Re: NetBIOS dgm NAT Helper

[Rafa Garrido <rgarrido.l@gmail.com>]

On 9/17/05, John A. Sullivan III <jsullivan@opensourcedevel.com> wrote:
> Thank you but I don't think this helps.  It looks like it is for the
> name service rather than the datagram service.  I would think such a
> help would need to rewrite the embedded IP in the NetBIOS header and
> recalculate any checksumming - John

Sorry, have you tested this module?
http://suif.stanford.edu/~csapuntz/ip_nat_netbios.c
The only thing is that this module don't consider if it is a NetBios
package or no, assumes that if it comes from udp-port 138 is a NetBios
package.


> 
> On Sat, 2005-09-17 at 02:53 +0200, Rafa Garrido wrote:
> > It can that this patch of the last week help you:
> > http://patchwork.netfilter.org/netfilter-devel/patch.pl?id=2859
> > It will be necessary to hope to that stable kernel appears.
> > Greetings.
> >
> >
> > On 9/16/05, John A. Sullivan III <jsullivan@opensourcedevel.com> wrote:
> > > We have encountered an unusual situation where NetBIOS datagram packets
> > > (138/udp) are being passed through an IPSec tunnel on an iptables
> > > firewall but they are also being NATted by the same firewall.  It
> > > appears there is IP information embedded in the NetBIOS header.  Thus
> > > NAT causes this protocol to break because the reply packets are sent to
> > > the original IP address in the NetBIOS header rather than the NAT IP
> > > address in the IP header.
> > >
> > > I believe Cisco does have a NAT helper for NetBIOS but I have not seen
> > > anything for iptables.  Is there such a helper? Is there anyway for an
> > > iptables firewall to NAT NetBIOS datagram packets? Thanks - John
> > > --
> > > John A. Sullivan III
> > > Open Source Development Corporation
> > > +1 207-985-7880
> > > jsullivan@opensourcedevel.com
> > >
> > > If you would like to participate in the development of an open source
> > > enterprise class network security management system, please visit
> > > http://iscs.sourceforge.net
> > >
> > >
> > >
> >
> --
> John A. Sullivan III
> Open Source Development Corporation
> +1 207-985-7880
> jsullivan@opensourcedevel.com
> 
> Financially sustainable open source development
> http://www.opensourcedevel.com
> 
>