comments please

Howard C. Berkowitz hcb at
Tue Dec 8 21:12:58 UTC 1998

At 11:39 AM -0800 12/8/98, Bill Manning wrote:
>> On Tue, 8 Dec 1998, Bill Manning wrote:
>> >,, are the prefixes called out
>> > in RFC 1918. They are only for use in private networks that wish to use
>> > the IP protocols. Network operations and End System administrators should
>> > ensure that these prefixes is not coded into systems or routed through
>> > Internet infrastructure.  Since they have the appearance of "normal"
>> > special precautions should be taken to ensure that they are not
>> > in the Internet.
>> What about instances where an I/NSPs extends its use of these addresses to
>> the customer's boundary router?  This becomes epseically important if the
>> customer happens to have been doing its homework and using RFC1918
>> addresses only to find (after signing the contract) that they collide with
>> the provider's addresses.  Who wins in that case?
>> Mohamad Eljazzar
>> EET Data Communications
>Well, RFC 1918 says these prefixes should not be propogated over the Internet
>but can be used on/in Intranets.  I occasionally find it tough to discriminate
>between the two ideas.
And is it an intranet or an extranet when several ISPs use 1918 addresses
in their internal networks, such that the same address shows up several
times in the same traceroute, without a loop being present.  As Paul
Ferguson says of UDP, this is evil.


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