The Routing Over Large Clouds Mailing List Archive by date

[dhc2@gte.com]

Curtis,

Thanks for the comments.



<The application statement MUST document situations in which the
<protocol is NOT applicable.  You fail to do this.  There has been
<considerable discussion of route loops and conclusion that NHRP has no
<way to avoid them.  There is an application disclaimer in NHRP itself
<in section 8.1 (Router to Router operation).  This topic is also
<treated in the informational RFC-1620.

<A statement of the limitations belongs in the key features section.

I intented to do that in the Discussion section, but apparently
I was not sufficiently clear and explicit. I will do that in the
next version.

<> 5. Discussion
<> 
<>    NHRP is well suited for IP networks where hosts are routers are 
<>    interconnected via an NBMA network, especially if they are organized
<>    in terms of multiple LISs. In a Router-to-Router operation, under 
<>    certain conditions, a routing loop may occur. It is recommended that
<>    during Router-to-Router operation, options that help to detect loops
<>    be invoked and NHRP requests be reissued periodically. For the purpose
<>    loop prevention, it is advisable avoid the non-NBMA paths between
<>    the routers where NHRP is being run. If this option is not practical 
<>    and the loops persist, then NHRP is not well suited for such environments.
<
<The statement "For the purpose eeeg loop prevention, it is advisable
<avoid the non-NBMA paths between the routers where NHRP is being run."
<is total nonsense.  What you are stating is that if the Internet
<deploys an ATM network where multiple Internet service providers
<attach, those Internet service providers should never use routes
<learned from other media.  This is an unworkable attempt to whitewash
<the problem.

All I wrote was that if your application allows you to avoid
non-NBMA paths, then avoid it if you were to use NHRP between
the routers. Otherwise, do not use NHRP. I had no intention, 
nor any reason to whitewash the problem. 

<NHRP can only safely do address resolution.  You are trying to
<perpetuate the already disproven claim that NHRP is a viable
<replacement for routing.

Well, that was not my intention.

<Curtis

Derya