Subject: (radius) Framed IP-Address Attibute (fwd)

From: MegaZone <[email-masked]>
Date: Tue, 8 Dec 1998 15:24:52 -0800 (PST)

Once upon a time ji choel park shaped the electrons to say...
>In  section 5.8 in rfc2138, there's description on Address field.
>
>"The value 0xFFFFFFFF indicattes that the NAS should allow the user to select an address (e.g. Negotiated).  The value 0xFFFFFE indicates that the NAS should select an address for the user (e.g. Assigned from a pool of addresses kept by the NAS).  Other valid values indicate that the NAS should use that value as the user's IP address"

0xFFFFFE is not valid - I presume you mean 0xFFFFFFFE

Yes:
'Framed-IP-Address = 255.255.255.255' means 'let the user pick any IP'
'Framed-IP-Address = 255.255.255.254' means 'assign the user an IP from your 
pool'

>If the value of the Address field is 0xFFFFFF, could the NAS allow the user to be assigned the address request by the user?  For example, the user is a Mobile Host of Mobile IP, and it requests its Home Address to the NAS.  If so, can the NAS assign the requested Home Address to the Mobile Node?

0xFFFFFF isn't valid - I presume you mean 0xFFFFFFFF?

When the NAS gets this the user can request, and should be allowed to use,
ANY IP address.  Hence this is a very dangerous thing to use - and in practice
is very rarely seen.

>Can the Frame-IP-Address Attribute be included in the Access-Accept packet, only when the previous Access-Request packet include the Attribute?  If not, what is the reason?

The Framed-IP-Address AVP can be included in ANY Access-Accept packet.  There
is no need to have received it in the Access-Request packet - and in fact
seeing it there is very rare in practice.

>As more basical question, why is the Framed-IP-Address Attribute needed in RADIUS?

1. Telling the NAS what to do.  By default most NASes will assign an IP from
their pool.  If you wish to allow the user to pick one you need to override
that behavior.
2. Static IP addresses for dialin users.  For example I have a static IP and
subnet routed to a continuous ISDN dialup line at home.  So my RADIUS entry
has the appropriate IP and netmask for this connection.
3. RADIUS IP pools.  Some RADIUS servers assign IP addresses from their own
pools, or using some formula such as NAS-IP-Address+NAS-Port.

-MZ
-- 
<URL:mailto:[email-masked]> Gweep, Discordian, Author, Engineer, me..
Join ISP/C Internet Service Providers' Consortium <URL:http://www.ispc.org/>
"A little nonsense now and then, is relished by the wisest men" 781-788-0130
<URL:http://www.megazone.org/>  <URL:http://www.gweep.net/>  Hail Discordia!
-
To unsubscribe, email [email-masked]' with
'unsubscribe ietf-radius' in the body of the message.