Well, the interesting part is that I checked the physical cabling and found no other or new unit had been attached to this switch which houses the proxy servers external interface, Internet Router, External Firewall interface, Sylvan Server external interface. Thats it. The room that houses the switch is locked with only IT personnel able to access it.
Very strange indeed, That is why I presented it to the group -----Original Message----- From: Tatsuya Kawasaki [mailto:[EMAIL PROTECTED]] Sent: Thursday, September 27, 2001 3:50 AM To: Charles Morin Subject: Re: Interesting MAC address causing IP conflicts Charles, first of all, in theory, as you might know MAC should be unique. But I have heard that it is possible that two devices may have the same MAC. This appeared to be the first "REAL" case I have ever heard. Well having said that, assume that info is correct. I still does not make sence. It appeard that this IP conflict happened due to the same MAC address. But remember in order to have such a thing, the both units must reside in the same local network. So here are some questions How the "outside" device is connected? Are they physically in the same building? If physically different site, are you running VPN or something btwn them? perharps someone is working the network? Tatsuya /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Tatsuya Kawasaki Allegiance Telecom Unlock the Power of the Internet http://www.kivex.com Phone 301.215.6777 Fax 301.215.5991 Affiliation given for identification not representation /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ On Wed, 26 Sep 2001, Charles Morin wrote: > > Yesterday in the late afternoon, we obtained notification, once at 3:30pm > that our proxy server had received an IP conflict and once at 6:14pm another > server on the "outside" link had received an IP conflict. The MAC addres was > the same for both of these "000102604865". This MAC address is registered > with the IEEE as > 000102 BBN (Bolt Beranek and Newman, Inc.) internal usage (not registered) > > I manually verified all connections to that switch and found no way for > anyone to have 'physically' plugged into it. > > Any ideas on who uses this mac address, and how this could have been > received on our outside link before the firewall??? > > > Thank You, > Charles Morin > Director Information Technology > New Horizons Computer Learning Centers > [EMAIL PROTECTED] > > > The sage does not accumulate (for himself). The more that he expends for > others, the more does he possess of his own; the more that he gives to > others, the more does he have himself > -Lao Tzu, Tao Te Ching > > > > This email and any files transmitted with it are confidential and are > intended solely for the use of the individual or entity to whom they are > addressed. This communication may contain material protected by the > attorney-client privilege. If you are not the intended recipient or the > person responsible for delivering the e-mail to the intended recipient, be > advised that you have received this e-mail in error and that any use, > dissemination, forwarding, bringing or copying of this email is strictly > prohibited. If you have received this e-mail in error; please immediately > notify New Horizons front desk by telephone at 1-805-496-9690. You will be > reimbursed for reasonable costs incurred in notifying us. > > _______________________________________________ > Firewalls mailing list > [EMAIL PROTECTED] > http://lists.gnac.net/mailman/listinfo/firewalls > This email and any files transmitted with it are confidential and are intended solely for the use of the individual or entity to whom they are addressed. This communication may contain material protected by the attorney-client privilege. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be advised that you have received this e-mail in error and that any use, dissemination, forwarding, bringing or copying of this email is strictly prohibited. If you have received this e-mail in error; please immediately notify New Horizons front desk by telephone at 1-805-496-9690. You will be reimbursed for reasonable costs incurred in notifying us. _______________________________________________ Firewalls mailing list [EMAIL PROTECTED] http://lists.gnac.net/mailman/listinfo/firewalls
