IT_SWITCH#sh run | i snooping
ip dhcp snooping vlan 1
ip dhcp snooping
TEST_SW#sh run | i snooping
ip dhcp snooping vlan 100
ip dhcp snooping
TEST_SW#
TEST_SW#
TEST_SW#sh run int g0/14
Building configuration...
Current configuration : 155 bytes
!
interface GigabitEthernet0/14
description TO ROUTER
switchport trunk native vlan 100
switchport mode trunk
switchport nonegotiate
no keepalive
TEST_SW#sh run int vl 1
Building configuration...
Current configuration : 48 bytes
!
interface Vlan1
no ip address
shutdown
end
end
TEST_TEST#sh run
Building configuration...
Current configuration : 1460 bytes
!
! Last configuration change at 14:42:27 UTC Thu Nov 2 2017
!
version 15.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname TEST_TEST
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
system mtu routing 1500
!
!
!
!
!
!
ip dhcp snooping vlan 1-4094 smartlog
no ip dhcp snooping information option
ip dhcp snooping
!
!
!
spanning-tree mode rapid-pvst
spanning-tree extend system-id
!
!
!
!
vlan internal allocation policy ascending
!
interface GigabitEthernet0/6
description HOST
switchport access vlan 100
switchport mode access
spanning-tree portfast edge
!
interface GigabitEthernet0/10
description UPLINK
switchport trunk allowed vlan 100
switchport trunk native vlan 100
switchport mode trunk
!
interface Vlan1
no ip address
shutdown
!
interface Vlan100
ip address 10.90.9.253 255.255.255.0
no ip route-cache
!
ip forward-protocol nd
ip http server
ip http secure-server
!
!
!
!
!
line con 0
line vty 5 15
!
!
end
TEST_TEST#sh ip dhcp snooping
Switch DHCP snooping is enabled
Switch DHCP gleaning is disabled
DHCP snooping is configured on following VLANs:
1-4094
DHCP snooping is operational on following VLANs:
1,100
Smartlog is configured on following VLANs:
1-4094
Smartlog is operational on following VLANs:
1,100
DHCP snooping is configured on the following L3 Interfaces:
Insertion of option 82 is disabled
circuit-id default format: vlan-mod-port
remote-id: ec1d.8bac.2d00 (MAC)
Option 82 on untrusted port is not allowed
Verification of hwaddr field is enabled
Verification of giaddr field is enabled
DHCP snooping trust/rate is configured on the following Interfaces:
Interface Trusted Allow option Rate limit (pps)
----------------------- ------- ------------ ----------------
TEST_TEST#sh ip dhcp snooping statistics
Packets Forwarded = 27
Packets Dropped = 0
Packets Dropped From untrusted ports = 0
TEST_TEST#
Nov 2 15:36:41.468: %SYS-5-CONFIG_I: Configured from console by console
Nov 2 15:36:42.863: %LINK-3-UPDOWN: Interface GigabitEthernet0/6, changed state to down
Nov 2 15:36:45.400: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:45.400: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:36:45.404: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:45.404: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:36:45.404: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6,
TEST_TEST# MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:45.404: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:45.404: DHCP_SNOOPING: add relay information option.
Nov 2 15:36:45.404: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:36:45.404: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:36:45.404: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:36:45.404: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:36:45.404: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:36:45.425: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:45.425: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:36:45.425: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:45.425: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:36:45.425: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:45.425: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:45.425: DHCP_SNOOPING: add relay information option.
Nov 2 15:36:45.425: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:36:45.425: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:36:45.425: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:36:45.428: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:36:45.428: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:36:47.337: %LINK-3-UPDOWN: Interface GigabitEthernet0/6, changed state to up
Nov 2 15:36:48.340: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/6, changed state to up
Nov 2 15:36:48.497: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:48.497: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:36:48.497: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:48.497: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:36:48.497: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:48.497: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:48.497: DHCP_SNOOPING: add relay information option.
Nov 2 15:36:48.497: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:36:48.497: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:36:48.497: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:36:48.497: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:36:48.501: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:36:54.663: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:54.666: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:36:54.666: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:36:54.666: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:36:54.666: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:54.666: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:36:54.666: DHCP_SNOOPING: add relay information option.
Nov 2 15:36:54.666: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:36:54.666: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:36:54.666: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:36:54.666: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:36:54.666: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
TEST_TEST#
Nov 2 15:37:11.618: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:11.618: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:37:11.618: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:11.618: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:37:11.618: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6,u MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:11.618: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:11.618: DHCP_SNOOPING: add relay information option.
Nov 2 15:37:11.618: DHCP_SNOOPING_SW: encoding opt82 cin vlan-mod-port format
Nov 2 15:37:11.618: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:37:11.618: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:37:11.622: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:37:11.622: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:37:15.736: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:15.736: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:37:15.736: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:15.736: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:37:15.736: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:15.736: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:15.736: DHCP_SNOOPING: add relay information option.
Nov 2 15:37:15.736: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:37:15.736: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:37:15.736: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:37:15.739: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:37:15.739: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:37:22.845: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:22.845: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:37:22.845: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:37:22.845: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:37:22.849: DHCP_SNOOPING: process new DHCP packet, message type: DHCPREQUEST, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 0.0.0.0, DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:22.849: DHCP_SNOOPING: message type : DHCPREQUEST DHCP ciaddr: 0.0.0.0, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:37:22.849: DHCP_SNOOPING: add relay information option.
Nov 2 15:37:22.849: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:37:22.849: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:37:22.849: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:37:22.849: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:37:22.849: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:49:58.288: DHCP_SNOOPING_SW: bridge packet get invalid mat entry: FFFF.FFFF.FFFF, packet is flooded to ingress VLAN: (100)
Nov 2 15:49:58.288: DHCP_SNOOPING_SW: bridge packet send packet to cpu port: Vlan100.
Nov 2 15:50:03.276: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:50:03.276: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Vl100 for pak. Was Gi0/6
Nov 2 15:50:03.276: DHCPSNOOP(hlfm_set_if_input): Setting if_input to Gi0/6 for pak. Was Vl100
Nov 2 15:50:03.276: DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)
Nov 2 15:50:03.279: DHCP_SNOOPING: process new DHCP packet, message type: DHCPINFORM, input interface: Gi0/6, MAC da: ffff.ffff.ffff, MAC sa: 507b.9d72.dfc4, IP da: 255.255.255.255, IP sa: 10.90.9.52, DHCP ciaddr: 10.90.9.52, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:50:03.279: DHCP_SNOOPING: message type : DHCPINFORM DHCP ciaddr: 10.90.9.52, DHCP yiaddr: 0.0.0.0, DHCP siaddr: 0.0.0.0, DHCP giaddr: 0.0.0.0, DHCP chaddr: 507b.9d72.dfc4
Nov 2 15:50:03.279: DHCP_SNOOPING: add relay information option.
Nov 2 15:50:03.279: DHCP_SNOOPING_SW: encoding opt82 cid in vlan-mod-port format
Nov 2 15:50:03.279: DHCP_SNOOPING_SW: Encoding opt82 RID in MAC address format
Nov 2 15:50:03.279: DHCP_SNOOPING: binary dump of relay info option, length: 20 data:
Nov 2 15:50:03.279: 0x52
Nov 2 15:50:03.279: 0x12
DHCPInform
DHCPInform is a new DHCP message type, defined in RFC 2131, used by computers on the network to request and obtain information from a DHCP server for use in their local configuration. When this message type is used, the sender is already externally configured for its IP address on the network, which may or may not have been obtained using DHCP.
DHCP_SNOOPING: received new DHCP packet from input interface (GigabitEthernet0/6)Packet is received by interface Gi0/6.
DHCP_SNOOPING: process new DHCP packet, message type: DHCPINFORM,