This behavior would occur if the traffic was routed to a loopback interface. -----Original Message----- From: Leo Bicknell [mailto:bicknell@ufp.org] Sent: Wednesday, September 19, 2001 8:09 AM To: nanog@merit.edu Subject: Re: looping traceroutes On Wed, Sep 19, 2001 at 12:40:51AM -0700, Ratul Mahajan wrote:
Do you think that it can be a real persistent routing loop (data packets would actually shuttle between the two interfaces) as against some wierdness because of traceroute?
I'd tell you a story, but it would make all of nanog cringe. Put simply, I know of at least one medium size regional network who when they couldn't make "bgp work" decided to implement a series of scripts that logged into all routers and installed statics to make things work. Let me just tell you, after a few short weeks of adding and removing (and missing) such routes there were loops all over the place, many of which are probably still there. :-( There are a number of ways long lived loops can occur. I believe others have pointed out some other methods. -- Leo Bicknell - bicknell@ufp.org Systems Engineer - Internetworking Engineer - CCIE 3440 Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org