I have DD-WRT running in gateway mode on a DIR-615 I1. I've updated to the newest available build.
Chromecast is a wireless-only device, for those unfamiliar. The device has been set up and operates normally using wireless devices associated with the router, but wired ethernet devices cannot communicate with Chromecast. Specifically, the Chrome plugin says "No Cast Devices Found."
AP Isolation is disabled.
I have sniffed packets between a laptop via both wired and wireless connections and Chromecast, and this is what I've found:
There are IGMP, TCP, UDP packets between Chromecast and a wireless interface on the laptop.
There are IGMP and TCP, but zero UDP packets exchanged between Chromecast and a wired ethernet interface on the same laptop.
Specifically, the wired interface does receive the following IGMP packet from the Chromecast:
1062 55.011807 192.168.1.145 126.96.36.199 IGMP 60 V2 Membership Report / Join group 188.8.131.52
... which is also observable on the wireless interface. Some packets on the wired ethernet interface are marked as having a bad ipv4 header checksum (0x0000), but I've read this is artifactual due to checksum offloading on the NIC.
Here is the (redacted) TCP stream observable on the wired interface:
GET /ssdp/device-desc.xml HTTP/1.1 Host: 192.168.1.145:8008 Connection: keep-alive Cache-Control: max-age=0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.49 Safari/537.36 DNT: 1 Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8,fr;q=0.6 HTTP/1.1 200 OK Application-URL: http://192.168.1.145:8008/apps/ Content-Type: application/xml Content-Length: 1078 <?xml version="1.0"?> <root xmlns="urn:schemas-upnp-org:device-1-0"> <specVersion> <major>1</major> <minor>0</minor> </specVersion> <URLBase>http://192.168.1.145:8008</URLBase> <device> <deviceType>urn:dial-multiscreen-org:device:dial:1</deviceType> <friendlyName>Bedroom TV</friendlyName> <manufacturer>Google Inc.</manufacturer> <modelName>Eureka Dongle</modelName> <UDN>uuid:XXXXXXXXXXXXXXXXXXXXXXXXXXXXX</UDN> <iconList> <icon> <mimetype>image/png</mimetype> <width>98</width> <height>55</height> <depth>32</depth> <url>/setup/icon.png</url> </icon> </iconList> <serviceList> <service> <serviceType>urn:dial-multiscreen-org:service:dial:1</serviceType> <serviceId>urn:dial-multiscreen-org:serviceId:dial</serviceId> <controlURL>/ssdp/notfound</controlURL> <eventSubURL>/ssdp/notfound</eventSubURL> <SCPDURL>/ssdp/notfound</SCPDURL> </service> </serviceList> </device> </root>
This is apparently not good enough for function, and the lack of UDP packets going in the ath0 --> eth1 (the WLAN and LAN interfaces on the DD-WRT router) direction is suspicious. Can anyone shed light on what may be happening? Bridge and route settings on the DD-WRT are all basically default.