Re: [squid-users] Checkpoint FW1 & Securemote client

From: Wei Keong <chooweikeong@dont-contact.us>
Date: Fri, 31 May 2002 11:49:27 +0800

Hi All,

Thanks for all your reply...

> Ward:
> secureremote creates a tunnel to the firewall .. its more likely that the
firewall is not allowing him access.

The user is able to use telnet, ftp through Securemote. He should have no
problem connect to the Checkpoint firewall. Moreover, the reply is not
'authentication failed' but 'page cannot display'.

> Bill:
> I would say to not send your dedicated server HTTP requests through the
> proxy server. Maybe put the entire encryption domain in your browsers
bypass
> proxy list. SecuRemote is using VPN and IPSec to establish a secure route
> between your computer and the firewall. When you try to put Squid in
> between, you're breaking that route. SecuRemote is going to 'encapsulate'
> everything going to an address in the encryption domain, not just HTTP
> requests. We use telnet, ftp,x-windows,Windows Terminal Server over VPN
> SecuRemote clients.

The problem is the transparent proxy will 'hijack' all port 80 traffic and
redirect to the Squid box. Seems that with TP will not work in this case...

> Neil:
> In theory, if it's going through a proxy the firewall will see the address
> of the proxy, not that of the client.

If the authentication packet is sent through port 80, it will be hijacked by
Squid. The firewall will see the Squid IP and assume that the Squid box
trying to authenticate.

If the authentication packet is not sent through port 80, it will no be
hijacked by Squid. The firewall will be able to authenticate the user.
However, the http request from the browser will be encrypted and Squid will
not be able to understand the request... am i right?

> Neil:
> Switching to ISAKMP/OAKLEY should help although I'm
> waiting to have it confirmed.

Will this work? how to enable this?

Rgds,
Wei Keong

----- Original Message -----
From: "Neil A. Hillard" <hillardn@whl.co.uk>
To: "Wei Keong" <chooweikeong@pacific.net.sg>
Cc: "Squid Users" <squid-users@squid-cache.org>
Sent: Thursday, May 30, 2002 11:11 PM
Subject: Re: [squid-users] Checkpoint FW1 & Securemote client

> Wei,
>
> > Thanks for your reply.
> No probs.
>
> > Frankly I'm not very familiar with Securemote... This is how the network
> > layout looks like
> >
> > Securemote client --> Our (ISP) proxy --> Checkpoint FW1
> In theory, if it's going through a proxy the firewall will see the address
> of the proxy, not that of the client.
>
> SecuRemote works as follows:
>
> 1) Client requests network topology from remote firewall (this is when you
> add the firewall in to SecuRemote). The topology describes what networks
> are behind the firewall. (this happens on TCP port 256 or 264 dependant
> on SecuRemote version)
>
> 2) When SecuRemote sees a packet destined for a network behind the remote
> firewall it establishes an encrypted session to the firewall and then
> authentication takes place (be it reusable password SecurID, Radius, etc.)
> (this authentication is encrypted)
>
> 3) Once authenticated all traffic is encrypted down the tunnel.
>
> Notes:
>
> o as someone else has just pointed out it's worth checking that the
> rules on the firewall allow access to the desired service although
> authentication should take place before the rulebase is consulted.
>
> o Check in the firewall log viewer and ensure that the IP address that the
> firewall sees is the SecuRemote client and not the proxy's
>
> o Check the log viewer to see if the request is being dropped
>
> Anyway, hope some of this helps.
>
>
> Neil.
>
> > Let me explain the senario in greater details...
> >
> > The user has an securemote client pointing the the Checkpoint FW1. With
the
> > client running, when the user try to access a dedicated server through
http
> > (http://x.x.x.x), the Checkpoint login prompt will not appear. If the
user
> > try port 900 (http://x.x.x.x:900) the prompt will appear. However, even
> > after authentication, the user could not get any page reply.
> >
> > As far as I understand, there shouldn't be any NAT between the client
and
> > the firewall. Most likely, the NAT is done at the firewall itself. One
> > possible explaination could be that after the user successfully login to
CP,
> > the browser request will be forwarding by Squid to the CP. Not aware of
the
> > presence of Squid, CP will then reply an encrypted http page to the
client.
> > When Squid see an encrypte reply, it will not understand and forward it
back
> > to the browser.
> >
> > Please enlighten me...
> >
> > Rgds,
> > Wei Keong
> >
> >
> >
> > ----- Original Message -----
> > From: "Neil A. Hillard" <hillardn@whl.co.uk>
> > To: "Wei Keong" <chooweikeong@pacific.net.sg>
> > Cc: "Squid Users" <squid-users@squid-cache.org>
> > Sent: Thursday, May 30, 2002 9:49 PM
> > Subject: Re: [squid-users] Checkpoint FW1 & Securemote client
> >
> >
> > > Wei,
> > >
> > > > We have this user whose Securemote client could not authenticate and
> > access
> > > > his intranet webpages through Checkpoint FW. We suspect that our
> > transparent
> > > > proxy might have caused this problem.
> > > Not sure that this is entirely on-topic, but here goes anyway...
> > >
> > > > After some debugging, the user is managed to authenticate by using
port
> > 900
> > > > (http://x.x.x.x:900/). But, he still could not access his intranet
> > webpages.
> > > > Have you encountered similar problem? Besides removing the user from
> > > > transparent proxy, is there anything we can do to resolve this?
> > > Can you indicate the layout of the network that the user is connecting
> > > over so I can see if your problem is the same as the one I'm
experiencing.
> > >
> > > You don't happen to be using FWZ Client Encryption and the client is
also
> > > going through some NAT or masquerading device ??? If so that may very
> > > well be the cause. Switching to ISAKMP/OAKLEY should help although
I'm
> > > waiting to have it confirmed.
> > >
> > > Have a look at www.phoneboy.com for similar problems...
> > >
> > > HTH,
> > >
> > >
> > > Neil.
> > >
> > > --
> > > Neil Hillard hillardn@whl.co.uk
> > > Westland Helicopters Ltd. http://www.whl.co.uk/
> > >
> > > Disclaimer: This message does not necessarily reflect the
> > > views of Westland Helicopters Ltd.
> > >
> >
> >
>
> --
> Neil Hillard hillardn@whl.co.uk
> Westland Helicopters Ltd. http://www.whl.co.uk/
>
> Disclaimer: This message does not necessarily reflect the
> views of Westland Helicopters Ltd.
>
>
>
>
>
Received on Thu May 30 2002 - 21:49:41 MDT

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