LAN Incompatibility?

[tsimon]

Background:
I Currently have two mt-daapd servers running. One is an old dell 2300 with a standard 10/100 NIC card. The standard mt-daapd install from the Feisty repository worked great. In an effort to curb my power consumption I picked up one of those little Jetway mini-itx boards with an integrated Dual Realtek LAN chip 10/100/1000 (RTL8110SC).

I repeated this same install process that worked before without success. I believe the problem is related to the chip dropping multicast packets. I’ve tried several solutions listed in the forums including: putting the card into promisc mode, clearing out iptables and changing the default policy to accept, installing different nightly builds, and recompiling the the LAN driver from the source found on realtek’s site (which made everything worse).

Problem:
The most common problem I’ve had (with the new jetway mobo) is iTunes cannot find the mt-daapd server after you close and reopen the application. If you restart the mt-daapd server with iTunes open everything works great. The mt-daapd server will still be listed in the iTunes share after 30 minutes has passed (strange).

Last note:
I read about one guy who had to install a network bridge of some sorts. Could anyone give me some more insight into this? Could it work?

Thank you,
Trent.

[rpedde]

@tsimon wrote:

Background:
I Currently have two mt-daapd servers running. One is an old dell 2300 with a standard 10/100 NIC card. The standard mt-daapd install from the Feisty repository worked great. In an effort to curb my power consumption I picked up one of those little Jetway mini-itx boards with an integrated Dual Realtek LAN chip 10/100/1000 (RTL8110SC).

I repeated this same install process that worked before without success. I believe the problem is related to the chip dropping multicast packets. I’ve tried several solutions listed in the forums including: putting the card into promisc mode, clearing out iptables and changing the default policy to accept, installing different nightly builds, and recompiling the the LAN driver from the source found on realtek’s site (which made everything worse).

Problem:
The most common problem I’ve had (with the new jetway mobo) is iTunes cannot find the mt-daapd server after you close and reopen the application. If you restart the mt-daapd server with iTunes open everything works great. The mt-daapd server will still be listed in the iTunes share after 30 minutes has passed (strange).

Last note:
I read about one guy who had to install a network bridge of some sorts. Could anyone give me some more insight into this? Could it work?

Thank you,
Trent.

Are you sure you turned off the firewall? that sure sounds like the server isn’t seeing inbound multicast packets.

You can test it, I guess… you can run tcpdump on the interface and open iTunes and see if you can see multicasts to udp port 5353 from 224.0.0.251.

[tsimon]

Mt-daapd works great under the following conditions:
I open iTunes on the client,
on the mt-daapd server I type: tcpdump port 5353
I wait a minute or so, and the share pops up in iTunes.
I can repeatedly close and open iTunes with the share appearing immediately, (just like my old Dell).

…however…
if I start running tcpdump with itunes closed, my little firefly server is never discovered, the old dell is though.
I also need to run tcpdump on port 5353, specifically.

Iptables is also free any rules with the default policy set to accept.

Thank you,
Trent

[tsimon]

It now appears to be completely random with regard to when server will respond to the multicast packets and when it won’t. But, it works great with an old usb nic I found.

[rpedde]

@tsimon wrote:

It now appears to be completely random with regard to when server will respond to the multicast packets and when it won’t. But, it works great with an old usb nic I found.

Definitely an issue with the nic not seeing the multicast packets. The clue there is when tcp dump shifts the box into promiscuous mode it works.

Also, the randomness is probably because when the server first start, it gratuitously pre-caches mdns info for about ten minutes or so.

So when you start it, even if it can’t see queries, the queries get answered and it populates iTunes browses because of the gratuitous mdns pre-caching.

Well, and the “other nic works” thing is kind of a dead giveaway too.

— Ron

[tsimon]

thank you for the breakdown, does this mean I can’t use the integrated LAN?

[rpedde]

@tsimon wrote:

thank you for the breakdown, does this mean I can’t use the integrated LAN?

I think it points to multicast issues on the driver. And you are sure that “ifconfig eth0 promisc” doesn’t fix it?

The only other thing I could think is newer kernel. I had to update to 2.6.22.6 to get WoL working right on my rtl, so I think the realteks are a work in progress.

— Ron

[tsimon]

I tried:

# ifconfig eth0 promisc

where eth0 is my device and that didn’t work. I put in another reltek 10/100/1000 pci (8139c) card and everything is working well. I’m hesitant to upgrade the kernel now that everything is working.

thank you for your time,
trent

[rpedde]

@tsimon wrote:

I tried:

# ifconfig eth0 promisc

where eth0 is my device and that didn’t work. I put in another reltek 10/100/1000 pci (8139c) card and everything is working well. I’m hesitant to upgrade the kernel now that everything is working.

thank you for your time,
trent

I’d guess at some point on an upgrade it will probably start working, but I’m with you — if it’s working now, probably not much point in worrying about it.

— Ron

[Author]

Posts