Run nbmac inside a logon script dumping machine name and mac address, or other identifying information.
On Tue, Mar 24, 2009 at 6:40 PM, Sam Cayze <[email protected]> wrote: > Thanks Ben! Good info (Especially since I don't know networking at this > level). > > >>Hire some local fifth graders to transcribe all the MAC address > stickers from each box for gumdrops or baseball cards or whatever kids > like these days. > > That's what someone did, and there are tons of errors. This is where I > come into fix it :) No stickers on the box; the devices had to be > opened, and the mac recorded off the physical chip on the card. I'm > looking for a more automated solution that leaves out human error & fat > fingering. > > > > > -----Original Message----- > From: Ben Scott [mailto:[email protected]] > Sent: Tuesday, March 24, 2009 5:21 PM > To: NT System Admin Issues > Subject: Re: Bulk Mac Address Inventory > > On Tue, Mar 24, 2009 at 5:18 PM, Sam Cayze <[email protected]> > wrote: > > Does the device that I am trying to capture the mac from need to have > > a valid IP on the same network? > > ARP is the mechanism the IP layer uses to learn the MAC address which > corresponds to an IP address. If you want to use ARP for MAC address > discovery, you need to know the particular IP address assigned to that > device. > > ARP works as follows. Say we have two computers on an Ethernet: > Alpha on 192.0.2.42, and Bravo on 192.0.2.31. Alpha has an IP datagram > to send to Bravo, but it only has Bravo's IP address. > Ethernet doesn't know anything about IP addresses; you need to give it a > destination MAC address. So Alpha sends a broadcast frame on the > Ethernet, asking "Who has 192.0.2.42?". Bravo sees the broadcast, and > sends a broadcast frame of its own, saying "192.0.2.42 is at <MAC > address>." Alpha sees that broadcast, and now knows what MAC address > to send Bravo's datagram to. Alpha puts this in its ARP table, so can > skip the ARP lookup for future datagrams to Bravo. > > When you say "arp -a" to Windows, you're asking Windows to tell you > the ARP addresses it has learned through the above process. (Plus any > static ARP entries, but that's not relevant to this.) > > > I think the devices are set to DHCP ... > > As someone else suggested, if DHCP is indeed enabled, your best bet is > to just connect each device one at a time, and get the MAC address from > the DHCP lease or logs. > > Keep in mind that many devices have multiple MAC addresses, and DHCP > will only report whatever MAC address the device used to request its > lease. If you need all of them, it's harder still. > > (I'm assuming you want to know which MAC address goes with which > device. If you just need to generate a list of MAC addresses which > corresponds to a pile of equipment, then you can power them all up at > once, plug them all into a switch, and just look at the DHCP logs when > you're done.) > > > Ideally, I would like to stick a cord in the device, have the mac > > populated via script, rinse and repeat for each machine... > > Other ideas: > > If the devices support SNMP and get IP addresses via DHCP, it should > be possible to use SNMP to get a list of all the MAC addresses > associated with a device. Assuming the devices implement the right MIB. > I'm don't know much about SNMP. > > Some devices implement a layer 2 discovery protocol. Cisco has CDP, > for example. More recently, there's a standard for LLDP (Link Layer > Discovery Protocol). These sorts of things can generally tell you the > MAC address of the connected port. > > Hire some local fifth graders to transcribe all the MAC address > stickers from each box for gumdrops or baseball cards or whatever kids > like these days. > > -- Ben > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ > <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ > ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
