On Apr 21, 2012, Richard Thornton wrote:

> Hi,
> 
> I am not sure if this is possible and would be grateful for the advice.  I
> want to avoid using VPNs as the resources are not super sensitive.
> 
> I have an Ubuntu box with multiple interfaces including pppoe adsl2 and I
> am going to use it as a firewall.
> 
> I have 8 servers with private IPs that I need access to and I have 9 public
> IPs (one IP is firewall external interface).
> 
> I would like fwknop to give me access to the servers (and also to control
> ssh access to the firewall).
> 
> The servers will mostly have ssh and https but there is also rdp and esxi
> mgmt ports on some.  I am happy with the security implications of extending
> the rule duration to make http work better.
> 
> So can fwknop handle creating the 8 DNATs and corresponding 8 SNATs so each
> server can be accessed 1:1 with the public IPs?

Yes, I believe that the either the regular DNAT mode or the FORCE_NAT mode
will support this.  A corresponding SNAT rule can be created too, but is
usually only necessary if the internal systems don't have a route back out.

On the client side, here is an example invocation for SSH access:

$ fwknop -A tcp/22 -a <clientIP> -D <serverExternalIP> -N <internalIP>:22

If you use the FORCE_NAT mode on the server, you don't in the "-N ..." stuff
on the client side - the incoming connection to the requested service will
be NAT'd transparently by the server and the client will never know it.

On the server side, make sure to set:

ENABLE_IPT_FORWARDING       Y;

If you need SNAT support at the same time (not likely in most situations)
then set:

ENABLE_IPT_SNAT             Y;

Now, if you are using the FORCE_NAT mode, then for each internal service
create a different stanza in the access.conf file and use the FORCE_NAT
directive.  Here is an example where "192.168.1.123" is an IP of one of the
internal systems:

SOURCE: ANY;
KEY: somefwknopkey;
FW_ACCESS_TIMEOUT:  30;
FORCE_NAT: 192.168.1.123 22;

Thanks,

--Mike



> Any tips, tricks or advice would be much appreciated.
> 
> Thanks for looking.
> 
> Cheers
> Richard

> ------------------------------------------------------------------------------
> For Developers, A Lot Can Happen In A Second.
> Boundary is the first to Know...and Tell You.
> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
> http://p.sf.net/sfu/Boundary-d2dvs2

> _______________________________________________
> Fwknop-discuss mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/fwknop-discuss


------------------------------------------------------------------------------
For Developers, A Lot Can Happen In A Second.
Boundary is the first to Know...and Tell You.
Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
http://p.sf.net/sfu/Boundary-d2dvs2
_______________________________________________
Fwknop-discuss mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/fwknop-discuss

Reply via email to