Modify

Opened 5 years ago

Last modified 4 years ago

#13151 reopened defect

multicast packets are dropped

Reported by: rsctm@… Owned by: developers
Priority: normal Milestone: Barrier Breaker 14.07
Component: kernel Version: Trunk
Keywords: Cc:

Description

I've got OpenWrt trunk r35673 on a TP-Link WR842ND, which I am trying to use to share the HDD via DLNA to the TV.

After ~10 minutes MiniDLNA always "disappears" and is not discovered by the TV until I manually restart the MiniDLNA service.

To track down this issue, I've compiled a simple SSDP tool, which joins the dlna multicast group and answers M-SEARCH packets and of course dumps the the traffic to the console.
It has the same issue as MiniDLNA, the TV discovers the content directory, it works very well for like 10 minutes, then it disappaers AND the application does not receive any multicast packets anymore. When i restart the process, everything works well again.
When I also run tcpdump -n -i br-lan -X udp while investigating this problem, it does NOT happen. (My app keeps receiving the multicast packets)

I dont know if it matters, the TV has wired connection to router, dmesg has lines like this:

[154767.440000] eth0: link up (1000Mbps/Full duplex)
[154767.440000] br-lan: port 1(eth0) entered forwarding state
[154767.450000] br-lan: port 1(eth0) entered forwarding state
[154769.450000] br-lan: port 1(eth0) entered forwarding state
[197332.670000] eth0: link down
[197332.670000] br-lan: port 1(eth0) entered disabled state
[222579.270000] eth0: link up (1000Mbps/Full duplex)
[222579.270000] br-lan: port 1(eth0) entered forwarding state
[222579.280000] br-lan: port 1(eth0) entered forwarding state
[222581.280000] br-lan: port 1(eth0) entered forwarding state

Attachments (0)

Change History (12)

comment:1 Changed 5 years ago by jogo

Is this a snapshot image or a self compiled image? If the latter, did you by chance enable multicast snooping in the kernel?

comment:2 Changed 5 years ago by anonymous

It is a snapshot image. Firewall is default as well. No dropped/rejected counters increase.

The strange is: as I mentioned, my app stops receiving the packets after a while (~5 mins). If I dont restart it but start a tcpdump session in a new ssh window, my app receives the M-SEARCH stuffs again. And as soon as I stop tcpdump, my app wont get anything again.

At first I thought its somehow connected with the bridge, when the TV is turned on the bridge is reinitalized and multicast gets broken. But it is NOT the case, its happening also when there is no eth event.

Now I believe the kernel "forgets" the IP multicast group membership subscriptions for some reason.

comment:3 Changed 5 years ago by ryrzy85

i would like to say that in AA RC1 dlna servers work perfect, and did't disappear from network... maybe this will help in fixing it

comment:4 Changed 5 years ago by anonymous

jogo, please read this topic, i am quite sure its connected:

https://forum.openwrt.org/viewtopic.php?pid=195397

comment:5 Changed 5 years ago by raf.szczesny@…

Hi,
Another thing. What about multicast over vpn (using racoon)? I'm asking because when I'm connected to router over VPN I don't see minidlna.

comment:6 Changed 5 years ago by anonymous

anothee thing... when in network is other dlna server like allshare on pc it is vissable ony few minutes like minidlna on openwrt server... on aa is ok.... please find a solution for this problem :(

comment:7 Changed 5 years ago by raf.szczesny@…

Hi,
Problem with vpn is not related to this issue. Racoon with Ipsec doesn't propagate the packets.

comment:8 Changed 4 years ago by nbd

please test if it works again in latest trunk.

comment:9 Changed 4 years ago by nbd

  • Resolution set to no_response
  • Status changed from new to closed

comment:10 Changed 4 years ago by djdeeles@…

  • Resolution no_response deleted
  • Status changed from closed to reopened

i have similar problem with r41777.
Minidlna does not appear in tv or dissapear after some time

comment:11 Changed 4 years ago by nbd

should be fixed in r41818, please test.
you need to clean the kernel tree after updating.

comment:12 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

Add Comment

Modify Ticket

Action
as reopened .
Author


E-mail address and user name can be saved in the Preferences.

 
Note: See TracTickets for help on using tickets.