Firewall (iptables) issues?

[Eric Norum <wenorum@lbl.gov>]

Apologies if this is a FAQ.  I'm new to the intricacies of Linux firewalls.

I'm trying to get a linux system
Linux xildev2 2.6.18-194.11.3.el5.lbl1 #1 SMP Thu Sep 16 14:50:58 PDT 2010 x86_64 x86_64 x86_64 GNU/Linux
to work as a channel access client.

If I use EPICS_CA_ADDR_LIST to explicitly provide the address of my IOC things work fine.   If I leave EPICS_CA_ADDR_LIST undefined my client applications see no PVs.

I poked holes in the firewall for the channel-access ports:
iptables -L
.
.
ACCEPT     udp  --  anywhere             anywhere            udp dpt:ca-1 
ACCEPT     udp  --  anywhere             anywhere            udp dpt:ca-2 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ca-1 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ca-2 
.
.
but that didn't seem to make any difference.
I restarted caRepeater after making the firewall changes.  Still no PVs.

Suggestions?
-- 
Eric Norum
wenorum@lbl.gov