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General IPv6 Topics => IPv6 Basics & Questions & General Chatter => Topic started by: EganIPv6 on March 04, 2012, 12:58:09 PM

Title: IPv6 subnet
Post by: EganIPv6 on March 04, 2012, 12:58:09 PM
Hi -

I'm new to IPv6 and reading/learning as much as i can. I've successfully setup my tunnel and have IPv6 reachability. I'm confused about how to setup an all IPv6 environment. For example, If I were to a design a new small branch office that needed an external (internet), dmz, and internal subnets that had DHCPv6 pool for clients etc.

What should I be using for the firewall/router and switch ip addresses? Are they different than what the internal client addresses should be?

can someone point in the right direction or provide some guidance?

Thanks
Title: Re: IPv6 subnet
Post by: cholzhauer on March 04, 2012, 01:23:11 PM
did you already request your /48?  If not, you'll have to get that.  Next, select /64's from that to use on each subnet...each subnet gets its own /64.

So if your /48 was 2001:db8:1::/48 you could use 2001:db8:1:1::/64 for one network and 2001:db8:1:2::/64 for the other
Title: Re: IPv6 subnet
Post by: broquea on March 04, 2012, 04:31:29 PM
You do also get a routed /64 even before needing a /48...
Title: Re: IPv6 subnet
Post by: cholzhauer on March 04, 2012, 04:42:53 PM
Right but he was talking about multiple subnets at his remote office
Title: Re: IPv6 subnet
Post by: EganIPv6 on March 04, 2012, 06:07:53 PM
Yes, I did request and receive a /48. I went to http://www.subnetonline.com and carved out a few subnets. I even configured router-advertisements. My ipv6 clients can reach the internet but I not sure if the right direction to go or if I should be using DHCPv6.

What would a host entry look like for 2001:db8:1:1::/64?

I've come across a few IPv6 subnet calculators online but they don't seem to tell you how hosts per subnet etc, like traditional IPv4 subnets. Anyone seen anything like that?

I'm trying to think about how I design/configure IPv4 sites today and map that to IPv6.

Thanks for the help.
Title: Re: IPv6 subnet
Post by: cholzhauer on March 05, 2012, 05:21:58 AM
Really, it's about the same.

You can have something like 64 quintillion addresses per /64

As far as RA or DHCPv6, it's really up to you and what you're trying to accomplish.  The last I knew, even if you did DHCPv6, you'd still need to do RA so they hosts were able to set the default gateway.

As far as the addresses, again, it's up to you.  You can use the same connotations as you do with v4;  Use ::1 for the firewall address or ::254 for the switch

EDIT:

Quote

What would a host entry look like for 2001:db8:1:1::/64?

I'm not sure what you mean I guess....to have a valid address, you need to add something after the ::    2001:db8:1:1::1 would be a valid address
Title: Re: IPv6 subnet
Post by: EganIPv6 on March 05, 2012, 05:40:02 PM
Perfect. Thanks so much for helping out. I'm going to keep pushing along. My goal is to setup a v6 only site in order to learn specific aspects and configurations.
Title: Re: IPv6 subnet
Post by: kasperd on March 06, 2012, 11:06:22 PM
Quote from: cholzhauer on March 05, 2012, 05:21:58 AMThe last I knew, even if you did DHCPv6, you'd still need to do RA so they hosts were able to set the default gateway.
At some point in the past you would also need DHCPv6 even if you did RA, because the first version of RA did not tell hosts about DNS servers. The newest version of the standard does support DNS information over RA, but if you have a router or a client, which is too old, then you may need DHCPv6 to get DNS information to the clients.
Title: Re: IPv6 subnet
Post by: cholzhauer on March 07, 2012, 05:00:06 AM
Quote
At some point in the past you would also need DHCPv6 even if you did RA, because the first version of RA did not tell hosts about DNS servers. The newest version of the standard does support DNS information over RA, but if you have a router or a client, which is too old, then you may need DHCPv6 to get DNS information to the clients.

The dictionary defines this as "Cisco"  ;D