[THIN] Re: WHY

Ah, now I can ...  say you give your user a corporate laptop for working
from home - you want to allow them to browse the internet, like they do in
the office. What you *don't* want to do is allow that browsing to adversely
impact on your end device and make that that device a gateway into your
network - so *all* outbound traffic from the remote device comes through the
VPN, onto the internal network and then out again through the corporate
proxy and whatever rules and monitoring you have in place. 

 

I realise thats not as efficient as (say) allowing the user to browse
directly from their own internet connection - but it from an audit/security
point of view that configuration is easier to manage.

 

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Berny Stapleton
Sent: 30 April 2008 15:44
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: WHY

 

So why not put some other IP address space, such as if you are using 10.x
for your internal use some 192.168 or vice versa on the connections for the
CAG SSL VPN / IPSEC VPN connections and treat think of them as another
interface, as opposed to being part of the internal network. My thought
would be is that unless the traffic is coming down the TX pair from the
switch that connects to the internal interface of your firewall, and it's
addressed in those subnets, it's not internal traffic.

RE: any filters/caching/auditing/scanning that you've got set up."

Unless this is a limitation of the CAG why not just setup the scanning to do
exactly this, but from the address space of the VPN / IP SEC sessions
instead of the internal network?

I can't see the logic in bringing the traffic through the external interface
decrypting it, forcing it in across the internal interface (As that's not
where the routing table is going to send it by default) to get your scanning
and then routing it again onto the external interface.

Berny

2008/4/30 Chad Schneider (IT) <Chad.M.Schneider@xxxxxxxxxxxxx>:

"Otherwise, someone connecting on the external interface is being routed
straight out onto the web - bypassing any filters/caching/auditing/scanning
that you've got set up."

 

This is exactly my point.

 

If they connect and get an internal IP, with an internal default gateway,
all traffic to the outside, should be routed through the inside.....

 

"unless the destination address is the internal network, why SHOULD it send
it via the internal interface? "  This is also a good point.  I know this
worked fine when we had an Astaro firewall.  The thought is that the Astaro
is Linux, and Linux would note that it was an internal IP and simply send it
out the internal interface.

 

 

Chad Schneider
Systems Engineer
ThedaCare IT
920-735-7615

>>> On 4/30/2008 at 8:33 AM, <andrew.wood@xxxxxxxxxxxxxxxx> wrote:

I'd have thought that if the routing address on your internal interface was
correct,  that all traffic going through the CAG should head through the
internal interface - and then be routed out through the normal channels for
internal network traffic to the internet (which is unlikely to be the CAG)

 

Otherwise, someone connecting on the external interface is being routed
straight out onto the web - bypassing any filters/caching/auditing/scanning
that you've got set up.

 

This doesn't help Chad mind - other than agreeing with him that whats
happening sounds wrong 

 

a.

 

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Berny Stapleton
Sent: 30 April 2008 14:26
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: WHY

 

OK, maybe this is just me and my limited experience with CAG...

A VPN session which I presume is a connection from the internet (External)
to the CAG, the CAG being a gateway device between external internet and
internal network, when you bring up a VPN session, or in this case I presume
IPSEC policy between the two devices (Client PC and the CAG) which would
give you a IPSEC policy to the CAG and any traffic you send to it through
the IPSEC policy would end up on it's local routing table. At which point it
has to make a routing decision about where to send the traffic, it's an
external address so therefore it would send it to the external interface and
therefore external address.

That seems logical to me. My question to you is, unless the destination
address is the internal network, why SHOULD it send it via the internal
interface? My only educated guess on this one is that you used part of your
INTERNAL address space for the addresses you assigned to the CAG for it to
hand out to clients, when as far as I can see, the clients should have been
treated or thought of as DMZ interfaces / connections.

This is just what I am thinking about having done firewall admin before. 

If I am wrong on this one, and completley off base, please let me know, my
experiece with CAG is limited.

Berny

2008/4/30 Chad Schneider (IT) <Chad.M.Schneider@xxxxxxxxxxxxx>:

Does a VPN session to the CAG, route external bound internet traffic through
the CAG external interface, rather than through the CAG Internal interface?

 

I am watching the traffic, from our CAG internal IP range, when making a
request to google.com, the traffic goes out the CAG INT0(External).

 

 

Chad Schneider
Systems Engineer
ThedaCare IT
920-735-7615

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