What is this broadcast traffic from OpenWrt APs?

ishan · April 30, 2023, 10:47am

Hi,

All of my openwrt access points running 22.xx regularly send broadcast traffic to 255.255.255.255. Wireshark doesn't parse it and I am not sure what is it?

All of these access points are operating as Dumb APs, Moving traffic between router and SSIDs in different VLANs.

I have included contents of 1 such packet here,

10.0.99.12(Openwrt 22.03 access point) -> 255.255.255.255 


0000   ff ff ff ff ff ff 10 27 f5 7d af a7 08 00 45 00   .......'.}....E.
0010   05 dc 0b 18 20 00 40 11 dc ed 0a 00 63 0c ff ff   .... .@.....c...
0020   ff ff 41 50 41 50 12 0c 60 e4 00 00 12 04 00 00   ..APAP..`.......
0030   00 08 11 1b 0e 52 01 00 00 08 00 05 63 e9 02 00   .....R......c...
0040   11 f0 00 00 02 cc 00 00 00 12 68 6f 73 74 61 70   ..........hostap
0050   64 2e 77 6c 61 6e 30 00 00 00 06 00 00 0c 41 6e   d.wlan0.......An
0060   75 57 69 66 69 00 01 00 00 08 00 00 09 94 04 00   uWifi...........
0070   00 08 00 00 00 00 05 00 00 08 00 00 00 08 02 00   ................
0080   00 08 00 00 00 01 07 00 00 08 00 00 00 00 0c 00   ................
0090   00 08 00 00 00 51 0b 00 00 08 00 00 00 09 0a 00   .....Q..........
00a0   00 0a 10 27 f5 7d af a8 00 00 08 00 00 68 81 00   ...'.}.......h..
00b0   00 64 00 00 00 00 83 00 00 1a 00 00 00 00 31 30   .d............10
00c0   3a 32 37 3a 66 35 3a 37 64 3a 61 66 3a 61 38 00   :27:f5:7d:af:a8.
00d0   00 00 83 00 00 10 00 00 00 00 41 6e 75 57 69 66   ..........AnuWif
00e0   69 00 83 00 00 2d 00 00 00 00 31 30 32 37 66 35   i....-....1027f5
00f0   37 64 61 66 61 38 65 66 30 39 30 30 30 30 35 31   7dafa8ef09000051
0100   30 39 30 37 30 36 30 33 30 30 30 39 30 30 00 00   09070603000900..
0110   00 00 03 00 01 fc 00 00 00 38 00 00 00 0a c2 ed   .........8......
0120   e5 6c ec 6e 00 00 04 00 00 05 00 00 00 00 01 00   .l.n............
0130   00 08 ff ff ff a8 03 00 00 08 00 00 17 93 05 00   ................
0140   00 08 0f 28 cc 57 02 00 00 08 00 01 bd 2d 00 00   ...(.W.......-..
0150   00 38 00 00 00 0a 4a 84 26 52 de 35 00 00 04 00   .8....J.&R.5....
0160   00 05 00 00 00 00 01 00 00 08 ff ff ff a7 03 00   ................
0170   00 08 00 00 d6 48 05 00 00 08 0f 28 cc 57 02 00   .....H.....(.W..
0180   00 08 00 00 fe 78 00 00 00 38 00 00 00 0a aa 56   .....x...8.....V
0190   6c 22 e6 05 00 00 04 00 00 05 00 00 00 00 01 00   l"..............
01a0   00 08 ff ff ff a7 03 00 00 08 00 00 dc 59 05 00   .............Y..
01b0   00 08 0f 28 cc 57 02 00 00 08 00 00 f8 67 00 00   ...(.W.......g..
01c0   00 38 00 00 00 0a 2e 4e 33 62 d1 0e 00 00 04 00   .8.....N3b......
01d0   00 05 00 00 00 00 01 00 00 08 ff ff ff a6 03 00   ................
01e0   00 08 00 00 f7 1f 05 00 00 08 0f 28 cc 57 02 00   ...........(.W..
01f0   00 08 00 00 dd a1 00 00 00 38 00 00 00 0a 94 53   .........8.....S
0200   30 3b 44 df 00 00 04 00 00 05 00 00 00 00 01 00   0;D.............
0210   00 08 ff ff ff c2 03 00 00 08 00 01 2f 25 05 00   ............/%..
0220   00 08 0f 28 cc 57 02 00 00 08 00 00 a5 9b 00 00   ...(.W..........
0230   00 38 00 00 00 0a c2 ed e5 16 95 94 00 00 04 00   .8..............
0240   00 05 00 00 00 00 01 00 00 08 ff ff ff a8 03 00   ................
0250   00 08 00 01 35 3f 05 00 00 08 0f 28 cc 57 02 00   ....5?.....(.W..
0260   00 08 00 00 9f 81 00 00 00 38 00 00 00 0a da a1   .........8......
0270   19 41 17 92 00 00 04 00 00 05 00 00 00 00 01 00   .A..............
0280   00 08 ff ff ff a9 03 00 00 08 00 01 ad ef 05 00   ................
0290   00 08 0f 28 cc 57 02 00 00 08 00 00 26 d1 00 00   ...(.W......&...
02a0   00 38 00 00 00 0a 1e 6c bd 54 b7 55 00 00 04 00   .8.....l.T.U....
02b0   00 05 00 00 00 00 01 00 00 08 ff ff ff bb 03 00   ................
02c0   00 08 00 01 8f 6b 05 00 00 08 0f 28 cc 57 02 00   .....k.....(.W..
02d0   00 08 00 00 45 55 00 00 00 38 00 00 00 0a 94 14   ....EU...8......
02e0   7a 72 8b f8 00 00 04 00 00 05 01 00 00 00 01 00   zr..............
02f0   00 08 ff ff ff c3 03 00 00 08 00 00 03 e3 05 00   ................
0300   00 08 00 00 00 00 02 00 00 08 00 01 d0 dd 00 00   ................
0310   02 cc 00 00 00 14 68 6f 73 74 61 70 64 2e 77 6c   ......hostapd.wl
0320   61 6e 30 2d 31 00 06 00 00 0b 50 4d 57 69 66 69   an0-1.....PMWifi
0330   00 00 01 00 00 08 00 00 09 94 04 00 00 08 00 00   ................
0340   00 00 05 00 00 08 00 00 00 08 02 00 00 08 00 00   ................
0350   00 00 07 00 00 08 00 00 00 00 0c 00 00 08 00 00   ................
0360   00 51 0b 00 00 08 00 00 00 09 0a 00 00 0a 12 27   .Q.............'
0370   f5 7d af a8 00 00 08 00 00 68 81 00 00 64 00 00   .}.......h...d..
0380   00 00 83 00 00 1a 00 00 00 00 31 32 3a 32 37 3a   ..........12:27:
0390   66 35 3a 37 64 3a 61 66 3a 61 38 00 00 00 83 00   f5:7d:af:a8.....
03a0   00 0f 00 00 00 00 50 4d 57 69 66 69 00 00 83 00   ......PMWifi....
03b0   00 2d 00 00 00 00 31 32 32 37 66 35 37 64 61 66   .-....1227f57daf
03c0   61 38 65 66 30 39 30 30 30 30 35 31 30 39 30 37   a8ef090000510907
03d0   30 36 30 33 30 30 30 39 30 30 00 00 00 00 03 00   0603000900......
03e0   01 fc 00 00 00 38 00 00 00 0a c2 ed e5 6c ec 6e   .....8.......l.n
03f0   00 00 04 00 00 05 00 00 00 00 01 00 00 08 ff ff   ................
0400   ff a8 03 00 00 08 00 00 17 91 05 00 00 08 0f 28   ...............(
0410   cc 57 02 00 00 08 00 01 bd 2f 00 00 00 38 00 00   .W......./...8..
0420   00 0a 4a 84 26 52 de 35 00 00 04 00 00 05 00 00   ..J.&R.5........
0430   00 00 01 00 00 08 ff ff ff a7 03 00 00 08 00 00   ................
0440   d6 47 05 00 00 08 0f 28 cc 57 02 00 00 08 00 00   .G.....(.W......
0450   fe 79 00 00 00 38 00 00 00 0a aa 56 6c 22 e6 05   .y...8.....Vl"..
0460   00 00 04 00 00 05 00 00 00 00 01 00 00 08 ff ff   ................
0470   ff a7 03 00 00 08 00 00 dc 57 05 00 00 08 0f 28   .........W.....(
0480   cc 57 02 00 00 08 00 00 f8 69 00 00 00 38 00 00   .W.......i...8..
0490   00 0a 2e 4e 33 62 d1 0e 00 00 04 00 00 05 00 00   ...N3b..........
04a0   00 00 01 00 00 08 ff ff ff a6 03 00 00 08 00 00   ................
04b0   f7 1e 05 00 00 08 0f 28 cc 57 02 00 00 08 00 00   .......(.W......
04c0   dd a2 00 00 00 38 00 00 00 0a 2a 70 f5 eb 28 70   .....8....*p..(p
04d0   00 00 04 00 00 05 00 00 00 00 01 00 00 08 ff ff   ................
04e0   ff a8 03 00 00 08 00 01 15 9b 05 00 00 08 0f 28   ...............(
04f0   cc 57 02 00 00 08 00 00 bf 25 00 00 00 38 00 00   .W.......%...8..
0500   00 0a 94 53 30 3b 44 df 00 00 04 00 00 05 00 00   ...S0;D.........
0510   00 00 01 00 00 08 ff ff ff c2 03 00 00 08 00 01   ................
0520   2f 23 05 00 00 08 0f 28 cc 57 02 00 00 08 00 00   /#.....(.W......
0530   a5 9d 00 00 00 38 00 00 00 0a c2 ed e5 16 95 94   .....8..........
0540   00 00 04 00 00 05 00 00 00 00 01 00 00 08 ff ff   ................
0550   ff a8 03 00 00 08 00 01 35 3d 05 00 00 08 0f 28   ........5=.....(
0560   cc 57 02 00 00 08 00 00 9f 83 00 00 00 38 00 00   .W...........8..
0570   00 0a da a1 19 41 17 92 00 00 04 00 00 05 00 00   .....A..........
0580   00 00 01 00 00 08 ff ff ff a9 03 00 00 08 00 01   ................
0590   ad ed 05 00 00 08 0f 28 cc 57 02 00 00 08 00 00   .......(.W......
05a0   26 d3 00 00 00 38 00 00 00 0a 1e 6c bd 54 b7 55   &....8.....l.T.U
05b0   00 00 04 00 00 05 00 00 00 00 01 00 00 08 ff ff   ................
05c0   ff bb 03 00 00 08 00 01 8f 6a 05 00 00 08 0f 28   .........j.....(
05d0   cc 57 02 00 00 08 00 00 45 56 00 00 02 c4 00 00   .W......EV......
05e0   00 14 68 6f 73 74 61 70 64 2e                     ..hostapd.

lleachii · April 30, 2023, 12:49pm

Do you have any kind of roaming enabled across APs?

Can you show WiFi config?

ishan · April 30, 2023, 1:04pm

Do you have any kind of roaming enabled across APs?

Yes, I use 802.11 k/v/r across all access points.

Can you show WiFi config?

Here it is,


config wifi-device 'radio0'
	option type 'mac80211'
	option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
	option band '2g'
	option cell_density '0'
	option country 'IN'
	option bssid '1e:27:f5:7d:af:a8'
	option ieee80211k '1'
	option ieee80211r '1'
	option ieee80211v '1'
	option logger_syslog_level '1'
	option htmode 'HT40'
	option channel 'auto'

config wifi-device 'radio1'
	option type 'mac80211'
	option path '1e140000.pcie/pci0000:00/0000:00:01.0/0000:02:00.0'
	option band '5g'
	option cell_density '0'
	option country 'IN'
	option ieee80211k '1'
	option ieee80211r '1'
	option ieee80211v '1'
	option logger_syslog_level '1'
	option htmode 'VHT80'
	option channel 'auto'

config wifi-iface 'wifinet0'
	option device 'radio0'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan30'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'AnuWifi'
	option dtim_period '3'
	option ft_over_ds '0'
	option disabled '1'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '902F'

config wifi-iface 'wifinet1'
	option device 'radio1'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan30'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'AnuWifi'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '902F'

config wifi-iface 'wifinet2'
	option device 'radio0'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan40'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'PMWifi'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '29D0'

config wifi-iface 'wifinet3'
	option device 'radio1'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan40'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'PMWifi'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '29D0'

config wifi-iface 'wifinet4'
	option device 'radio0'
	option mode 'ap'
	option ssid 'PJ'
	option encryption 'psk2+ccmp'
	option network 'vlan20'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain 'AFB2'

config wifi-iface 'wifinet5'
	option device 'radio1'
	option mode 'ap'
	option ssid 'PJ'
	option encryption 'psk2+ccmp'
	option network 'vlan20'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain 'AFB2'

config wifi-iface 'wifinet6'
	option device 'radio0'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan10'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'SJHome'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '0683'

config wifi-iface 'wifinet7'
	option device 'radio1'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan10'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option ssid 'SJHome'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '0683'

config wifi-iface 'wifinet8'
	option device 'radio0'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan60'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option isolate '1'
	option ssid 'Ze Guest'
	option disabled '1'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain 'B77E'

config wifi-iface 'wifinet9'
	option device 'radio1'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan60'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option isolate '1'
	option ssid 'Ze Guest'
	option dtim_period '3'
	option ft_over_ds '0'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain 'B77E'

config wifi-iface 'wifinet10'
	option device 'radio0'
	option mode 'ap'
	option encryption 'psk2+ccmp'
	option network 'vlan70'
	option ieee80211r '1'
	option ft_psk_generate_local '1'
	option isolate '1'
	option ssid 'jnointernet'
	option disabled '0'
	option dtim_period '3'
	option ft_over_ds '0'
	option hidden '1'
	option ieee80211k '1'
	option time_advertisement '2'
	option time_zone 'IST-5:30'
	option reassociation_deadline '2000'
	option wnm_sleep_mode '1'
	option bss_transition '1'
	option mobility_domain '4669'

lleachii · April 30, 2023, 1:23pm

AnuWifi
PmWifi
broadcasting on a TP-Link

ishan · April 30, 2023, 1:33pm

sorry, I still don't quite get it.
My question was broader and I am trying to understand what exactly is in these packets?
Why is it a broadcast packet? And what is the purpose of hostapd on my APs sending these packets.

ishan · July 25, 2023, 10:00am

The packet I shared above was part of a bigger UDP payload sent from <ap>:16270 -> 255.255.255.255:16270.

It was sent by usteer. In my usteer config, I have set local mode to 0. It broadcasts blobs across the network which I guess is read by other usteer instances on the network. [1]

[1] https://github.com/blogic/usteer

system · August 4, 2023, 10:01am

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