port blocking? oracle problem? Other?

[john abbott <john_(_dot_)_abbott_(_at_)_pca_(_dot_)_state_(_dot_)_mn_(_dot_)_us>]

OK, here is the deal, I had one firewall, HP Vectra XU 150 Pent. Pro
running openbsd 2.8 and ipf.   Behind it I had four web servers and an
oracle server.  Everything was running great.  

But, because of some other software that was running on the oracle
server, it seemed like a really great idea to move the oracle server and
setup firewall #2, also a HP Vectra XU with only the oracle server
behind it.  Troubles.  

The web servers behind firewall #1 and are making queries (and replies?)
via port 1521 to the oracle server and everything is working great. 
...for a few hours.  Then something happens, and I don't know quite
what, but suddenly port 53 and 1521 starts being blocked.

Nov 29 12:50:39 webwall ipmon[7936]: 12:50:38.533470             fxp0
@0:58 b 156.92.18.90,53 -> 156.92.18.150,10007 PR udp len 20 150  IN
Nov 29 12:50:54 webwall ipmon[7936]: 12:50:53.648449             fxp0
@0:58 b 156.92.215.252,1521 -> 156.92.18.150,10008 PR tcp len 20 44 -AS
IN

(yeah, ok, I need to set the date on my firewall :-) The web servers can
no longer find the oracle servers and 1521 is getting blocked too. 
Other stuff continues to work just fine, port 80 keeps getting passed
just fine, I can still ssh into the machines just fine.  

I guess my questions are, what could be causing this?  Why would it only
be causing trouble with just these ports?   Are the firewalls getting
overloaded or something and is that what causes these ports to become
blocked?

--ja
-- 
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  John Abbott 
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  Minnesota Pollution Control Agency
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