17. DHCP Based on DORA model:
Discovery, Offer, Response, Acknowledgement
18. From Client To 255.255.255.255:67
Message type: Boot Request (1)
Hardware type: Ethernet
Transaction ID: 0x2da9d67f
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 80:00:27:bc:59:29
Magic cookie: DHCP
Option: (t=53,l=1) DHCP Message Type = DHCP Request
Option: (t=12,l=9) Host Name = "testmachine"
Option: (t=55,l=17) Parameter Request List
1 = Subnet Mask
2 = Time Offset
3 = Router
6 = Domain Name Server
12 = Host Name
15 = Domain Name
26 = Interface MTU
28 = Broadcast Address
42 = Network Time Protocol Servers
44 = NetBIOS over TCP/IP Name Server
47 = NetBIOS over TCP/IP Scope
119 = Domain Search [TODO:RFC3397]
121 = Classless Static Route
249 = Private/Classless Static Route (Microsoft)
252 = Private/Proxy autodiscovery
End Option
19. From Server to [MAC]:68
Message type: Boot Reply (2)
Hardware type: Ethernet
Transaction ID: 0x2da9d67f
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 10.20.42.5
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: 80:00:27:bc:59:29
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (t=53,l=1) DHCP Message Type = DHCP ACK
Option: (t=54,l=4) DHCP Server Identifier = 10.20.40.1
Option: (t=51,l=4) IP Address Lease Time = 600
Option: (t=1,l=4) Subnet Mask = 255.255.252.0
Option: (t=3,l=4) Router = 10.20.40.1
Option: (t=6,l=8) Domain Name Server
IP Address: 10.20.40.1
IP Address: 10.20.40.2
End Option
20. From Server to [MAC]:68
Message type: Boot Reply (2)
Hardware type: Ethernet
Transaction ID: 0x2da9d67f
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 10.20.42.5
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: 80:00:27:bc:59:29
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (t=53,l=1) DHCP Message Type = DHCP ACK
Option: (t=54,l=4) DHCP Server Identifier = 10.20.40.1
--> Option: (t=51,l=4) IP Address Lease Time = 600
Option: (t=1,l=4) Subnet Mask = 255.255.252.0
Option: (t=3,l=4) Router = 10.20.40.1
Option: (t=6,l=8) Domain Name Server
IP Address: 10.20.40.1
IP Address: 10.20.40.2
End Option
21. From Client To 255.255.255.255:67
Message type: Boot Request (1)
Hardware type: Ethernet
Transaction ID: 0x2da9d67f
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 80:00:27:bc:59:29
Magic cookie: DHCP
Option: (t=53,l=1) DHCP Message Type = DHCP Request
--> Option: (t=50,l=4) Requested IP Address = 10.20.42.5
Option: (t=12,l=9) Host Name = "testmachine"
Option: (t=55,l=17) Parameter Request List
1 = Subnet Mask
2 = Time Offset
3 = Router
6 = Domain Name Server
12 = Host Name
15 = Domain Name
26 = Interface MTU
28 = Broadcast Address
42 = Network Time Protocol Servers
44 = NetBIOS over TCP/IP Name Server
47 = NetBIOS over TCP/IP Scope
119 = Domain Search [TODO:RFC3397]
121 = Classless Static Route
249 = Private/Classless Static Route (Microsoft)
252 = Private/Proxy autodiscovery
End Option
26. dn: uid=john,ou=People,dc=example,dc=com
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
uid: john
sn: Doe
givenName: John
cn: John Doe
displayName: John Doe
uidNumber: 10000
gidNumber: 5000
userPassword: johnldap
gecos: John Doe
loginShell: /bin/bash
homeDirectory: /home/john
Taken from Ubuntu Server Guide for 12.04
27. dn: ou=People,dc=example,dc=com
objectClass: organizationalUnit
ou: People
dn: ou=Groups,dc=example,dc=com
objectClass: organizationalUnit
ou: Groups
dn: cn=miners,ou=Groups,dc=example,dc=com
objectClass: posixGroup
cn: miners
gidNumber: 5000
Taken from Ubuntu Server Guide for 12.04
28. dn: uid=john,ou=People,dc=example,dc=com
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
uid: john
sn: Doe
givenName: John
cn: John Doe
displayName: John Doe
uidNumber: 10000
gidNumber: 5000
--> userPassword: johnldap
gecos: John Doe
loginShell: /bin/bash
homeDirectory: /home/john
Taken from Ubuntu Server Guide for 12.04
30. This is a Kerberos ticket:
$ klist
Ticket cache: FILE:/tmp/krb5cc_1000
Default principal: user@NETWORK
Valid Starting Expires Service principal
28/09/12 12:44:10 28/09/12 22:44:10 krbtgt/NETWORK@NETWORK
renew until 29/09/12 12:44:09
33. _kerberos._udp.EXAMPLE.COM. IN SRV 10 0 88 kdc1.example.com.
_kerberos._udp.EXAMPLE.COM. IN SRV 20 0 88 kdc2.example.com.
_kerberos-master._udp.EXAMPLE.COM. IN SRV 0 0 88 kdc1.example.com.
_kerberos-adm._tcp.EXAMPLE.COM. IN SRV 0 0 749 kdc1.example.com.
_kpasswd._udp.EXAMPLE.COM. IN SRV 0 0 464 kdc1.example.com.
Taken from
"http://www.rjsystems.nl/en/2100-dns-discovery-kerberos.php#srvr"
34. $ host -t SRV _kerberos._udp
_kerberos._udp.example.com has SRV record 20 0 88 kdc2.example.com.
_kerberos._udp.example.com has SRV record 10 0 88 kdc1.example.com.
Taken from
"http://www.rjsystems.nl/en/2100-dns-discovery-kerberos.php#srvr"