It is for tracking purposes. There is more to it than just the giaddr of 0.0.0.0. If you look in the packet the option 82 information will also include the port the device came in on, the switchport.
If it was fully correct the giaddr would be an IP from one of the interfaces like VLAN1 but it doesn't thus the reason the relay agents complain. Regards, Tyson Scott - CCIE #13513 R&S, Security, and SP Managing Partner / Sr. Instructor - IPexpert, Inc. Mailto: [email protected] Telephone: +1.810.326.1444, ext. 208 Live Assistance, Please visit: www.ipexpert.com/chat eFax: +1.810.454.0130 IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, Audio Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S, Voice, Security & Service Provider) certification(s) with training locations throughout the United States, Europe, South Asia and Australia. Be sure to visit our online communities at www.ipexpert.com/communities and our public website at www.ipexpert.com <http://www.ipexpert.com/> From: [email protected] [mailto:[email protected]] On Behalf Of Kingsley Charles Sent: Wednesday, May 25, 2011 1:28 PM To: [email protected] Subject: [OSL | CCIE_Security] option 82 of GIAddr of 0.0.0.0 with dhcp snoopong Hi all When we enable dhcp snooping on the switch, why is option 82 of GIAddr of 0.0.0.0 added to the DHCP request packets flowing across? I don't see it added, when dhcp snooping is disabled. With regards Kings
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
