:2007-11-01
Boynton Beach, FL
reply to mackey
said by mackey:

RFC 6177 says ISPs should issue something significantly larger then a /64 and "the default assignment size should take into consideration the likelihood that an end site will have need for multiple subnets in the future and avoid the IPv4 practice of having frequent and continual justification for obtaining small amounts of additional space."

I need more then a single /64. I shouldn't need to justify requesting something as tiny as a /60. Back on page 1 jjmb See Profile said the default size later this year will be a /60. Why are you guys even thinking about doing that if you feel no one has a valid reason for getting anything larger then a /64?

/M

A bit of an over reaction, no? It was simply a question asked, not a demand for justification on how or for what purpose are you planning on using it - a fair question. I'd be willing to bet if we really took a look at it, this would fall more under the "I want to tinker" category, which is alright, but lets not masquerade it as something which it is not.


NetDog
Premium,VIP
join:2002-03-04
Parker, CO
kudos:79

1 edit
reply to Mike Wolf
said by Mike Wolf:

How do I know if my Linksys router supports these different things? Is there a way for Comcast to check?

Ok back to a dialogue???

Tell you the truth I only know two routers that support the a smaller prefix hint. Cisco IOS and a Cisco RV042G, other then that I have not tried other devices. But if you request a smaller prefix the DHCP server will grant to your device but depending on the CMTS your on will depend on if your route will get injected. It is safe at this time to just stick with the /64.

I will post when it is safe to request a smaller prefix.


NetDog
Premium,VIP
join:2002-03-04
Parker, CO
kudos:79
reply to biomesh
said by biomesh:

My guess is that users will setup guest vlans or networks.

This is what I am doing as well..

said by biomesh:

This could also be used for vpn configurations in order to isolate their 'business network' from their 'home network'.

This is totally the type of innovation I was looking for in that comment.. I didn't even think about a VPN type VLAN back to the office..


mackey
Premium
join:2007-08-20
kudos:12
said by NetDog:

This is totally the type of innovation I was looking for in that comment..

No, the way you phrased it and stated the obvious ("If not there is no point in asking for anything less then /64") it was clearly a challenge while saying you didn't think there was any reason to request something larger then a /64.

Of course there are multiple VLANs attached to it; I wouldn't be requesting something larger then a /64 otherwise. All the PCs and tablets are on one, a "guest" network is another, there are 4 or 5 VoIP phones and an Asterisk box on yet another, a locked down network that's only used for cleaning viruses, and while it's not really used any more, yet another is set up that had a couple file servers/NAS boxes on it.

Yes I'm aware that's only 5, and yes I'm aware that a /60 can be broken into 16 subnets, but there's no reason to be stingy with v6 addresses like there is with v4's and I like having elbow room to handle whatever tomorrow throws at me. I prefer to configure stuff once and not look at it again for quite a long time

I considered the VPN angle, but for my needs there's no reason to have an internet routable address assigned to that interface.

/M

AVonGauss
Premium
join:2007-11-01
Boynton Beach, FL
While I'm glad Comcast is going to give out a /60, and I'm not trying to pick on you personally, but you're saying 295,147,905,179,352,825,856 IPv6 addresses just won't be enough for say 256 real / virtual devices in the home?


whfsdude
Premium
join:2003-04-05
Washington, DC
Reviews:
·Comcast

1 edit
said by AVonGauss:

While I'm glad Comcast is going to give out a /60, and I'm not trying to pick on you personally, but you're saying 295,147,905,179,352,825,856 IPv6 addresses just won't be enough for say 256 real / virtual devices in the home?

Each VLAN or routed segment should be a /64 for the foreseeable future (netstacks stink, even without SLAAC in use). Which is why some segment (edit: network-pun unintended) of Comcast's residential users will need a /60.

AVonGauss
Premium
join:2007-11-01
Boynton Beach, FL
Oh I'm sure we can come up with all sorts of nifty ways to use routable IPv6 segments, but from the home user perspective, I think most other than a truly isolated guest network are probably more a product of tinkering rather than a definable need. I think Comcast's approach of providing additional routable segments only to those that request and know how to with DHCP-PD to be a very good compromise. Its far more than I personally was expecting from any decently sized residential provider to offer.


mackey
Premium
join:2007-08-20
kudos:12
said by AVonGauss:

Its far more than I personally was expecting from any decently sized residential provider to offer.

On Uverse, AT&T offers a /60 for each IPv4 address you have.

/M

AVonGauss
Premium
join:2007-11-01
Boynton Beach, FL
said by mackey:

On Uverse, AT&T offers a /60 for each IPv4 address you have.

/M

I wasn't aware that U-verse was offering native IPv6 at this point, though admittedly I don't follow it as closely as I once did. If they are now offering it to residential U-verse subscribers that is good news indeed. We might just get this IPv6 migration thing done in under two decades after all.

34764170

join:2007-09-06
Etobicoke, ON
said by AVonGauss:

I wasn't aware that U-verse was offering native IPv6 at this point, though admittedly I don't follow it as closely as I once did. If they are now offering it to residential U-verse subscribers that is good news indeed. We might just get this IPv6 migration thing done in under two decades after all.

It isn't native yet. They're using 6RD.


Mike Wolf

join:2009-05-24
Beachwood, NJ
kudos:4
reply to NetDog
Not sure what you mean by "back to a dialogue"
Anyway if you guys wanna do some testing on the IPv6 stuff, your're welcome to use me as a test subject What would requesting a smaller prefix entail, what would I gain, and what would I lose?


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

1 edit
said by Mike Wolf:

What would requesting a smaller prefix entail, what would I gain, and what would I lose?

It would entail having a router that was capable of maintaining multiple VLANS/LAN subnets, and the ability to be configured to request a PD other than the standard /64 from Comcast.

What you might gain is the ability to have multiple /64 IPv6 networks behind your router (how you would use them is up to you).

What you might lose is your internet connection if your router somehow got a /60 from Comcast and didn't know how to handle it.
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


Mike Wolf

join:2009-05-24
Beachwood, NJ
kudos:4
The whole internet connection would be lost? You mean even the IPv4 internet?


graysonf
Premium,MVM
join:1999-07-16
Fort Lauderdale, FL
kudos:2
reply to NetFixer
Any suggestion for values to try on a router that supports multiple LAN interfaces?

IPv6 Prefix Delegation:

Site-Level Aggregator ID: ?
ISP Prefix Length: /?
Expand your moderator at work


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage
reply to graysonf

Re: [IPv6] Comcast IPv6 Address Assignment/Delegation

said by graysonf:

Any suggestion for values to try on a router that supports multiple LAN interfaces?

IPv6 Prefix Delegation:

Site-Level Aggregator ID: ?
ISP Prefix Length: /?

Sorry, but the only router I have that supported getting a /60 (for a while) was my D-Link DIR655, and I don't have access to the low level configuration in that router (my only choice in its html menu is to either enable/disable DHCP-PD).




When I was getting a /60 from Comcast the config above was also being used, and a secondary router behind the DIR655 was able to get its own /64 IPv6 subnet. I have no idea why I no longer get a /60 from Comcast.

The screen shot below shows what I would get from Comcast when the /60 was working:




The DIR655 would get an IPv6 Network assignment of 2601:5:c80:90::/60, and its LAN would get the IPv6 assignment 2601:5:c80:91::/64. Unfortunately I did not get a screen capture of the secondary router's assignment, but as I recall it was 2601:5:c80:92::/64.

Now that I only get a /64 assignment, I get the same 2601:5:c80:90::/64 for both the Network and LAN.




My secondary (guest network) router is now connected directly (well, actually through a switch), to the modem and it still gets its own /64 assignment (it's just not a subnet of the DIR655's former /60 network).

One interesting thing is that just before I stopped getting the /60 assignment, Comcast changed the Network PD IP address from 2601:5:c80:90::/60 to 2601:5:c80:b0::/60. The next change was to eliminate the /60 assignment (but I went back to the 2601:5:c80:90: subnet again).




I guess that the point of this TLDR reply is to point out that Comcast's IPv6 implementation for dynamic IP address customers is still in flux (and may possibly stay that way), so even if you get something to work today, don't count on it to be working the same way tomorrow. If/when Comcast finally gets IPv6 for static IP business class customers working, I may go back to paying for static IP addresses again.
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


mackey
Premium
join:2007-08-20
kudos:12
reply to graysonf
said by graysonf:

Site-Level Aggregator ID: ?

Whatever you want, but when added to the prefix length the number of bits in it must be less than or equal to 64. I.e. if your prefix length is /64 then this must be 0. If your prefix length is /60 then it must be between 0 and 15 inclusive (0-15 = a 4-bit number. 4 + 60 = 64). This number is added to your prefix to get the subnet for that interface.

said by graysonf:

ISP Prefix Length: /?

The size of the prefix you're requesting from the ISP. Eventually Comcast will support /60-/64 inclusive, but for now only /64 works reliably.

/M