Apple TV works wired but doesn't work with Airport

Question

Hello everybody
I have the following:
o Mac Book Pro 13
o Apple TV
o D-Link WiFi Access Point (192.168.1.0/24)
o Ethernet Network (also 192.168.1.0/24)
o DHCP Server
Initially I connected to Apple TV via Ethernet. As long as my Mac Book is wired to the network (firewall disabled, 192.168.1.189), Apple TV (also wired via Ethernet, 192.168.1.182) is able to connect to my iTunes library and iTunes finds Apple TV and everything works just fine. However, as soon as I connect my Mac Book via WiFi (192.168.1.200), the connection between these two devices is lost.
As a network administrator this confuses me quite a lot. I thought, that the communication between these two softwares is a typical client server connection using daap protocol. For me it would be logical that iTunes connects to Apple TV on startup and establishes the network connection. Obviously I am wrong!
What do I have to do, to make these two devices communicating while my Mac Book is wired as well as WiFi'ed to my private network? Any help is appreciated.
So long, Stefan

Answer 1

OK, I tcpdump'ed the network traffic on the wifi network adapter while opening iTunes. There are many mdns (bonjour) packets, even from the Apple TV box. That most probably means, that the two devices are being found using bonjour. The Apple TV box also sends the following request to my iTunes:
+GET /ript/readytoconnect?machine-id=0x2D19D2D21EE788ED HTTP/1.1+
+Host: 192.168.1.200:3689+
+User-Agent: iTunes-AppleTV/4.1 (2)+
+Accept-Encoding: gzip+
+Connection: close+
+HTTP/1.1 204 No Content+
+Date: Tue, 30 Nov 2010 19:29:54 GMT+
+DAAP-Server: iTunes/10.1 (Mac OS X)+
+Content-Type: application/x-dmap-tagged+
+Content-Length: 0+
As long as my Mac Book Pro is ethernet wired, the request from the Apple TV box looks quite different:
+POST /ript/readyforconnect HTTP/1.1+
+Host: 192.168.1.182:3689+
+User-Agent: iTunes/10.1 (Macintosh; Intel Mac OS X 10.6.5) AppleWebKit/533.19.4+
+Accept-Encoding: gzip+
+Content-Length: 453+
+Connection: close+
+<?xml version="1.0" encoding="UTF-8"?>+
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">+
+<plist version="1.0">+
<dict>
<key>homeShareGroup</key>
<string>00000000-1114-3a7c-f441-ca08dbf24097</string>
<key>iTunesDatabaseID</key>
<integer>7401468360494643499</integer>
<key>iTunesMachineID</key>
<integer>4142801218510725739</integer>
<key>pairingGUID</key>
<integer>0</integer>
</dict>
</plist>
+HTTP/1.1 200 OK+
+Date: Tue, 30 Nov 2010 16:11:28 GMT+
+RIPT-Server: iTunesLib/4.1 (Mac OS X)+
+Content-Type: application/octet-stream+
+Content-Length: 214+
+Content-Encoding: gzip+
Any help with bonjour and Airplay is appreciated.
Thanks...