[Sis-csi] No call today

[Keith Hogie]

Will,

   You mentioned that you have been running this over Ethernet and are
not sure what happens with serial links.  What about the process for
generating link local addresses.

   I think the normal process for generating a link local address is to
use your MAC address in the last 64 bits.  This works great for Ethernet
but serial links don't have MAC addresses.  A MAC address is nice
because they are globally administered and unique.  What do we do to
avoid people randomly assigning their own serial link addresses and
ending up with one that matches someone else.

   Just one of those differences between the Ethernet multi-drop LAN
world and the serial point-to-point world.

Keith Hogie



Ivancic, William D. (GRC-RCN0) wrote:
> Keith,
>  
> I believe on can turn neighbor discovery off.  I believe many manets are
> interested in turning neighbor discovery off to reduce chatter and
> because one may not be connected to the manet or reachable during
> another's neighbor discovery process.  Space applications would be
> similar I suspect.
> 
> Yes, for any routing protocol, one needs bidirectional links.  Otherwise
> one has  to simply use static or default route.  These of course could
> be a weighted route such that if no other dynamic routes exist, send to
> the default.
>  
> Regarding the NEMO comment:
>  
>  
> 
>                 /------/                  /---.--/
>                     |                         |
>   2001:DB8:2:2::/64 |                         | 2001:DB8:3:3::1/64
>                     |                         |
>               +-----+----+              +-----'----+
>               | Router A |..............| Router B |
>               +----------+              +----------+
>   Example 1           10.1.2.1       10.1.2.2
>   Example 2        10.100.20.1       10.200.50.1
>   Example 3    2001:DB8:1:1::1       2001:DB8:1:2::1
> 
> 
> Example 1 is how IPv4 routing has to take place  (assume class C /24
> networks)
> 
> Example 2 will not allow for IPv4 routing (RIP/OSPF) as the interfaces
> are in different sub-networks.
> 
> Example 3 works for IPv6 because of link-local addressing.  We had three
> routers in series, not just the two shown.  Okey will be writing this up
> after the Holidays.  Everything so far has been over Ethernet.  I want
> to make sure the same goes for Serial.  I believe is should, but I
> always test my beliefs and have often been surprised.   
> 
> 
> 
> Will
> 
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   Keith Hogie                   e-mail: Keith.Hogie at gsfc.nasa.gov
   Computer Sciences Corp.       office: 301-794-2999  fax: 301-794-9480
   7700 Hubble Dr.
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