ip dhcp snooping statistics

[Arthur Kant]

We are a service provider with an extremely large layer2 for DHCP in some areas.  I just enabled dhcp snooping on this vlan with:

ip dhcp snooping vlan 8

no ip dhcp snooping information option

no ip dhcp snooping verify mac-address

ip dhcp snooping

DHCP still appears to be flowing correctly but I am curious about the statistics Im seeing:

Packets Forwarded                                     = 26739

Packets Dropped                                       = 35498

Packets Dropped From untrusted ports                  = 45

What is causing dropped packets?  I could understand if bad foo was dropped from the untrusted ports but Im not sure of the other.

thanks!

[Jeff Van Houten]

You do have some ports identified as trusted, correct?

Sent from Cisco Technical Support iPad App

[Rolf Fischer]

Have you tried the "detail" option of the "show ip dhcp snooping statistics" command?

Packets Dropped Because
 IDB not known                                       = 0
 Queue full                                          = 0
 Interface is in errdisabled                         = 0
 Rate limit exceeded                                 = 0
 Received on untrusted ports                         = 0
 Nonzero giaddr                                      = 0
 Source mac not equal to chaddr                      = 0
 No binding entry                                    = 0
 Insertion of opt82 fail                             = 0
 Unknown packet                                      = 0
 Interface Down                                      = 0
 Unknown output interface                            = 0
 Misdirected Packets                                 = 0
 Packets with Invalid Size                           = 0
 Packets with Invalid Option                         = 0

http://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_58_se/command/reference/cli2.html#wp11913684

Best Regards

Rolf