I create an open ad-hoc wlan by using
iwconfig (I have the same issue with
wpa_supplicant as well). there are 4 nodes on the network as seen on the figure below. The nodes run ubuntu 12.04 and debian squeeze, and have 3.7.1, 3.5 and 3.2 kernels. I use two different usb dongle brands (TP link and ZCN) that all have AR9271 chipset and
ath9k_htc driver (here is lsusb output and ethtool output).
The problem I am experiencing is that two nodes (
10.0.0.5) which have TP link usb wifi dongles can ping any node on the network, and vice-versa. However, the other nodes (
10.0.0.7) that have ZCN wifi dongle cannot ping each other, but they have no problem communicating with TP-link wifi modules.
tcpdump shows that
10.0.0.7 cannot see their arp-request, e.g.
20:37:52.470305 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28 20:37:53.463713 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28 20:37:54.463622 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28 20:37:55.472868 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28 20:37:56.463439 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28 20:37:57.463469 ARP, Request who-has 10.0.0.7 tell 10.0.0.6, length 28
but they are able to see and get reply from TP-link's modules.
20:39:23.634459 ARP, Request who-has 10.0.0.2 tell 10.0.0.6, length 28 20:39:23.634551 ARP, Reply 10.0.0.2 is-at 64:70:02:18:d4:6a (oui Unknown), length 28 20:39:23.636687 IP 10.0.0.6 > 10.0.0.2: ICMP echo request, id 572, seq 1, length 64 20:39:23.636809 IP 10.0.0.2 > 10.0.0.6: ICMP echo reply, id 572, seq 1, length 64 20:39:24.635497 IP 10.0.0.6 > 10.0.0.2: ICMP echo request, id 572, seq 2, length 64 20:39:24.635558 IP 10.0.0.2 > 10.0.0.6: ICMP echo reply, id 572, seq 2, length 64 20:39:28.651946 ARP, Request who-has 10.0.0.6 tell 10.0.0.2, length 28 20:39:28.654021 ARP, Reply 10.0.0.6 is-at 00:19:70:94:7c:8b (oui Unknown), length 28
My question is that what could be the reason that
10.0.0.7 cannot see the
arp-request that they send each other? How can I find out the problem?
If I add couple more nodes with ZCN wifi dongle on the network, these nodes are also not able to talk with each other, but they are fine with TP-link. Or if I swap the wifi modules, the nodes with ZCN have always problem but TP-link modules are fine.
here is the
EDIT: I was suspecting if the problem is
arp_filter related but
0 on the all subdomains(*). If I add arp info of
10.0.0.7 manually on these nodes,
wireshark does not show that they send
ping to each other. If I
ping the broadcast address (10.0.0.255 in my case),
10.0.0.7 are able hear it.
EDIT2: Here is pcap files http://filebin.net/6cle9a5iae from
10.0.0.6 (ZCN module),
10.0.0.7 (ZCN module), and
10.0.0.5 (TP-link module that does not have problem). here is the ping outputs from
10.0.0.6 http://pastebin.com/swFP2CJ9 I captured the packages simultaneously. The link also includes
uname- a outputs for each node.