More ASN collissions

Rene Wilhelm wilhelm at
Thu Dec 10 20:42:52 CST 2009

Leo Bicknell wrote:
> In a message written on Thu, Dec 10, 2009 at 01:35:16PM -0500, Jared Mauch wrote:
>> As always, good research by renesys.
> [...]
> I would be very interested to know if something similar happened 
> with AS3745.
AS3745 is not a duplicate ASN assignment either. Like AS35868 the entry at is a user created object in the RIPE routing registry, not
an assignment by RIPE NCC.

The record in the ARIN database states:

OrgName:    Perot Systems
OrgID:      PEROTS-16
Address:    3800 Hamlin Road
City:       Auburn Hills
StateProv:  MI
PostalCode: 48326
Country:    US

ASNumber:   3745  
ASName:     VWAG-AS
ASHandle:   AS3745
RegDate:    1994-08-01
Updated:    2001-03-29

RTechHandle: AP105-ARIN
RTechName:   Accounts Payable, Mr. E. Zeltzer
RTechPhone:  +1-248-754-5803
RTechEmail:  domainmaster at

Both the ASName and RTechEmail already point to Volkswagen (VW). Querying for AP105-ARIN shows the full contact info:

Name:       Accounts Payable, Mr. E. Zeltzer
Handle:     AP105-ARIN
Company:    Volkswagen of America
Address:    Volkswagen of America
Address:    3800 Hamlin Road
City:       Auburn Hills
StateProv:  MI
PostalCode: 48326
Country:    US
RegDate:    1998-11-25
Updated:    2001-03-29
Phone:      +1-248-754-5803  (Office)
Email:      domainmaster at

So Perot Systems seems to have received this AS in 1994 for Volkswagen 

REX, RIPE NCC's prototype Resource EXplainer, shows AS3745 has been 
advertising and (both assigned to Volkswagen AG, 
as long as we have routing history from RIS. In 2001 and later years 
parts of
194.114/17 followed.


The RIPE DB lists AS3745 as "Volkswagen AG, Wolfsburg, Germany". 
Although not
consistent with the registration info in ARIN, you can at least see how, in
the 1990s, the German parent company started to use the assignment made 
to its
American subsidiary.

The odd one in the current set of prefixes advertised by AS3745 appears 
to be If you click on this prefix in the REX listing for AS3745
you see this announcement is in the routing tables since June 2008.
The encompassing 148.9/16 was originated by AS5089 from January 2003 to
January 2004 and by AS1294 for some short periods in 2000 and 2001.

A next click on the "Resource Holder" (near the top of the page) shows
the matching record in the ARIN database to be -
a direct assignment to Perot Systems, Plano, TX

Finally, a click on the "DNS and Reverse DNS" in REX removes any doubt 
the /18
is somehow related to Volkswagen: for November 2009 we found one reverse DNS
entry in the CAIDA IPv4 DNS-names dataset[*] pointing to a domain under .gov

In summary, AS3745 is indeed used by two different organizations, but 
it's the
users not the RIRs who created this situation.

-- Rene


More information about the NANOG mailing list