Is it possible to attach a IE field to my wifi hotspot so that it appear in the iwlist output of other machine scanning it?Example: I choose 1234567891011121314151617181920 to be the additional field for my wifi hotspot (MAC address 11:22:33:44:55:66)Users scanning my wifi hotspot with command iwlist wlan0 scan, should give the output:  wlan0  Scan completed :   Cell 01 - Address: 11:22:33:44:55:66  [...]  IE: Unknown 1234567891011121314151617181920  [...]
How to add an IE field for my wifi hotspot?
wifi;wifi hotspot;iwlwifi;wpa cli;iw
IE stands for Information Element. They are transmitted as part of the beacon frames, and carry all kinds of information such as SSID, supported rates, etc.Information element                        Element ID    Length (in octets)---------------------------------------------------------------------------SSID (see 7.3.2.1)                         0             2 to 34Supported rates (see 7.3.2.2)              1             3 to 10FH Parameter Set (see 7.3.2.3)             2             7DS Parameter Set (see 7.3.2.4)             3             3CF Parameter Set (see 7.3.2.5)             4             8TIM (see 7.3.2.6)                          5             6 to 256IBSS Parameter Set (see 7.3.2.7)           6             4Country (see 7.3.2.9)                      7             8 to 256Hopping Pattern Parameters (see 7.3.2.10)  8             4Hopping Pattern Table (see 7.3.2.11)       9             6 to 256Request (see 7.3.2.12)                     10            2 to 256BSS Load (see 7.3.2.28)                    11            7EDCA Parameter Set (see 7.3.2.29)          12            20TSPEC (see 7.3.2.30)                       13            57TCLAS (see 7.3.2.31)                       14            2 to 257Schedule (see 7.3.2.34)                    15            16Challenge text (see 7.3.2.8)               16            3 to 255Reserved                                   1731Power Constraint (see 7.3.2.15)            32            3Power Capability (see 7.3.2.16)            33            4TPC Request (see 7.3.2.17)                 34            2TPC Report (see 7.3.2.18)                  35            4Supported Channels (see 7.3.2.19)          36            4 to 256Channel Switch Announcement (see 7.3.2.20) 37            5Measurement Request (see 7.3.2.21)         38            5 to 16Measurement Report (see 7.3.2.22)          39            5 to 24Quiet (see 7.3.2.23)                       40            8IBSS DFS (see 7.3.2.24)                    41            10 to 255ERP Information (see 7.3.2.13)             42            3TS Delay (see 7.3.2.32)                    43            6TCLAS Processing (see 7.3.2.33)            44            3Reserved                                   45QoS Capability (see 7.3.2.35)              46            3Reserved                                   47RSN (see 7.3.2.25)                         48            36 to 256Reserved                                   49Extended Supported Rates (see 7.3.2.14)    50            3 to 257Reserved                                   51126Extended Capabilities                      127           2 to 257Reserved                                   128220Vendor Specific (see 7.3.2.26)             221           3 to 257Reserved                                   222255Some of these information elements are vendor specific, meaning they will probably be ignored by other vendors. Reserved means it may have a standard meaning in the future, in fact some of them already have. (I'm looking at an old standard.) You can configure them in hostapd.conf# Additional vendor specific elements for Beacon and Probe Response frames# This parameter can be used to add additional vendor specific element(s) into# the end of the Beacon and Probe Response frames. The format for these# element(s) is a hexdump of the raw information elements (id+len+payload for# one or more elements)vendor_elements=dd0411223301The hex data is the of the following structure:The Element ID shall be dd, OUI is a 3 byte number allocated by IEEE, but the good news is iwlist displays all of them as unknown, except WPA (0050f2) and WPA2 (000fac).