AP advertised its basic rate set as following, don't support 6M:
Tag: Supported Rates 12(B), 18, 24, 36, 48, 54, [Mbit/sec]
Tag Number: Supported Rates (1)
Tag length: 6
Supported Rates: 12(B) (0x98)
Supported Rates: 18 (0x24)
Supported Rates: 24 (0x30)
Supported Rates: 36 (0x48)
Supported Rates: 48 (0x60)
Supported Rates: 54 (0x6c)
And Macbook pro has associated the AP successfully, which means it knows and accepts the supported rates.
Refer to 802.11 standard, RTS frames must be transmitted at one of the rates in the BSS basic rate set, both RTS and CTS frames are always transmitted at the same rate, and this rate must belong to the BSS basic rate set. But the macbook pro constant sent RTS with 6M rate:
802.11 radio information
PHY type: 802.11a (OFDM) (5)
Turbo type: Non-turbo (0)
Data rate: 6.0 Mb/s
Channel: 52
Frequency: 5260MHz
Signal strength (dBm): -54dBm
Noise level (dBm): -95dBm
Signal/noise ratio (dB): 41dB
TSF timestamp: 162236858
[Duration: 52µs]
IEEE 802.11 Request-to-send, Flags: ........C
Type/Subtype: Request-to-send (0x001b)
Frame Control Field: 0xb400
.... ..00 = Version: 0
.... 01.. = Type: Control frame (1)
1011 .... = Subtype: 11
Flags: 0x00
.... ..00 = DS status: Not leaving DS or network is operating in AD-HOC mode (To DS: 0 From DS: 0) (0x0)
.... .0.. = More Fragments: This is the last fragment
.... 0... = Retry: Frame is not being retransmitted
...0 .... = PWR MGT: STA will stay up
..0. .... = More Data: No data buffered
.0.. .... = Protected flag: Data is not protected
0... .... = Order flag: Not strictly ordered
.000 0001 0001 1010 = Duration: 282 microseconds
Receiver address: Cisco_ba:33:ee (2c:33:11:ba:33:ee)
Transmitter address: Apple_4a:24:e0 (f0:18:98:4a:24:e0)
Frame check sequence: 0x0c2d050b [unverified]
[FCS Status: Unverified]
This behavior caused the macbook pro constant ping loss. Why it sent RTS at a rate that doesn't belong to AP's basic rate set?
BTW: the macbook pro's version is 10.14.2, and 10.15.1 has the same problem as well. The AP model is Cisco AP2802i.
Tag: Supported Rates 12(B), 18, 24, 36, 48, 54, [Mbit/sec]
Tag Number: Supported Rates (1)
Tag length: 6
Supported Rates: 12(B) (0x98)
Supported Rates: 18 (0x24)
Supported Rates: 24 (0x30)
Supported Rates: 36 (0x48)
Supported Rates: 48 (0x60)
Supported Rates: 54 (0x6c)
And Macbook pro has associated the AP successfully, which means it knows and accepts the supported rates.
Refer to 802.11 standard, RTS frames must be transmitted at one of the rates in the BSS basic rate set, both RTS and CTS frames are always transmitted at the same rate, and this rate must belong to the BSS basic rate set. But the macbook pro constant sent RTS with 6M rate:
802.11 radio information
PHY type: 802.11a (OFDM) (5)
Turbo type: Non-turbo (0)
Data rate: 6.0 Mb/s
Channel: 52
Frequency: 5260MHz
Signal strength (dBm): -54dBm
Noise level (dBm): -95dBm
Signal/noise ratio (dB): 41dB
TSF timestamp: 162236858
[Duration: 52µs]
IEEE 802.11 Request-to-send, Flags: ........C
Type/Subtype: Request-to-send (0x001b)
Frame Control Field: 0xb400
.... ..00 = Version: 0
.... 01.. = Type: Control frame (1)
1011 .... = Subtype: 11
Flags: 0x00
.... ..00 = DS status: Not leaving DS or network is operating in AD-HOC mode (To DS: 0 From DS: 0) (0x0)
.... .0.. = More Fragments: This is the last fragment
.... 0... = Retry: Frame is not being retransmitted
...0 .... = PWR MGT: STA will stay up
..0. .... = More Data: No data buffered
.0.. .... = Protected flag: Data is not protected
0... .... = Order flag: Not strictly ordered
.000 0001 0001 1010 = Duration: 282 microseconds
Receiver address: Cisco_ba:33:ee (2c:33:11:ba:33:ee)
Transmitter address: Apple_4a:24:e0 (f0:18:98:4a:24:e0)
Frame check sequence: 0x0c2d050b [unverified]
[FCS Status: Unverified]
This behavior caused the macbook pro constant ping loss. Why it sent RTS at a rate that doesn't belong to AP's basic rate set?
BTW: the macbook pro's version is 10.14.2, and 10.15.1 has the same problem as well. The AP model is Cisco AP2802i.