Re: Forwarding RealAudio thru 2.2.19 firewall?

["Paul Tod Rieger" <prie@abl.com>]

"Scott Bigham" <dsb@killerbunnies.org> wrote:

> Are there known issues with forwarding/masquerading RealAudio
> connections through a 2.2.19 kernel?  I upgraded my firewall box from
> 2.2.17 to 2.2.19 not long ago, and later noticed that machines on the
> LAN were unable to connect to RealAudio servers.  Once I realized that
> the two happened at around the same time, I rebooted back into 2.2.17
> to check, and it started working again.

Using RealPlayer 6 on w98 behind a 2.2.19/ipmasq server, I am able to
connect to a RealServer 6.


> The two kernels are configured essentially the same; the only net-related
> differences I can find are that in the 2.2.19 kernel, IPv6 is included
> (as a module, which doesn't show up in lsmod) and IP-over-IP tunneling is
> built-in instead of a module.

I think I have both those turned off:

# fgrep IP kernel-image-2.2.19pre17_custom.1.0_i386.config
CONFIG_IP_FIREWALL=y
CONFIG_IP_MASQUERADE=y
CONFIG_IP_MASQUERADE_ICMP=y
(all other CONFIG_IP_* not set)


>  I even went so far as to put a -l on the ipchains ACCEPT rules
> for UDP ports 6970:7170, and AFAICT no packets are even
> coming in on those ports during a RealAudio connection attempt.

Real's original PNA approach used 7070.  The more recent RTSP uses 554 (tcp
and udp).  The newest may use something else.  You're more than welcome to
try my RealServer 6:

http://calypso.abl.com:8080/ramgen/live.smil

which should negotiate a RTSP connection with your RealPlayer 6.0 and above,
or try RTSP directly (File-->Open Location):

rtsp://calypso.abl.com/encoder/live.rm

Tod
abl.com