[NANOG] RFC1918 conformance

Alex P. Rudnev alex at Relcom.EU.net
Wed Feb 12 10:58:30 UTC 1997

> >For example. I have a lot of CISCO routers with OSPF protocol. Thnis 
> >crazy IOS use highest loopback interface address as router-ID address; I 
> >use loopbacks to install load balancing etc. and I can't prevent 
> >loopbacks from being equal on the different routers. That's why I hardly 
> >need some IP addresses for 'Loopback 98' interface to use it as 
> >router-ID; and this have to be higher than any user's addresses. I use 
> > for this purposes, but it's not reserved address.
> >
> >This is one, simple, example why it's nessesary to reserve some short 
> >address space in the begin and in the end of total addresses.
> No, that's an example of a poorly designed protocol
> implementation. One ought to be able to specify an arbitrary router id
> for OSPF (heh - even Bay routers can do that :) rather that relying on
> such an odd algorithm. I was so surprised by this that I just had to go
> look it up:
I know _it's example of poorly designet software_. But I'd like to note 
it's not only example when it's usefull to have some addresses _greater 
than any other_ for private usage.

> <http://www.cisco.com/univercd/data/doc/software/11_2/cnp1/5ciprout.htm#REF38888>
> The equivalent Bay reference:
> <http://support.baynetworks.com/Library/tpubs/content/114065A/J_55.HTM#HEADING55-6>
Yes, I was more surprised when they (cisco) did not implement something 
like _ip ospf router-id A.B.C.D_ into new IOS 11.2. We have 3 or 4 
routing troubles due to this IOS property (and it always looked as 
_hidden bug_ because it is si,ular to the delayed bomb - it explodes 1 
week below some mistake was made in the config files -:)).

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