Linux Help
guides forums blogs
Home Desktops Distributions ISO Images Logos Newbies Reviews Software Support & Resources Linuxhelp Wiki

Welcome Guest ( Log In | Register )

Advanced DNS Management
New ZoneEdit. New Managment.


Sign Up Now
Reply to this topicStart new topic
> Help - Multicast Packet Forwarding
post Jan 26 2005, 01:32 PM
Post #1

Whats this Lie-nix Thing?

Group: Members
Posts: 1
Joined: 26-January 05
Member No.: 4,588

I have a linux box - Fedora Core 2 with kernel 2.6.5 - acting as a bluetooth access point. The interface it uses for bluetooth is pan0 with ip address The access point is connected to a wired LAN over interface eth0 which has IP address 192.168.1.x, which it gets from a DHCP server running on the LAN. I am running UPnP devices on several other hosts on the LAN, each with IP address 192.168.1.x.

I have several cell phones connected to the access point over bluetooth. Each phone has a static ip address 192.168.70.x. I have enabled ip forwarding on the access point and the phones are able to ping any host on the wired LAN. The phones all run control point applications that allow them to control the UPnP devices on the LAN.

The problem is that during the discovery phase, the control point issues a multicast MSEARCH message. UPnP issues multicasts on with netmask These packets are not getting forwarded by the access point. I have tethereal listening on eth0 and the packets never get sent out. So the phones are unable to discover devices on the wired LAN. I also want the phones to receive incoming multicasts from the devices on the LAN. The UPnP devices use mulitcast to send event updates to control points that are subscribed to the events. I need the phones to receive these events.

So I need the multicast to go from pan0 to eth0 and the reverse, which is where I am having trouble. Putting in two new entries into the routing table like this won't work:
route add -net netmask eth0
route add -net netmask pan0

This doesn't work because route will just follow the first match that it sees and so all the multicast packets will just be echoed onto eth0.

I thought about using a bridge, but I haven't tried it out yet. I am already implicitly using a bridge with the Bluez bluetooth stack since each new phone connection creates a bnepX interface which is automatically added to the pan0 bridge. I had problems briding earlier with the eth0 interface. Right now I also already have everything set up using ip forwarding so I am wondering if anyone has a solution to this using iptables or route. I would appreciate some help on this. Thanks.
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 23rd June 2018 - 01:45 AM