Release Notes

79 | aaa derivation-rules Dell Networking W-Series ArubaOS 6.4.x| Reference Guide
The device identification feature allows you to assign a user role or VLAN to a specific device type by identifying
a DHCP option and signature for that device. If you create a user rule with the DHCP-Option rule type, the first
two characters in the Value field must represent the hexadecimal value of the DHCP option that this rule
should match, while the rest of the characters in the Value field indicate the DHCP signature the rule should
match. To create a rule that matches DHCP option 12 (host name), the first two characters of the in the Value
field must be the hexadecimal value of 12, which is 0C. To create a rule that matches DHCP option 55, the first
two characters in the Value field must be the hexadecimal value of 55, which is 37.
The following table describes some of the DHCP options that are useful for assigning a user role or VLAN.
DHCP Option Description Hexidecimal Equivalent
12 Host name 0C
55 Parameter Request List 37
60 Vendor Class Identifier 3C
81 Client FQDN 51
To identify DHCP strings used by an individual device, access the command-line interface in config mode and
issue the following command to include DHCP option values for DHCP-DISCOVER and DHCP-REQUEST frames
in the controller’s log files:
logging level debugging network process dhcpd
Now, connect the device you want to identify to the network, and issue the CLI command show log network.
The sample below is an example of the output that may be generated by this command.
Be aware that each device type may not have a unique DHCP fingerprint signature. For example, devices from
different manufacturers may use vendor class identifiers that begin with similar strings. If you create a DHCP-Option
rule that uses the starts-with condition instead of the equals condition, the rule may assign a role or VLAN to more
than one device type.
(host) (config) #show log network all | include DISCOVER
Feb 26 02:50:34 :202534: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan1: DISCOVER 00:19:d2:01:0b:84
Options 74:01 3d:010019d2010b84 0c:736861626172657368612d39393730 3c:4d53465420352e30
37:010f03062c2e2f1f21f92b
Feb 26 02:50:42 :202534: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan1: DISCOVER 00:19:d2:01:0b:84
Options 74:01 3d:010019d2010b84 0c:736861626172657368612d39393730 3c:4d53465420352e30
37:010f03062c2e2f1f21f92b
Feb 26 02:50:42 :202534: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan1: DISCOVER 00:19:d2:01:0b:84
Options 74:01 3d:010019d2010b84 0c:736861626172657368612d39393730 3c:4d53465420352e30
37:010f03062c2e2f1f21f92b
Feb 26 02:53:03 :202534: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan10: DISCOVER
00:26:c6:52:6b:7c Options 74:01 3d:010026c6526b7c 0c:41525542412d46416c73653232
3c:4d53465420352e30 37:010f03062c2e2f1f21f92b 2b:dc00
...
(host) (config) #show log network all| include REQUEST
Feb 26 02:53:04 :202536: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan10: REQUEST 00:26:c6:52:6b:7c
reqIP=10.10.10.254 Options 3d:010026c6526b7c 36:0a0a0a02 0c:41525542412d46416c73653232
51:00000041525542412d46416c736532322e73757279612e636f6d 3c:4d53465420352e30
37:010f03062c2e2f1f21f92b 2b:dc0100
Feb 26 02:53:04 :202536: <DBUG> |dhcpdwrap| |dhcp| Datapath vlan10: REQUEST 00:26:c6:52:6b:7c
reqIP=10.10.10.254 Options 3d:010026c6526b7c 36:0a0a0a02 0c:41525542412d46416c73653232
51:00000041525542412d46416c736532322e73757279612e636f6d 3c:4d53465420352e30
37:010f03062c2e2f1f21f92b 2b:dc0100