I had been using efika smarttop as an access point for a while, until recently it stopped working. First there was a problem in authentication, which I disabled to find out the root of the problem. Digging more into details, it seems there is a problem with ARP protocol in there:
Here you can see that the box cannot find out the MAC address of 192.168.64.4 even when it is receiving packets from that machine:
root@efika:~# ip addr show dev wlan0
19: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 74:f0:6d:49:cb:1c brd ff:ff:ff:ff:ff:ff
inet 192.168.64.1/24 brd 192.168.64.255 scope global wlan0
inet6 fe80::76f0:6dff:fe49:cb1c/64 scope link
valid_lft forever preferred_lft forever
root@efika:~# tcpdump -n -e -i wlan0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlan0, link-type EN10MB (Ethernet), capture size 65535 bytes
01:34:27.550369 4c:ed
60:3e:42 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has 192.168.64.1 tell 192.168.64.4, length 28
01:34:27.550593 4c:ed
60:3e:42 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has 192.168.64.1 tell 192.168.64.4, length 28
^C
2 packets captured
2 packets received by filter
0 packets dropped by kernel
root@efika:~# arp -na
? (192.168.64.4) at <incomplete> on wlan0
? (192.168.3.1) at 00:1a:80:d3:6d:d7 [ether] on eth0