i have a question to the output of iwlist scan. for instance i have the following result.
There are multiple entries with IE. What does the IE stand for? Becasue there are multiple entries i guess there are different encryption options for this Wifi. What are all options can be displayed there? "WPA Version 1","IEEE 802.11i/WPA2 Version 1","unkonw" what is about WEP? Or EAP? How this will be displayed?
Cell 01 - Address: 00:1F:F3:02:04:81
ESSID:"Apple Network"
Mode:Master
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=42/100 Signal level:-84 dBm Noise level=-127 dBm
Encryption key:on
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: Unknown: 2D1A2C0217FFFF000000000000000000000000000000000000000000
IE : Information Elements
Refer to Management Frames,
Management frames are quite flexible. Most of the data contained in
the frame body uses fixed-length fields called fixed fields and
variable-length fields called information elements. Information elements are blobs of data of varying size. Each data blob
is tagged with a type number and a size, and it is understood that an
information element of a certain type has its data field interpreted
in a certain way. New information elements can be defined by newer
revisions to the 802.11 specification;
IEEE 802.11i-2004 is standard that specifies security mechanisms for wireless networks.
Wi-Fi Protected Access (WPA) is security protocol and security certification program.
sorry I can't find iwlist result with WEP and EAP.....
How about use iw command? The n mode on “iwlist wlan0 scan”
Related
Guys i have a little problem. I have 2 csv files, i want to copy some data from one csv to another where id is the same. For this i use vlookupfunction but something is not good.
The orginal string in orginal csv is:
48 Port Managed Layer 3 Gigabit Ethernet Switch with optional 10GigE uplink and 802.3af and Legacy Power over Ethernet. Includes 48 - Copper Gigabit (1000Base-T) access ports and 2 - High Speed Expansion Slots. Provides up to 370 watts of 802.3af compliant power. Features include 802.1Q VLANs, GVRP, 802.1p QoS, 802.1w Rapid Spanning Tree, 802.3ad Link Aggregation, Auto MDI/MDI-X, CLI, HTTP GUI, SSH, SSL, RADIUS, SNMP. 19" Rackmount 1U housing. Includes AC PoE power supply. Supported expansion modules: Dual Stacking XIM (4700470F1, 4700470F2, 4700470F5), Dual SFP XIM (1700473F1), Dual SFP+ XIM (1700471F1).
And when i use this function
=IFERROR(VLOOKUP($A2,osnova.csv!$B$2:$AD$1660,8,0),IF(G2="","",G2))
I get this string:
48 Port Managed Layer 3 Gigabit Ethernet Switch with optional 10GigE uplink and 802.3af and Legacy Power over Ethernet. Includes 48 - Copper Gigabit (1000Base-T) access ports and 2 - High Speed Expansion Slots. Provides up to 370 watts of 802.3af compliant power. Features include 802.1Q VLANs, GVRP, 802.1p QoS, 802.1w Rapid Spanning Tree, 802. 19" Rackmount 1U housing. Includes AC PoE power supply. Supported expansion modules: Dual Stacking XIM (4700470F1, 4700470F2, 4700470F5), Dual SFP XIM (1700473F1), Dual SFP+ XIM (1700471F1).
The difference is that i have in orginal string this part and in the copied version i lose that part:
.3ad Link Aggregation, Auto MDI/MDI-X, CLI, HTTP GUI, SSH, SSL, RADIUS, SNMP.
Can someone help me with this? Did i do something wrong in my function?
Your version of Excel must be hitting the character limit of VLOOKUP. You should not be using this function in the first place, it's broken and it sucks. Consider using much superior INDEX/MATCH combination =index(osnova.csv!$H$1660, match($A2,osnova.csv!$B$2,0)).
I feel like both are used to identify logical channel that a physical channel is divided into. Is there any difference?
Short answer:
Both terms are relevant to Bluetooth Logical Links definitions.
LT Address is defined in Link Control; it is being used In the packet header.
In general, It allows a Bluetooth (BR/EDR) slave to determine that a certain packet was addressed to it.
LLID is defined in the packet payload header and is used to distinguish between:
ACL-C (Link Management Protocol) message
ACL-U (L2CAP - Logical Link Control and Adaptation Protocol) message
Detailed answer (all page references address the BT Spec 5.0):
LT Address is defined in the Bluetooth Baseband Specification and stands for Logical Transport Address.
It is defined in Link Control layer for the master to be able to address its various slaves within the piconet.
Each slave is assigned with a unique 3-bit LT_ADDR (page 390):
The primary LT_ADDR shall be assigned by the master to the slave when
the slave is activated. This is either at connection establishment or
role switch, when the primary LT_ADDR is carried in the FHS payload.
LLID term is defined in ACL-C and ACL-U (=> L2CAP) logical links:
It is included in the packet payload header to determine if a packet is ACL-C (LMP) or ACL-U (L2CAP):
ACL-C (page 398):
The ACL-C and ASB-C logical links are indicated by the LLID code 11b
in the payload header.
ACL-U (page 399):
For fragmented messages, the start packet shall use anLLID code of
10b in the payload header. Remaining continuation packets shall use
LLID code 01b. If there is no fragmentation, all packets shall use
the LLID start code 10b.
There’s another usage of the LLID term in context of Bluetooth Low Energy (LE) which is not covered here.
The Logical Link Control and Adaptation Layer Protocol (L2CAP) is layered over the Baseband Protocol and resides in the data link layer. It provides connection-oriented and connectionless data services to upper layer protocols with protocol multiplexing capability, segmentation and reassembly operation, and group abstractions. L2CAP permits higher level protocols and applications to transmit and receive L2CAP data packets up to 64 kilobytes in length.
Fig1: L2CAP architecture block
Link Controller (LC)
The standard data packet used at the LC level comprises an Access Code, Packet Header, Payload Header, Payload and CRC. This standard packet will be used to encompass data to and from the upper-layers of the protocol stack.
Fig1: Packet structure at LC
Packet Header
Header comprises of six fields LT_ADDR,TYPE,FLOW,ARQN,SEQN and HEC
LT_ADDR (Logical Transport Address) : LT_ADDR comprises of a 3-bit field, which denotes an active slave within a piconet (Note: that the master is not assigned a LT_ADDR).
Payload
LLID (Logical Link Identifier) : Within such logical transports, the logical link is identified by the LLID bits in the payload header of baseband packets that carry a data payload.
Ref :
BLE5-Stack User's Guide
Developing Practical Wireless Applications
Bluetooth Specification - Vol 0
For BLE advertising type LOCAL_NAME_COMPLETE, is there a minimum length requirement?
I could not find any length specification in the spec (other than it needs to fit in the advertising packet of 31 bytes minus anything else already in the advertisement packet), but am running into an issue where it may seem that there is. I wanted to confirm here.
According to the BLUETOOTH SPECIFICATION Version 4.0 [Vol 3] section 12.1:
...The Device Name characteristic value shall be 0 to 248 octets in length. A
device shall have only one instance of the Device Name characteristic.
But since the AD packet is limited to 31 bytes then I guess that if it's too big then one should broadcast the shortened name instead of full name (different AD types)
So it seems like there is no limitations on a minimum size. Hope it helped.
I'm implementing a LIN protocol on a Linux SBC that transmits over a UART. I don't have time to develop a complete LIN stack, so I'm just implementing a frame structure for messages as defined by the protocol. The problem is that the protocol requires a "Break" field which makes the slave devices on the bus listen. This field consists of zeros for 13 bit-times. Any ideas how to send zeros 13 bit-times over UART, when serial data transmission requires complete bytes?
Per Wiki:
LIN (Local Interconnect Network) is a serial network protocol used for
communication between components in vehicles. The need for a cheap
serial network arose as the technologies and the facilities
implemented in the car grew, while the CAN bus was too expensive to
implement for every component in the car. European car manufacturers
started using different serial communication topologies, which led to
compatibility problems.
If you would have paid attention at class you would have known that:
Data is transferred across the bus in fixed form messages of
selectable lengths. The master task transmits a header that consists
of a break signal followed by synchronization and identifier fields.
The slaves respond with a data frame that consists of between 2, 4 and
8 data bytes plus 3 bytes of control information.
You should just send an echo of 0x0000 following by CR/LF.
I need to read serial number of MiFare card usin WinSCard. I am able to read 7B UID from the MiFare card.
The confusion is that i dont know if the UID and the serial number of
MiFare card are same?!!
I have googled the issue but only could get partial success. I found a question on stackoverflow also but it did not help.
I found a document of NXP online which says UID and serial number are different. (on page number 3, line number 5)
There is an application of OmniKey that reads the serial number of the card, and it also returns UID only.
NXP documentation says UID <> Serial Number and a other standard OmniKey application returns UID as Serial Number.
I have started pulling my hair off on the issue. I'd greatly appreciate if anyone could help.
Each smart card contains an integrated chip with a unique permanent identification (UID) number burned-in during the manufacturing process. This UID is often referred to as the Card Serial Number (CSN). The card serial number is not encrypted and any reader that is ISO compliant can read the card serial number.
Edit 1:
Mifare Card Serial Number is the unique identifier defined in ISO 14443-3A. There are 3 types of UID defined in the standard - single (4 bytes), double (7 bytes) and triple (10 bytes). Only in first versions of the Mifare card, the UID was 4 bytes but now have migrated to 7 bytes.
EDIT 2:
It might be helpful to you...
What is the difference between a 4 byte UID and a 4 byte ID?
A 4 byte UID is an identifier which has been assigned by the card
manufacturer using a controlled database. This database ensures that a
single identifier is not used twice. In contradiction, a 4 byte ID is an
identifier which may be assigned to more then one contactless chip over
the production time of a product so that more then one card with the same
identified may be deployed into one particular contactless system.
The differentiation in this case comes from the fact that a "Serial Number" implies that the numbers are a series, thus sequentially assigned.
MIFARE cards have Unique Identification Numbers (or in short UID), which are generated by an internal rule which is not necessarily sequential. This means that if you see a card with UID 01020304050607 it does not mean that there are at least that many cards produced so far.
If you ever see someone referring to the Card Serial Number, they are in fact referring to the UID.
The only last confusion can come from the fact that MIFARE cards can be configured to return Random IDs during activation. If that is the case, you would get different "UID" each time you activate the card. In that scenario you need to read the data contained in Block 0 (for which you will need to know the key to sector 0) to get the real UID of the card.
For DesFire cards:
UID is analogous to ethernet MAC address. It is assigned by the chip
manufacturer from a database. Everyone who creates applications for
the card has access to the UID.
The Card Serial Number is specific
to the application loaded on to the card. It can only be accessed by
that application via an encryption key. If the card had several applications loaded on to
it (unlikely but possible), then each could have a different CSN.