IPv6 /56 subnet?

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Mort
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IPv6 /56 subnet?

Post by Mort » Thu Jun 27, 2019 11:29 am

Greetings,

I was looking through the settings options on my new NBN service and noticed an option in IPv6 to switch to a /56 subnet.

I'm curious what this option is for? Does it give me more than one IPv6 address or something to do with routing capabilities?

I only have a very basic understanding of things IPv6, but interested to know more.
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As we know, there are known knowns. There are things we know we know. We also know there are known unknowns. That is to say we know there are some things we do not know. But there are also unknown unknowns, the ones we don't know we don't know.

KavindaS
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Re: IPv6 /56 subnet?

Post by KavindaS » Thu Jun 27, 2019 5:34 pm

Mort wrote:
Thu Jun 27, 2019 11:29 am
Greetings,

I was looking through the settings options on my new NBN service and noticed an option in IPv6 to switch to a /56 subnet.

I'm curious what this option is for? Does it give me more than one IPv6 address or something to do with routing capabilities?

I only have a very basic understanding of things IPv6, but interested to know more.
With your current IPV6 /60 subnet, you have multiple usable IP addresses. By having /56 subnet, you can have even more usable IP addresses.

Mort
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Re: IPv6 /56 subnet?

Post by Mort » Thu Jun 27, 2019 7:26 pm

OK thanks, and these addresses are internet routable?
As we know, there are known knowns. There are things we know we know. We also know there are known unknowns. That is to say we know there are some things we do not know. But there are also unknown unknowns, the ones we don't know we don't know.

KavindaS
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Location: Sydney

Re: IPv6 /56 subnet?

Post by KavindaS » Thu Jun 27, 2019 8:27 pm

Mort wrote:
Thu Jun 27, 2019 7:26 pm
OK thanks, and these addresses are internet routable?
Yes.

phelum
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Re: IPv6 /56 subnet?

Post by phelum » Thu Jul 11, 2019 4:13 pm

Hi,

Am I correct in thinking that with a /60 subnet I would have 68 bits available for my device addresses ? 2 to the power of 68 is an awful lot of devices. Why would anybody need more addresses ? Or perhaps I don't understand IPv6 addressing.

Cheers,
-- Steven Saunderson

nilushid
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Re: IPv6 /56 subnet?

Post by nilushid » Thu Jul 11, 2019 9:46 pm

phelum wrote:
Thu Jul 11, 2019 4:13 pm
Hi,

Am I correct in thinking that with a /60 subnet I would have 68 bits available for my device addresses ? 2 to the power of 68 is an awful lot of devices. Why would anybody need more addresses ? Or perhaps I don't understand IPv6 addressing.

Cheers,
Hi

Yes, Technically there are 2 to the power of 68 IPV6 address. Having said that, in case if you are configuring sub networks, broadcast address and Subnet addresses cannot be assigned to nodes. All these address are dedicated to you, where as its not going to be duplicated. For more information please refer below web link.

https://computer.howstuffworks.com/inte ... ddress.htm

Thanks

phelum
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Re: IPv6 /56 subnet?

Post by phelum » Fri Jul 12, 2019 5:44 am

Hi,

Thanks for the info. What gets me is that if the prefix for all Exetel users is /48 (my assumption) and Exetel is offering each user a /60 subnet then there are only 12 bits left which limits the number of users to 4096. Whereas if Exetel only offered each user a /64 prefix then it could accommodate 65536 users.

Does Exetel have better than a /48 prefix ? I've seen 2406:3400:200:: and 2406:3400:219:: which implies a /40 prefix.

Just curious.

Cheers,
-- Steven Saunderson

rasikak
Exetel Staff
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Re: IPv6 /56 subnet?

Post by rasikak » Fri Jul 12, 2019 9:33 pm

phelum wrote:
Fri Jul 12, 2019 5:44 am
Hi,

Thanks for the info. What gets me is that if the prefix for all Exetel users is /48 (my assumption) and Exetel is offering each user a /60 subnet then there are only 12 bits left which limits the number of users to 4096. Whereas if Exetel only offered each user a /64 prefix then it could accommodate 65536 users.

Does Exetel have better than a /48 prefix ? I've seen 2406:3400:200:: and 2406:3400:219:: which implies a /40 prefix.

Just curious.

Cheers,
Thank you for reaching out. We have provided further details via an email to your nominated email address. #15615285

phelum
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Re: IPv6 /56 subnet?

Post by phelum » Sat Jul 13, 2019 5:13 am

rasikak wrote:
Fri Jul 12, 2019 9:33 pm
phelum wrote:
Fri Jul 12, 2019 5:44 am
Hi,

Thanks for the info. What gets me is that if the prefix for all Exetel users is /48 (my assumption) and Exetel is offering each user a /60 subnet then there are only 12 bits left which limits the number of users to 4096. Whereas if Exetel only offered each user a /64 prefix then it could accommodate 65536 users.

Does Exetel have better than a /48 prefix ? I've seen 2406:3400:200:: and 2406:3400:219:: which implies a /40 prefix.

Just curious.

Cheers,
Thank you for reaching out. We have provided further details via an email to your nominated email address. #15615285
Please let me rephrase my question. Has Exetel been allocated more than a /48 prefix ? E.g. /40 prefix ? I'm not requesting any addresses for myself; I'm just surprised about what seems a very generous allocation of addressing space for each user.

Cheers,
-- Steven Saunderson

KavindaS
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Re: IPv6 /56 subnet?

Post by KavindaS » Mon Jul 15, 2019 12:15 pm

phelum wrote:
Sat Jul 13, 2019 5:13 am

Thank you for reaching out. We have provided further details via an email to your nominated email address. #15615285
Please let me rephrase my question. Has Exetel been allocated more than a /48 prefix ? E.g. /40 prefix ? I'm not requesting any addresses for myself; I'm just surprised about what seems a very generous allocation of addressing space for each user.

Cheers,
[/quote]

Exetel does not provide a /48 IP block for users. We give a /60.

Since your first assumption is not correct, I hope you are clear about the rest of your query. We have a /32 IP block.

phelum
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Re: IPv6 /56 subnet?

Post by phelum » Mon Jul 15, 2019 12:39 pm

Yes, thanks for the info. After reading some APNIC documents I figured that maybe Exetel has a /32 block.

Cheers,
Steven
-- Steven Saunderson

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