Surely I have anti-spoofing active.
This is kinda similar to what I'm experiencing :

IF      Service         Source          Target          SrcPort

eth1    6002                    192.168.0.100   172.24.0.100    10023
eth3    12345                   172.24.0.100    192.168.0.100   6002 

The first case it's ok. I have 172.24.0.100 connected to the proper firewall
interface (let's say eth3) listening on TCP 6002 (this is a range of
registry fixed port, being it a micro$oft RPC). The source port is a high
random assigned port.

The second case, is what I'm not expecting: it's the same kind of
connection, but FW1 sees it "inverted", the IF is changed, but I think it
won't be appropriate to consider it address spoofing. Nevertheless I'm not
expecting this behaviour... When stateful inspection is applied, connections
on the second case are dropped, seen as out of state.

Now I'll make the test you're suggesting...

Lorenzo

-----Messaggio originale-----
Da: Mailing list for discussion of Firewall-1
[mailto:[EMAIL PROTECTED] Per conto di Charalambos
Klitiropoulos
Inviato: giovedì 28 luglio 2005 22.20
A: [email protected]
Oggetto: Re: [FW-1] R: [FW-1] R: [FW-1] Inverted Connections

Hello,

now you got me confused. Given that VRRP is an active-standby mechanism,
then under normal circumstances only one cluster member should be active at
any given time. With this in mind, if packets for server A come out of your
firewall from interface X and its replies go through interface Z, then the
error should be about spoofed packets, provided you have enabled
anti-spoofing checking.

If the error is about out of state packets - and the error is generated by
other than the active cluster member, then you should check your cluster. 
You can do that with commands "fw cpl pstat" and "fw tab -t connections -s".

The first one provides information about FW-1's synch mechanism and under
normal operation you should see that the total number of sync packets is non
zero and increasing. The second one gives you information about the number
of connections the firewall knows of and under normal operation the values
must be close in each cluster member. You can find more information about
these commands in Check Point's KB.


On 7/28/05, Lorenzo <[EMAIL PROTECTED]> wrote:
> 
> Yep I know, the actual configuration is really absurd (I mean I'm 
> paying lotsa money to have kinda kernel 2.2 linux firewall)... This 
> is, as you guessued, a big installation and, yes, there's an async 
> routing (I mean the "returning" connections pass thru a different 
> interface). In your opinion, how can I check if the syncronozation is 
> working correctly ?(I'm using Nokia with VRRP and, as far as I know, 
> the nodes switch correctly from one to another. CP is configured with 
> VRRP and there's a syncro net with a heartbeat interface. The only 
> difference in my config with Nokia's suggested one is that the two IP 
> appliances are linked via a crossed cable instead of a switch).
> 
> Thanx in advance
> 
> Lorenzo
> 
> -----Messaggio originale-----
> Da: Mailing list for discussion of Firewall-1 
> [mailto:[EMAIL PROTECTED] Per conto di 
> Charalambos Klitiropoulos
> Inviato: martedì 26 luglio 2005 23.54
> A: [email protected]
> Oggetto: Re: [FW-1] R: [FW-1] Inverted Connections
> 
> Disabling stateful inspection will convert a (expensive) stateful 
> firewall into a plain packet filtering firewall. Could there be a case 
> of asynchronous routing (where incoming packets take a different route 
> than outgoing)? Maybe a high availability configuration with 
> non-working synchronization? Please note that I have seen drops like 
> that in the past (confirmed without asynchronous routing), but every 
> case was in a large installation and the percentage of dropped 
> connections was far too low to be a real problem for the users.
> 
> On 7/26/05, Lorenzo <[EMAIL PROTECTED]> wrote:
> >
> > Yes. It's seen as out of state... Obviously if I disable the check 
> > on stateful TCP packets the connection works...
> >
> > -----Messaggio originale-----
> > Da: Mailing list for discussion of Firewall-1 
> > [mailto:[EMAIL PROTECTED] Per conto di 
> > Charalambos Klitiropoulos
> > Inviato: lunedì 25 luglio 2005 21.31
> > A: [email protected]
> > Oggetto: Re: [FW-1] Inverted Connections
> >
> > Hello,
> >
> > is there any information in the information column? There can be 
> > cases where
> > FW-1 will drop a connection because of an invalid TCP packet or 
> > because of a SmartDefense setting. Even if that connection was 
> > originated by HOST1, but
> > SERVER1 sent a packet that FW-1 does not consider to be correct, the 
> > drop log entry will show that source was SERVER1 and destination was 
> > HOST1. But in every such case you should see some comment in the 
> > information column that explains why FW-1 dropped that packet.
> >
> > On 7/25/05, Lorenzo <[EMAIL PROTECTED]> wrote:
> > >
> > > Hi guys
> > > Does anybody has had the same problem ?
> > > Basically, I'm exptecting a connection from HOST1 to SERVER1 on 
> > > TCP port, let's say, 6000. This happens, but sometimes I see on 
> > > the tracker that there are some connections from SERVER1 to HOST1, 
> > > with a "random" destination port and 6000 as source port.
> > >
> > > I'm wandering if this could be a CheckPoint problem....
> > >
> > > Thanx in advance
> > >
> > > Lorenzo
> > >
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