From: simon hart (simon.hart@btinternet.com)
Date: Wed May 04 2005 - 07:23:14 GMT-3
Frank,
What have you configured on the interface for the IPv6 address ?
If you configure an address that starts with FEC0::/10, then you have
configured a site local address. If you have configured an address that
starts with 2000::/3, then you have configured a global unicast address.
Think of it this way. If using IPv4 and I configure 158.1.50.4/24 on an
interface, then I have configured a globally routable address. If however I
have configured a 192.168.0.4/24 address I have configured a rfc1918 private
address that is not globally routable (will not route on the internet). You
should think of IPv6 site local addresses in the same way.
Now a Link Local address FE80::/10 will always be generated automatically by
either enabling IPv6 on an interface or by configuring a Global or Site
local address on the interface.
RFC 2373 will give a good overview on addressing.
Also check out the config guides on the DocCD
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/ipv6
_c/sa_bconn.htm
HTH
Simon
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Frank Center
Sent: 04 May 2005 03:02
To: simon hart; Jonathan ZD; my-ccie-test@libero.it;
ccielab@groupstudy.com
Subject: Re: IPv6 Addressing
This is what is confusing, when I look at the interface I see "link-local
address is FE80::20A:8AFF:FE83:1A40" but I thought that all site-local
addresses first 10 bits were FEC0?
----- Original Message -----
From: "simon hart" <simon.hart@btinternet.com>
To: "Frank Center" <ccahoon@maine.rr.com>; "Jonathan ZD"
<Nuvo25@hotmail.com>; <my-ccie-test@libero.it>; <ccielab@groupstudy.com>
Sent: Tuesday, May 03, 2005 3:36 PM
Subject: RE: IPv6 Addressing
> show ipv6 interface e0/0
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Frank Center
> Sent: 03 May 2005 19:04
> To: Jonathan ZD; my-ccie-test@libero.it; ccielab@groupstudy.com
> Subject: Re: IPv6 Addressing
>
>
> Is there a show command to view the site-local address?
>
> ----- Original Message -----
> From: "Jonathan ZD" <Nuvo25@hotmail.com>
> To: <my-ccie-test@libero.it>; <ccielab@groupstudy.com>
> Sent: Saturday, January 29, 2005 12:55 PM
> Subject: Re: IPv6 Addressing
>
>
> > The Address Structure for "Site-Local Unicast Address" is :
> >
> > 1st 10-bit : Site-Local unicast address identification (1111 1110 11 =
> FEC0)
> > 2nd 38-bit : All Zero
> > 3nd 16-bit (another word - last 16-bit of the 1st 64-bit of the address)
:
> > SLA (Site-Level Aggregator)
> > Last 64-bit: Inteface-ID (Auto Generated by converting interface
physical
> > address (mac-address) into EUI-64 format)
> >
> > Therefore, for the requirement, the address should be in the form of:
> >
> > FEC0: :A:X:X:X:X
> >
> > Where X:X:X:X: part is the auto-generated interface-id.
> >
> > *** The Address Structure - Refer to the section "3.1 Aggregatable
Global
> > Unicast Address Structure" from RFC 2374
> > *** The SLA (Site-Level Aggregator) - Refer to the section "3.5
Site-Level
> > Aggregation Identifier" from RFC 2374
> >
> > The answer from your work book kinda confuse me too.
> >
> > 1) I don't know that they mean by "site-local subnet 7B", and why that
> > address (7B) appear in the last 16 octect of the Interface-id??? For me,
> > site-local subnet should be part of SLA.
> >
> > 2) For Site-Local address, I believe that we (users) can only manipulate
> the
> > SLA part of the address, the last 64-bit of the address (interface-id)
> > should be generated by the router, so I don't understand how DOiT put
"7B"
> > under interface-id part of the address.
> >
> > 3) What they mean by "X" under the address???
> >
> > ----- Original Message -----
> > From: <my-ccie-test@libero.it>
> > To: <ccielab@groupstudy.com>
> > Sent: Saturday, January 29, 2005 7:12 AM
> > Subject: IPv6 Addressing
> >
> >
> > > Hi guys,
> > > I'm just started to study for my ccie lab test.
> > > I'm studing on Netmasterclass DOiT.
> > > it says in IPV6 topic:
> > >
> > > configure site-local subnet 7B on R1,R2,R3. Use SLA number A for this
> part
> > of the network.
> > > DOiT says the address is FEC0:0:0:A::7B:"x"/125
> > > I'm confused about subnet-id and SLA number.
> > >
> > > I read on RFC 3513:
> > >
> > > Site-Local addresses have the following format:
> > >
> > > | 10 |
> > > | bits | 54 bits | 64 bits |
> > > +----------+-------------------------+----------------------------+
> > > |1111111011| subnet ID | interface ID |
> > > +----------+-------------------------+----------------------------+
> > >
> > > Site-local addresses are designed to be used for addressing inside
of
> > > a site without the need for a global prefix. Although a subnet ID
> > > may be up to 54-bits long, it is expected that globally-connected
> > > sites will use the same subnet IDs for site-local and global
> > > prefixes.
> > >
> > > Routers must not forward any packets with site-local source or
> > > destination addresses outside of the site.
> > >
> > >
> > > It shows only subnet-id
> > > So, wath is SLA number?
> > > Why it doesn't show "7B" in the subnet-id field?
> > >
> > >
> > > thanks
> > >
> > >
This archive was generated by hypermail 2.1.4 : Fri Jun 03 2005 - 10:11:56 GMT-3