Análisis de una transacción DHCP
Fecha: 10 de septiembre del 2014 Clase: Exploration 4
Escenario
Este laboratorio analiza la secuencia de tráfico DHCP que menciona el capítulo 7 de Exploration 4.
También se representa una situación de conflicto de direcciónes IP y como lo resuelve el servidor,
en este caso, un router Cisco 1841.
De la currícula Exploration 4:
En la nueva versión de CCNA 2 R&S:
1.- Generando tráfico DHCP:
C:\Users\CIT>ipconfig /release
Configuración IP de Windows
Adaptador de Ethernet Conexión de área local:
Sufijo DNS específico para la conexión. . :
Puerta de enlace predeterminada . . . . . :
C:\Users\CIT>ipconfig /renew
Configuración IP de Windows
Adaptador de Ethernet Conexión de área local:
Sufijo DNS específico para la conexión. . :
Dirección IPv4. . . . . . . .
. . . . . . . . . . . . . . . : 192.168.2.100
Máscara de subred . . . . . . . . . . . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada . . . . . : 192.168.2.1
C:\Users\CIT>
2.- Análisis del tráfico involucrado:
Frame 1: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80), Dst: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2)
Internet Protocol Version 4, Src: 192.168.2.100 (192.168.2.100), Dst: 192.168.2.1 (192.168.2.1)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x1137b344
Seconds elapsed: 3
Bootp flags: 0x0000 (Unicast)
Client IP address: 192.168.2.100 (192.168.2.100)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Release (7)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.2.1 (192.168.2.1)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Option: (255) End
Option End: 255
Padding
Frame 2: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x21f285ab
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Discover (1)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Option: (50) Requested IP Address
Length: 4
Requested IP Address:
192.168.2.100 (192.168.2.100) (ver
mas abajo tema de la registry)
Option: (12) Host Name
Length: 5
Host Name: CIT03
Option: (60) Vendor class identifier
Length: 8
Vendor class identifier: MSFT 5.0
Option: (55) Parameter Request List
Length: 12
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (15) Domain Name
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
Parameter Request List Item: (31) Perform Router Discover
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (249) Private/Classless Static Route (Microsoft)
Parameter Request List Item: (43) Vendor-Specific Information
Option: (255) End
Option End: 255
Padding
Frame 3: 70 bytes on wire (560 bits), 70 bytes captured (560 bits) on interface 0
Ethernet II, Src: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2), Dst: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Internet Protocol Version 4, Src: 192.168.2.1 (192.168.2.1), Dst: 192.168.2.100 (192.168.2.100)
Internet Control Message Protocol
Type: 8 (Echo (ping) request)(verificación de IP ya utilizada)
Code: 0
Checksum: 0xf11b [correct]
Identifier (BE): 8 (0x0008)
Identifier (LE): 2048 (0x0800)
Sequence number (BE): 1 (0x0001)
Sequence number (LE): 256 (0x0100)
Data (28 bytes)
0000 00 00 00 00 0a 6e 46 64 ab cd ab cd ab cd ab cd .....nFd........
0010 ab cd ab cd ab cd ab cd ab cd ab cd ............
Frame 4: 70 bytes on wire (560 bits), 70 bytes captured (560 bits) on interface 0
Ethernet II, Src: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2), Dst: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Internet Protocol Version 4, Src: 192.168.2.1 (192.168.2.1), Dst: 192.168.2.100 (192.168.2.100)
Internet Control Message Protocol
Type: 8 (Echo (ping) request) (verificación de IP ya utilizada)
Code: 0
Checksum: 0xeb3e [correct]
Identifier (BE): 8 (0x0008)
Identifier (LE): 2048 (0x0800)
Sequence number (BE): 2 (0x0002)
Sequence number (LE): 512 (0x0200)
Data (28 bytes)
0000 00 00 00 00 0a 6e 4c 40 ab cd ab cd ab cd ab cd .....nL@........
0010 ab cd ab cd ab cd ab cd ab cd ab cd ............
Frame 5: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 192.168.2.1, Dst: 255.255.255.255(en ambas currículas aparece como
unicast)
User Datagram Protocol, Src Port: 67 (67), Dst Port: 68 (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x21f285ab
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 192.168.2.100 (192.168.2.100)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Offer (2) (en ambas currículas aparece como
unicast)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.2.1 (192.168.2.1)
Option: (51) IP Address Lease Time
Length: 4
IP Address Lease Time: (86400s) 1 day (opción por default)
Option: (58) Renewal Time Value
Length: 4
Renewal Time Value: (43200s) 12 hours (al 50% de tiempo de alquiler)
Option: (59) Rebinding Time Value
Length: 4
Rebinding Time Value: (75600s) 21 hours (nuevo intento si el anterior fracasa)
Option: (1) Subnet Mask
Length: 4
Subnet Mask: 255.255.255.0 (255.255.255.0)
Option: (3) Router
Length: 4
Router: 192.168.2.1 (192.168.2.1)
Option: (255) End
Option End: 255
Padding
Frame 6: 348 bytes on wire (2784 bits), 348 bytes captured (2784 bits) on interface 0
Ethernet II, Src: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80),
Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x21f285ab
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Request (3)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Option: (50) Requested IP Address
Length: 4
Requested
IP Address: 192.168.2.100 (192.168.2.100)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.2.1 (192.168.2.1)
Option: (12) Host Name
Length: 5
Host Name: CIT03
Option: (81) Client Fully Qualified Domain Name
Length: 8
Flags: 0x00
0000 .... = Reserved flags: 0x00
.... 0... = Server DDNS: Some server updates
.... .0.. = Encoding: ASCII encoding
.... ..0. = Server overrides: No override
.... ...0 = Server: Client
A-RR result: 0
PTR-RR result: 0
Client name: CIT03
Option: (60) Vendor class identifier
Length: 8
Vendor class identifier: MSFT 5.0
Option: (55) Parameter Request List
Length: 12
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (15) Domain Name
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
Parameter Request List Item: (31) Perform Router Discover
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (249) Private/Classless Static Route (Microsoft)
Parameter Request List Item: (43) Vendor-Specific Information
Option: (255) End
Option End: 255
Frame 7: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 192.168.2.1 (192.168.2.1), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 67 (67), Dst Port: 68 (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x21f285ab
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address:
192.168.2.100 (192.168.2.100)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: ACK (5)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.2.1 (192.168.2.1)
Option: (51) IP Address Lease Time
Length: 4
IP Address Lease Time: (86400s) 1 day
Option: (58) Renewal Time Value
Length: 4
Renewal Time Value: (43200s) 12 hours
Option: (59) Rebinding Time Value
Length: 4
Rebinding Time Value: (75600s) 21 hours
Option: (1) Subnet Mask
Length: 4
Subnet Mask: 255.255.255.0 (255.255.255.0)
Option: (3) Router
Length: 4
Router: 192.168.2.1 (192.168.2.1)
Option: (255) End
Option End: 255
Padding
Frame 8: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 192.168.2.100 (192.168.2.100), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0xcd27cf54
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 192.168.2.100 (192.168.2.100)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Inform (8) (informa a todos los posibles
servidores de DHCP de la red)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Option: (12) Host Name
Length: 5
Host Name: CIT03
Option: (60) Vendor class identifier
Length: 8
Vendor class identifier: MSFT 5.0
Option: (55) Parameter Request List
Length: 13
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (15) Domain Name
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
Parameter Request List Item: (31) Perform Router Discover
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (249) Private/Classless Static Route (Microsoft)
Parameter Request List Item: (43) Vendor-Specific Information
Parameter Request List Item: (252) Private/Proxy autodiscovery
Option: (255) End
Option End: 255
Padding
Frame 9: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Ethernet II, Src: 00:1f:9e:c2:7a:a2 (00:1f:9e:c2:7a:a2), Dst: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Internet Protocol Version 4, Src: 192.168.2.1 (192.168.2.1), Dst: 192.168.2.100 (192.168.2.100)
User Datagram Protocol, Src Port: 67 (67), Dst Port: 68 (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0xcd27cf54
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 192.168.2.100 (192.168.2.100)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 54:be:f7:57:f2:80 (54:be:f7:57:f2:80)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: ACK (5) (da acuse de recuse de recibo del
alquiler)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.2.1 (192.168.2.1)
Option: (1) Subnet Mask
Length: 4
Subnet Mask: 255.255.255.0 (255.255.255.0)
Option: (3) Router
Length: 4
Router: 192.168.2.1 (192.168.2.1)
Option: (255) End
Option End: 255
Padding
3.- Verificación en el router:
BsAs#sh ip dhcp bind
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
192.168.2.100
0154.bef7.57f2.80 Sep 11
2014 07:12 PM Automatic
BsAs#
Detalle:
The unique identification of the client is specified in dotted hexadecimal notation; for example, 0154.bef7.57f2.80,
where 01 represents the Ethernet media type. Fuente: http://www.cisco.com
BsAs#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.0.5 134 001d.46a5.2761 ARPA FastEthernet0/1
Internet 10.0.0.6 - 001f.9ec2.7aa3 ARPA FastEthernet0/1
Internet 192.168.2.1 - 001f.9ec2.7aa2 ARPA FastEthernet0/0
Internet 192.168.2.100 9 54be.f757.f280 ARPA FastEthernet0/0 (sin el 01 del show anterior)
BsAs#
4.- Pruebas con la IP 192.168.2.100 utilizada como IP fija y solapada
en el rango DHCP:
Se simula la situación donde se conecta a la red una PC con IP fija que se encuentra dentro
del rango de direcciones del pool DHCP, analizamos que sucede tras bambalinas.
En la PC con DHCP:
Las PCs con sistema operativo Windows solicitan una dirección DHCP, pero con preferencia
a la última IP utilizada, es información queda almacenada en la registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces\
Verificación de la preferencia de una IP (aún luego de realizado el
ipconfig /release):
Al realizar ipconfig /renew:
C:\Users\CIT>ipconfig /renew
Configuración IP de Windows
Error al renovar la interfaz Conexión de área local : El cliente DHCP ha obtenido una dirección IP
que ya está en uso en la red. La interfaz local será deshabilitada hasta que el cliente DHCP pueda
obtener una nueva dirección.
C:\Users\CIT>ipconfig
Configuración IP de Windows
Adaptador de Ethernet Conexión de área local:
Sufijo DNS específico para la conexión. . :
Dirección IPv4. . . . . . . .
. . . . . . . . . . . . . . .: 192.168.2.101
Máscara de subred . . . . . . . . . . . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada . . . . . : 192.168.2.1
C:\Users\CIT>ping 192.168.2.1 (verificamos conectividad)
Haciendo ping a 192.168.2.1 con 32 bytes de datos:
Respuesta desde 192.168.2.1: bytes=32 tiempo<1m TTL=255
Respuesta desde 192.168.2.1: bytes=32 tiempo<1m TTL=255
Respuesta desde 192.168.2.1: bytes=32 tiempo<1m TTL=255
Respuesta desde 192.168.2.1: bytes=32 tiempo<1m TTL=255
Estadísticas de ping para 192.168.2.1:
Paquetes: enviados = 4, recibidos = 4, perdidos = 0
(0% perdidos),
Tiempos aproximados de ida y vuelta en milisegundos:
Mínimo = 0ms, Máximo = 0ms, Media = 0ms
C:\Users\CIT>
En la PC con IP fija:
En el router:
BsAs#clear ip dhcp binding * (borramos todas los alquileres)
BsAs#sh ip dhcp bind
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
BsAs#
Sep 13 09:06:56.259: DHCPD: Sending notification of DISCOVER:
Sep 13 09:06:56.259: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:06:56.259: DHCPD: remote id 020a0000c0a8020100000000
Sep 13 09:06:56.259: DHCPD: circuit id 00000000
Sep 13 09:06:56.259: DHCPD: Seeing if there is an internally specified pool class:
Sep 13 09:06:56.259: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:06:56.259: DHCPD: remote id 020a0000c0a8020100000000
Sep 13 09:06:56.259: DHCPD: circuit id 00000000
Sep 13 09:06:58.259: DHCPD: client requests 192.168.2.100. (esto es porque queda en la registry de Windows la última IP utilizada)
Sep 13 09:06:58.259: DHCPD: Adding binding to radix tree
(192.168.2.100) (la IP que
está utilizada por una PC con IP fija)
Sep 13 09:06:58.259: DHCPD: Adding binding to hash tree
Sep 13 09:06:58.259: DHCPD: assigned IP address 192.168.2.100 to client 0154.bef7.57f2.80.
Sep 13 09:06:58.259: DHCPD: Sending notification of ASSIGNMENT:
Sep 13 09:06:58.259: DHCPD: address 192.168.2.100 mask 255.255.255.0
Sep 13 09:06:58.259: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:06:58.259: DHCPD: lease time remaining (secs) = 86400 (son 24 horas)
Sep 13 09:06:58.607: DHCPD: Sending notification of TERMINATION:
Sep 13 09:06:58.607: DHCPD: address 192.168.2.100 mask 255.255.255.0
Sep 13 09:06:58.607: DHCPD: reason flags: DECLINE
Sep 13 09:06:58.607: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:06:58.607: DHCPD: lease time remaining (secs) = 86400
Sep 13 09:06:58.607: DHCPD: returned 192.168.2.100 to address pool DHCP.
Sep 13 09:06:58.607: %DHCPD-4-DECLINE_CONFLICT: DHCP address conflict: client 0154.bef7.57f2.80 declined 192.168.2.100.
Sep 13 09:07:08.611: DHCPD: Sending notification of DISCOVER:
Sep 13 09:07:08.611: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:07:08.611: DHCPD: remote id 020a0000c0a8020100000000
Sep 13 09:07:08.611: DHCPD: circuit id 00000000
Sep 13 09:07:08.611: DHCPD: Seeing if there is an internally specified pool class:
Sep 13 09:07:08.611: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:07:08.611: DHCPD: remote id 020a0000c0a8020100000000
Sep 13 09:07:08.611: DHCPD: circuit id 00000000
Sep 13 09:07:10.611: DHCPD: Adding binding to radix tree (192.168.2.101)
Sep 13 09:07:10.611: DHCPD: Adding binding to hash tree
Sep 13 09:07:10.611: DHCPD: assigned IP address 192.168.2.101 to client 0154.bef7.57f2.80.
Sep 13 09:07:10.611: DHCPD: Sending notification of ASSIGNMENT:
Sep 13 09:07:10.611: DHCPD: address 192.168.2.101 mask 255.255.255.0
Sep 13 09:07:10.611: DHCPD: htype 1 chaddr 54be.f757.f280
Sep 13 09:07:10.611: DHCPD: lease time remaining (secs) = 86400
BsAs#sh ip dhcp bind
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
192.168.2.101 0154.bef7.57f2.80 Sep 14 2014 09:07 AM Automatic
BsAs#
5.- Configuración del router:
BsAs#sh runn (sólo lo relevante)
!
version 12.4
!
hostname BsAs
!
ip dhcp pool DHCP
network 192.168.2.0 255.255.255.0
default-router 192.168.2.1
class RANGO
address range 192.168.2.100 192.168.2.150
!
!
ip dhcp class RANGO (esto acorta el pool de direcciones en lugar de utilizar toda la subred)
!
interface FastEthernet0/0
description LAN
ip address 192.168.2.1 255.255.255.0
duplex auto
speed auto
!
(2014) Burning minds with
networking
Rosario, Argentina