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IPv6 at home, prefix length and lease duration

Hi all,

Let's preface:

I'm in West Hollywood, when I started my plan it was TWC.

 

First question:

I fail to get anything else than a /64. Is this correct? Am I doing something wrong?

 

Second question:

How often does the prefix change? Every reboot? Every modem change? Every time Saturns goes around the sun? 

 

Thanks!

6 REPLIES 6
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Community Manager

Re: IPv6 at home, prefix length and lease duration

Welcome to the Community Forums!   

 

/64 is the default setting for IPv6.  Similar to a subnet mask in IPv4, it tells the system to divide the network into 64 subnetworks.  Lease durations are also configured in the modem settings, so it would depend on if that setting has been changed or not.  

 

I would suggest adding what you are trying to accomplish to your post in order to get input from your Forum peers.  

 

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Proven Sharer

Re: IPv6 at home, prefix length and lease duration

In your explanation, please lilst the make & model of the modem and your router.  Also discuss why you are not able to use a traditional IPv4 addressing scheme.  Keep in mind that with Spectrum internet service, you get only a single IPv4 public address.  The IPv6 is contained within your home LAN.

Re: IPv6 at home, prefix length and lease duration

Hitron E31N2V1 modem with Docsis 3.1.

My internet connection is 200/10.

 

When I request an IPv6 address I can only request a /64. I would like to know if this is correct. Most ISPs offer at least a /60 or a /56 for their customers.

 

@James_M unfortunately a /64 is not what is recommended per RFC 6177 https://tools.ietf.org/html/rfc6177 

 

@karlbeckman not true, you're prefectly able to request an IPv6 address.

 

I am trying out IPv6 for of learning IPv6.  

 

For that I need to know the longeavity of the prefix, as I need to hardcode this in many configurations. 

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Newcomer

Re: IPv6 at home, prefix length and lease duration

This is likely market dependent. Are you in an legacy Charter or legacy Time Warner Cable market?

 

I request a /64 for my home network, but request a /56 on larger (multi-VLAN) networks without an issue whether on Spectrum Business or Residential. I have a /56 subnet requested off of a Spectrum Business connection running behind an E31N2V1.

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Newcomer

Re: IPv6 at home, prefix length and lease duration

What you stated is incorrect.  By default, Spectrum will assign you a /64 network, which is the smallest SINGLE subnet that you can have.  An IPv6 address is 128 bits long.  The first 64 bits compose the network address portion, and the last 64 bitc compose the host addresss portion.  In other words, a /64 does not mean you are dividing the network into 64 subnets.

 

If your router ALLOWS IT, you can configure it to request a larger subnet, and apparently the only requested subnet size that Spectrum will accept is a /56.  If you receive this address block, it means that you can take that /56 network and create up to 256 /64 subnets.  Obviously, real overkill for any home/small business network, as each /64 network can address 1.84 E 19 hosts (which is more than today's entire public Internet can address).


@James_M wrote:

Welcome to the Community Forums!   

 

/64 is the default setting for IPv6.  Similar to a subnet mask in IPv4, it tells the system to divide the network into 64 subnetworks.  Lease durations are also configured in the modem settings, so it would depend on if that setting has been changed or not.  

 

I would suggest adding what you are trying to accomplish to your post in order to get input from your Forum peers.  

 


-rb

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Newcomer

Re: IPv6 at home, prefix length and lease duration


@from_the_future wrote:

Hi all,

Let's preface:

I'm in West Hollywood, when I started my plan it was TWC.

 

First question:

I fail to get anything else than a /64. Is this correct? Am I doing something wrong?

 

In order to obtain more than a /64 address block, you need to configure something called Prefix Delegation on your router (if it supports the feature).  And it looks like the only PD request they will honor is a /56.  Also, after you receive your prefix delegation, you should configure your router to request the same specific prefix again, so that your network hopefully won't change in the future.  It's similar to having a DHCP reservation.

 

Second question:

How often does the prefix change? Every reboot? Every modem change? Every time Saturns goes around the sun? 

 

The prefix appears to have a seven-day lease.  But if your router doesn't request the same prefix again, it may change when your router reboots.  It probably depends on the router you're using.

 

Thanks!