1 Topic by vincentfox (edited by vincentfox 2008-12-14 08:39:40)

  • Registered: 2008-12-11
  • Posts: 1

Topic: DUP packets?

I am running Chilli 1.1.0 on OpenWRT Kamikaze r13624 at present.
It works fine for Windows users but not Macintosh.  Mac users cannot
even get the login page.  If I test from Mac it shows DUP packets
on every ping.  I connected laptops via wired LAN ports to eliminate
WiFi issues and the problem persists.

When I run tcpdump on WRT I can clearly see the dups:

23:27:15.723230 IP 10.69.2.1 > 10.69.2.2: ICMP echo reply, id 512, seq 1536, length 40
23:27:15.820406 IP 10.69.2.2 > 10.69.2.1: ICMP echo request, id 512, seq 1536, length 40
23:27:15.821217 IP 10.69.2.1 > 10.69.2.2: ICMP echo reply, id 512, seq 1536, length 40

Perhaps Windows is forgiving of these duplicates & Mac is not?
How can I separate where these dups are introduced?
My prime suspects would be kmod-tun or chilli, others?

  • Registered: 2009-04-14
  • Posts: 3

Re: DUP packets?

Hi guys,
I have the same issue on openwrt with macintosh and linux clients. I will check that on debian, but i guess is something wrong with last release of openwrt, because I use chillispot on it from two years ago and this issue is new.

Yea... windows ignore the dup message so look like work well, but go more slowlly.
My suspect is arround firewall or routing... but I do not discard anything.

I did think some issue with dnsmasq because dhcp can go to chilli interface, but i did stop it and do not solve the problem.

ok guys i will do more test and if i find the cause i will tell

  • Registered: 2008-03-14
  • Posts: 7

Re: DUP packets?

Old topic, but I have a solution.

Basically, the tun0 interface is brought up on another interface (say, wlan0). without proper firewall rules, packets can travel back along both interfaces to the client.

Solution, do not allow traffic on the offending interface (in this case wlan0). No more DUPs.