[sr-dev] RTPengine iptables chain case sensitive?

[Richard Fuchs]

On 08/09/14 09:14 AM, Peter Villeneuve wrote:
> Hi,
>
> I compiled and installed deb packages as per the sipwise guide here
> https://github.com/sipwise/rtpengine. After running modprobe
> xt_MEDIAPROXY and iptables -I INPUT -p udp -j MEDIAPROXY --id 0 the new
> chain created is mediaproxy (lower case). Isn't iptables case sensitive?
> I'm not sure that it is working properly since it seems the mediaproxy
> chain (lowercase) sends all UDP packets through the MEDIAPROXY
> (uppercase) chain, which apparently didn't get created.
>
> How can I check to make sure that indeed RTPengine is relaying the
> streams properly?

I would blame whatever iptables frontend you're using there. FTR, 
"MEDIAPROXY" isn't the name of an iptables chain, it's an iptables 
target extension, same as MIRROR for example. Hence uppercase. You don't 
need to create a new chain at all.

Note however that if you use the init.d script which is included in the 
Debian package, then that will create a new chain with a lower-case name 
for you.

The best way to check which rules and chains are really created on your 
system is on the command line: 'iptables -L -v -n'

If you want to check whether kernel forwarding works as it should, watch 
the contents of '/proc/mediaproxy/0/list'. With calls active, you should 
see forwarding rules there and the packet counters increasing.

cheers