On Thursday 23 May 2002 8:40 pm, Marc Aurele La France wrote:

> Globus, a grid computing package, relies on an aspect of UDP that is
> seldom used.  Specifically, a reply can come from anywhere on the planet,
> not just from the destination of the prompting packet.

Why should UDP allow a packet from machine A to machine B to be replied with 
a packet from machine C ?   I don't understand the sense in this....

You seem to be suggesting that de-masquerading might be done based solely on 
the destination address/port of the replying packet.

eg a packet is sent from address A, port a, to address B, port b.   Normally 
you'd expect to see a reply from Bb back to Aa, but you're suggesting that a 
reply from Cc to Aa should be de-masqueraded and allowed in through the 
firewall ?

Sounds to me like:

a) a pretty strange request
b) a potentially big security hole
c) a fairly easy thing to implement as a patch to existing code (because 
you're removing a check which is already there - simpler than adding 
something new)

However, I'm not the person to create that patch :-(

Maybe you should either try asking the netfilter developers' list, or look 
through patch-o-matic and see who has produced a patch closest to what you 
need, and ask if they're able to do another one for you ?

Best of luck with the request, and I'm fascinated to know why this is 
considered a sensible way to run UDP....



Antony.

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