Subject: [nemo] Q about NEMO Basic Support Protocol / Routing protocol-Implicit-Explicit??

From: "Seyed Hani Mohajerani" <[email-masked]>
Date: Fri, 15 Dec 2006 14:35:15 +1100

Hi, guys 

I am new in this mailing list & NEMO. 

I have few questions about NEMO Basic Support Protocol (RFC 3963), section:
5.2 Sending Binding Updates [page 10].

It says:

"A Mobile Router sends Binding Updates to its Home Agent, as described
   in [1].  If the Mobile Router is not running a routing protocol as
   described in section 8, it uses one of the following modes to tell
   the Home Agent to determine which prefixes belong to the Mobile
   Router.  In both modes, the Mobile Router sets the Mobile Router Flag
   (R).
 
      Implicit: In this mode, the Mobile Router does not include a Mobile
         Network Prefix Option in the Binding Update.  The Home Agent
         can use any mechanism (not defined in this document) to
         determine the Mobile Network Prefix(es) owned by the Mobile
         Router and to set up forwarding for the Mobile Network.  One
         example would be manual configuration at the Home Agent mapping
         the Mobile Router's Home Address to the information required
         for setting up forwarding for the Mobile Network.
 
      Explicit:..
"

My questions are:  

Couldn't routing protocol be one of mechanisms for HA to determine the
mobile Network Prefix(es) owned by MR in Implicit mode ?

And don't we need to set MR Flag (R) (for at least establishing tunnel) when
we are using a dynamic routing protocol [RFC 3963, Section 8]?

I reviewed the RFC few times but somehow it looks like a conflict to me!!

I appreciate if any body can answer my questions.

TA

-Seyed 

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---

From: Sri Gundavelli <[email-masked]>
Date: Thu, 14 Dec 2006 19:54:27 -0800 (PST)

> mobile Network Prefix(es) owned by MR in Implicit mode ?

Yes. If you enable dynamic routing over the MR-HA tunnel.

> we are using a dynamic routing protocol [RFC 3963, Section 8]?

Since, the mobile is functioning as a mobile router, it needs
to set the "R" bit in the BU message. Else, the home agent
will not enable forwarding for any prefixes over the tunnel.

Sri

---

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 18 Dec 2006 21:23:34 +0100

Hi, thanks for reading the document...

> I have few questions about NEMO Basic Support Protocol (RFC 3963), 
> section: 5.2 Sending Binding Updates [page 10].
> 
> It says:
>> 
>> “A Mobile Router sends Binding Updates to its Home Agent, as 
>> described in [1].  If the Mobile Router is not running a routing 
>> protocol as described in section 8, it uses one of the following 
>> modes to tell the Home Agent to determine which prefixes belong to
>>  the Mobile Router.  In both modes, the Mobile Router sets the 
>> Mobile Router Flag (R).
>> 
>>  Network Prefix Option in the Binding Update.  The Home Agent can 
>> use any mechanism (not defined in this document) to determine the 
>> Mobile Network Prefix(es) owned by the Mobile Router and to set up 
>> forwarding for the Mobile Network.  One example would be manual 
>> configuration at the Home Agent mapping the Mobile Router's Home 
>> Address to the information required for setting up forwarding for 
>> the Mobile Network.

That is is typically a static route in the kernel routing table.

>> Explicit:….
>> 
>> “
>> 
> My questions are:
> 
> Couldn’t routing protocol be one of mechanisms for HA to determine 
> the mobile Network Prefix(es) owned by MR in Implicit mode ?

Well, yes.  What you mean by 'routing protocol be a mechanism...'?  Do
you want an OSPF message from MR to HA to let HA know what that MNP is?
  Or do you mean an OSPF configuration file on HA to list that MNP?

I think both would work as long as HA checks the MNP against its Prefix
Table for security.

If it's along these lines you're asking, then it's also true that the
Implicit mode was specifically put there such that unmodified OSPF would
continue to work even if NEMOv6 didn't have the prefix in BU, the
extended mode.

> And don’t we need to set MR Flag (R) (for at least establishing 
> tunnel) when we are using a dynamic routing protocol [RFC 3963, 
> Section 8]?

YEs, we do.  Is the rfc3963 contradicting this?  The minimal NEMOv6
implementation would just set that R bit.  Routes could be configured
statically or with OSPF.

> I reviewed the RFC few times but somehow it looks like a conflict to 

Sorry, I'm trying to identify the conflicting text.

Alex