The Routing Over Large Clouds Mailing List Archive by date

[Andy Malis <malis@maelstrom.timeplex.com>]

>> > > While contemplating my hotel room roof after the monday rolc
>> > > meeting I wondered about the apparent sentiment in the rolc meeting
>> > > the the rfc1577 to nhrp transition would involve three periods:
>> > >   - Hosts use LIS ARP Server
>> > >   - Hosts use LIS ARP Server
>> > >   - Hosts must/can choose between ARP Server or NHRP Server.
>> > >   - Hosts must/can choose between ARP Server or NHRP Server.
>> > >   - Hosts only have NHRP Server.
>> > In the middle step, hosts register with both for the benefit of
>> > rfc1577 only hosts on the LIS, but *should* query NHRP.  Once no one
>> > is querying the RFC1577 server on a LIS, it can go away.  If I
>> > understood what was proposed at the meeting.
>> I though I heard that the middle step requires hosts to register with
>> ATMARP, which will cross-feed oneway to the NHRP server (co-located). 
>> ATMARP, which will cross-feed oneway to the NHRP server (co-located). 
>> NHRP is then used for off-LIS queries.
>That sounds perfectly resonable.  Then in step 3, ATM ARP is still
>That sounds perfectly resonable.  Then in step 3, ATM ARP is still
>used for registry only and NHRP is used exclusively for queries?

Attempting to clear up the confusion ... here is how the transition will
Attempting to clear up the confusion ... here is how the transition will
work:

Step 1: Only ARP servers are used as per RFC 1577.
Step 1: Only ARP servers are used as per RFC 1577.

Step 2: NHRP is phased in:
     2a. Hosts continue to register with the ARP server (until
     2a. Hosts continue to register with the ARP server (until
         ARP servers go away, for the benefit of non-NHRP hosts).
         ARP servers go away, for the benefit of non-NHRP hosts).
         ARP servers will leak registrations to NHRP servers, so NHRP
         ARP servers will leak registrations to NHRP servers, so NHRP
         hosts don't have to register twice if they don't wish to
         (but then they must agree to certain defaults, such as the
         registration timeout period).  If NHRP hosts wish to set
         these values, then they must also register with the NHRP
         server.  Explicit registrations always take precedence over
         leaked registrations.
     2b. NHRP source hosts send all address resolution requests
         to the NHRP server (without regard to the "mask and match"
         operation).
     2c. NHRP source hosts may send ARP requests to their ARP
     2c. NHRP source hosts may send ARP requests to their ARP
         server if they get a NHRP NAK and the destination is in the
         server if they get a NHRP NAK and the destination is in the
         same LIS.

Step 3: NHRP servers completely replace ARP servers.  All hosts
Step 3: NHRP servers completely replace ARP servers.  All hosts
        are NHRP-capable.  ARP servers no longer exist.
        are NHRP-capable.  ARP servers no longer exist.

Andy
Andy

__________________________________________________________________________
Andrew G. Malis   malis@maelstrom.timeplex.com             +1 508 266-4522
Andrew G. Malis   malis@maelstrom.timeplex.com             +1 508 266-4522
Ascom Timeplex    289 Great Rd., Acton MA 01720 USA   FAX: +1 508 264-4999
Ascom Timeplex    289 Great Rd., Acton MA 01720 USA   FAX: +1 508 264-4999