-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 2017-03-31 11:36, jimc@xxxxxxxxxxxx wrote: > I put the station in 4 address mode. Expected packets arrive on the > access point, which sends replies back on the station clone > (wlan0.sta3), but none arrive on the station, only management frames. > --snip-- I put another machine into monitor mode. The AP appears to be sending Data packets directed to the station (in 4 address mode), when tcpdump on the AP reports that it intends to send a packet out. But tcpdump on the station consistently reports receiving a Command/Information packet instead. So it looks like hostapd is not the perpetrator. But how could a Data packet change into an Info packet on the station? Does anyone have any suggestions for how to get this working? I've appended about 100 packets (3 secs) of monitor mode output, annotated. Clearly not every packet is captured, maybe as few as half of them. Names of hosts: Diamond = monitor mode, Jacinth = AP, Xena = station. Each line has prepended the first letter of the host's name. tcpdump had the -e option, but not -v. Notes follow packet groups. These categories of packets are edited out: neighbors' traffic; beacons (except the first); most mDNS traffic; all multicast packets not involving Xena (station). James F. Carter Landline 310 397 3058 Mobile 424 230 4633 12134 Lawler Street, Los Angeles, CA, USA, 90066-1906 Email: jimc@xxxxxxxxxxxx http://www.jfcarter.net/~jimc (q.v. for GPG key) ** Starting with the first packet caught by Diamond. D 17:02:33.589355 830393950us tsft 1.0 Mb/s 2462 MHz 11b -50dB signal antenna 0 BSSID:jacinth.cft.ca.us DA:Broadcast SA:jacinth.cft.ca.us Beacon (CouchNet) [1.0* 2.0* 5.5* 11.0* 6.0 9.0 12.0 18.0 Mbit] ESS CH: 11, PRIVACY ** Jacinth beacon (all future beacons are omitted). X 17:02:33.783652 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 D 17:02:33.784253 830590478us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:33.784654 830590966us tsft 2462 MHz 11g -47dB signal antenna 0 58.5 Mb/s MCS 6 20 MHz lon GI CF +QoS RA:jacinth.cft.ca.us TA:xena.cft.ca.us DA:Broadcast SA:xena.cft.ca.us Data IV: 6f Pad 20 KeyID 0 D 17:02:33.784667 830591029us tsft 6.0 Mb/s 2462 MHz 11g -44dB signal antenna 0 RA:xena.cft.ca.us BA J 17:02:33.785190 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 J 17:02:33.785429 jacinth.cft.ca.us > xena.cft.ca.us, ethertype ARP (0x0806), length 42: Reply jacinth.cft.ca.us is-at jacinth.cft.ca.us, length 28 D 17:02:33.785890 830591526us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 DA:Broadcast BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us Data IV:682808 Pad 20 KeyID 1 D 17:02:33.785902 830592305us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA X 17:02:33.788968 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 48: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 34 ** Xena sends broadcast ARP for Jacinth, which replies to SA Xena. ** Diamond caught the reply (a Data packet). ** Xena gets an Information packet. Did not catch the Data packet. ** Assuming J, D, X's last packet are all at the same time, which is not ** quite true, D is 461usec future of J, and X is 3078usec future of D. ** Consistent with another similar subtraction shown later. D 17:02:33.886836 830693073us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment J 17:02:34.118807 jacinth.cft.ca.us > 33:33:00:00:00:fb (oui Unknown), ethertype IPv6 (0x86dd), length 152: jacinth.cft.ca.us.mdns > ff02::fb.mdns: 0 PTR (QM)? 5.8.c.9.1.b.f.f.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.f.f.ip6.arpa. (90) J 17:02:34.119211 jacinth.cft.ca.us > 01:00:5e:00:00:fb (oui Unknown), ethertype IPv4 (0x0800), length 132: jacinth.cft.ca.us.mdns > 224.0.0.251.mdns: 0 PTR (QM)? 5.8.c.9.1.b.f.f.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.f.f.ip6.arpa. (90) D 17:02:34.121963 830926922us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 DA:01:00:5e:00:00:fb (oui Unknown) BSSID:jacinth.cft.ca.us SA:jacinth.cft.ca.us Data IV:6a2808 Pad 20 KeyID 1 ** D's pkt may be one of the MDNS transmissions. Xena missed both of them. J 17:02:34.261639 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4984, length 80 J 17:02:34.261740 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4984, length 80 ** Jacinth sends 2 echo reqs to Xena, neither transmitted (no ARP replies) D 17:02:34.307134 831113234us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:34.307421 831113684us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:34.307537 831113964us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA D 17:02:34.307625 831114020us tsft 2462 MHz 11g 10dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:01:00:5e:00:00:fb (oui Unknown) SA:jacinth.cft.ca.us Data IV: 45 Pad 20 KeyID 0 D 17:02:34.307631 831114020us tsft 2462 MHz 11g 10dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:xena.cft.ca.us SA:jacinth.cft.ca.us Data IV: 46 Pad 20 KeyID 0 D 17:02:34.307634 831114020us tsft 2462 MHz 11g -47dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:xena.cft.ca.us SA:jacinth.cft.ca.us Data IV: 47 Pad 20 KeyID 0 D 17:02:34.307672 831114130us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA ** These 7 packets are probably related, but not seen at 3rd layer. X 17:02:34.310600 jacinth.cft.ca.us > 33:33:00:00:00:fb (oui Unknown), 802.3, length 158: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 144 X 17:02:34.310763 jacinth.cft.ca.us > 01:00:5e:00:00:fb (oui Unknown), 802.3, length 138: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 124 X 17:02:34.310768 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 X 17:02:34.310772 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 ** Xena received 4 Command and Info packets from Jacinth, not 3rd layer. D 17:02:34.409090 831215191us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:34.409587 831215718us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:34.409901 831216168us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment ** Jacinth sent 3 pkts to Xena, not at 3rd layer. Separate from prev 4. X 17:02:34.807801 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 D 17:02:34.808060 831614163us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:34.808335 831614613us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment J 17:02:34.809405 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 J 17:02:34.809647 jacinth.cft.ca.us > xena.cft.ca.us, ethertype ARP (0x0806), length 42: Reply jacinth.cft.ca.us is-at jacinth.cft.ca.us, length 28 X 17:02:34.813182 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 48: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 34 ** Xena ARP req for Jacinth, which replies, not caught by D, X gets Info pkt D 17:02:34.910724 831716833us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:34.911003 831717283us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment ** Can't tell what this is for. J 17:02:35.260933 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4985, length 80 J 17:02:35.261058 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4985, length 80 ** Jacinth sends 2 echo req to Xena, not transmitted because no ARP. D 17:02:35.331157 832137245us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:35.331485 832137695us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:35.331541 832137893us tsft 2462 MHz 11g 10dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:xena.cft.ca.us SA:jacinth.cft.ca.us Data IV: 49 Pad 20 KeyID 0 D 17:02:35.331545 832137893us tsft 2462 MHz 11g -46dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:xena.cft.ca.us SA:jacinth.cft.ca.us Data IV: 4a Pad 20 KeyID 0 D 17:02:35.331548 832137983us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA X 17:02:35.334633 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 X 17:02:35.334646 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 ** More chatter not at 3rd layer. D 17:02:35.433080 832239198us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:35.433380 832239648us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment ** More chatter not at 3rd layer. X 17:02:35.831650 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 D 17:02:35.831844 832637990us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:35.832158 832638440us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:35.832593 832638926us tsft 2462 MHz 11g -47dB signal antenna 0 52.0 Mb/s MCS 5 20 MHz lon GI CF +QoS RA:jacinth.cft.ca.us TA:xena.cft.ca.us DA:Broadcast SA:xena.cft.ca.us Data IV: 79 Pad 20 KeyID 0 D 17:02:35.832601 832638990us tsft 6.0 Mb/s 2462 MHz 11g -41dB signal antenna 0 RA:xena.cft.ca.us BA J 17:02:35.833250 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 J 17:02:35.833465 jacinth.cft.ca.us > xena.cft.ca.us, ethertype ARP (0x0806), length 42: Reply jacinth.cft.ca.us is-at jacinth.cft.ca.us, length 28 X 17:02:35.837026 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 48: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 34 ** Xena ARP req for Jacinth, which replies, D misses reply but Xena gets ** an Info packet. ** Traffic to/from IoT device deleted. ** Tossed 2 mdns multicasts from Jacinth. D 17:02:36.123062 832927833us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 DA:33:33:00:00:00:fb (oui Unknown) BSSID:jacinth.cft.ca.us SA:jacinth.cft.ca.us Data IV:6d2808 Pad 20 KeyID 1 D 17:02:36.124659 832929623us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 DA:01:00:5e:00:00:fb (oui Unknown) BSSID:jacinth.cft.ca.us SA:jacinth.cft.ca.us Data IV:6e2808 Pad 20 KeyID 1 D 17:02:36.150343 832956469us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:36.150725 832956919us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:36.150737 832957108us tsft 2462 MHz 11g 10dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:33:33:00:00:00:fb (oui Unknown) SA:jacinth.cft.ca.us Data IV: 4c Pad 20 KeyID 0 D 17:02:36.150769 832957108us tsft 2462 MHz 11g -46dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:01:00:5e:00:00:fb (oui Unknown) SA:jacinth.cft.ca.us Data IV: 4d Pad 20 KeyID 0 D 17:02:36.150777 832957202us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA X 17:02:36.153965 jacinth.cft.ca.us > 33:33:00:00:00:fb (oui Unknown), 802.3, length 158: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 144 X 17:02:36.153980 jacinth.cft.ca.us > 01:00:5e:00:00:fb (oui Unknown), 802.3, length 138: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 124 ** 7 pkts caught by D between J and X, X got 2 Info pkts, ** nothing at 3rd layer. Looks like X is 3.2 msec future vs. D. D 17:02:36.252312 833058416us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:36.252625 833058866us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment ** 2 pkts 2nd layer chatter between J and X. J 17:02:36.270617 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4986, length 80 J 17:02:36.270736 jacinth.cft.ca.us > xena.cft.ca.us, ethertype IPv4 (0x0800), length 114: jacinth.cft.ca.us > xena.cft.ca.us: ICMP echo request, id 14514, seq 4986, length 80 ** Jacinth sends 2 echo req to Xena, not transmitted because no ARP. X 17:02:36.360338 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 X 17:02:36.360353 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 120: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 106 ** Xena gets 2 Info pkts from Jacinth. Not caught by D. ** Bunch of IoT chatter tossed. ** Xena mdns multicast in the middle of the IoT chatter, not shown. ** Plus a printer announcement multicast from D, tossed. X 17:02:36.855654 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 D 17:02:36.855923 833661999us tsft 1.0 Mb/s 2462 MHz 11b -56dB signal antenna 0 CF +QoS BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us DA:jacinth.cft.ca.us D 17:02:36.856231 833662450us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 RA:xena.cft.ca.us Acknowledgment D 17:02:36.856664 833662996us tsft 6.0 Mb/s 2462 MHz 11g -41dB signal antenna 0 RA:xena.cft.ca.us BA J 17:02:36.857212 xena.cft.ca.us > Broadcast, ethertype ARP (0x0806), length 42: Request who-has jacinth.cft.ca.us tell xena.cft.ca.us, length 28 J 17:02:36.857440 jacinth.cft.ca.us > xena.cft.ca.us, ethertype ARP (0x0806), length 42: Reply jacinth.cft.ca.us is-at jacinth.cft.ca.us, length 28 D 17:02:36.857887 833663501us tsft 1.0 Mb/s 2462 MHz 11b -48dB signal antenna 0 DA:Broadcast BSSID:jacinth.cft.ca.us SA:xena.cft.ca.us Data IV:722808 Pad 20 KeyID 1 D 17:02:36.857901 833664223us tsft 2462 MHz 11g -46dB signal antenna 0 65.0 Mb/s MCS 7 20 MHz lon GI CF +QoS RA:xena.cft.ca.us TA:jacinth.cft.ca.us DA:xena.cft.ca.us SA:jacinth.cft.ca.us Data IV: 52 Pad 20 KeyID 0 D 17:02:36.857904 833664281us tsft 24.0 Mb/s 2462 MHz 11g -47dB signal antenna 0 RA:jacinth.cft.ca.us BA X 17:02:36.860982 jacinth.cft.ca.us > xena.cft.ca.us, 802.3, length 48: LLC, dsap 802.1B I (0x02) Group, ssap Null (0x00) Command, ctrl 0x0000: Information, send seq 0, rcv seq 0, Flags [Command], length 34 ** Xena sends ARP req for Jacinth, which replies, D caught reply, ** Xena gets an Info packet. -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEwCO3Ffd4f3UN9nvKddigLE9RfKkFAljr5sAACgkQddigLE9R fKkuSAgAhYWqWHqRgzWPpLVfAzHy+TU5jzMBRVozge8vi3jReng5uIntwWENmaEQ i8QeG6TPH971a0+BHtGImeMz6BWe+t8za1aXA/JOnWlHS2QiDam1OT5IrgYW5+rk sYp6gYZVluK04AHMnlk6Bwv658Pfedx36kclY9o+vqTrvAv8fJo32YwbesUw6xaM nWfkzG1SP/oJQEv9YcSl+KTvclReOWesOAOh9dZ1nBSyoZ6M9ftyF0XnG5ANyY6J /R5VgHsgniENxGPmkjeBlOftEKvREOCTpW+3V06nLuL0tEa6i4GZEEFwJ/90W/Co aSK3wl5mAVDU6DeqR0Zmv58GbF/U3w== =cjKw -----END PGP SIGNATURE----- _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
