On 19 Dec 2001 at 3:13, [EMAIL PROTECTED] wrote:

>   It seems to me that running out of log space *should* not be a 
> normal condition, and might indicate a deliberate hostile attempt to 
> disable logging.  Whether one wants to continue to permit connections 
> with logging disabled is a policy decision that might very well go 
> either way, although I'd expect those who'd prefer TCP to UDP for 
> syslog would tend to incline to the more defensive option.

In our case it was due to the machine used for syslog having not enough 
space. It also caused the PIX to stop when it crashed - if you use TCP for 
syslogging on the PIX make sure your syslog server is very robust!
 
>   In a perfect universe, the choice of whether to continue permitting 
> traffic when logging is known to have failed could be a separate 
> option, orthogonal to whether one choses to use a connection-based 
> protocol for logs (although the choice cannot meaningfully be made 
> with a connectionless protocol...).
>   But, short of such perfection, I think this is quite likely to be a 
> deliberate and defensible design decision by Cisco, rather than a 
> known bug, defect, or oversight.

I understand why Cisco has included this feature - in some circumstances 
it is desirable to prevent access to your network if your are unable to 
record what is happening. My earlier reply was really to say that you 
should think carefully about using TCP for syslog on the PIX as there as 
some risks involved - for instance, if you're running an e-commerce site 
that relies on the web server being accessible 24/7 then you might not 
want connections to be stopped when the syslog server has a problem, 
you're willing to risk not recording logs in order to allow your customers 
to continue buying your products. Blindly using TCP syslogging without 
consideration could render your public services unreachable in the event 
of a problem with the syslog server which becomes a single point of 
failure in the system.

Dan
---
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