[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: dual IP
Dear Brian Candler,
Thank you for your kind information. The problem was with the
putting private IP in Radio modem which was set as a gateway to
Internet. The problem is not solved.
I want to ask one more question.
I want give to some of the users POP account but limit to them only e-
mail. How to set for this in the router?
With regards,
Sincerely yours,
Mohan Raj Pradhan
HealthNet Nepal
Date sent: Sat, 19 May 2001 18:27:48 +0100
From: Brian Candler <B.Candler@pobox.com>
To: mpradhan@healthnet.org.np
Copies to: tcpws@psg.com
Subject: Re: dual IP
> On Sun, May 20, 2001 at 03:36:54PM +0530, mpradhan@healthnet.org.np wrote:
> > The dual IP seems working but the problem is as follows:
> >
> > If I use the valid IP in the IP address part of workstation for example:
> > IP address: 202.52.231.197
> > Subnet mask 255.255.255.224
> >
> > then I can not telnet with the private IP(192.168.0.1) but I can telnet
> > with valid IP . Earlier I could telnet with private IP even if I have put
> > valid IP in the IP part of network neighborhood of workstation.
>
> I am afraid you are making very little sense, and you will need to draw a
> diagram to explain what you are trying to do.
>
> Do you have two physically separate networks, one with private IP space and
> the other with public? e.g.
>
> Internet
> ^
> |
> Router
> 202.52.231.192/27 |<z>
> --------------+----------+--
> |<x>
> Linux box
> |<y>
> --------------+-------------
> 192.168.0.0/24
>
> Or are you using "IP aliasing" so that some boxes have two different IP
> addresses on the same network?
>
> Internet
> ^
> |
> Router
> |202.52.231.<z>
> -+------------+----------+--
> | |202.52.231.<x>
> | |192.168.0.<y>
> Other Linux box
> workstations
>
> If it is the latter, then how it works will depend on which IP address the
> 'other workstations' have and where they point default route.
>
> If an 'other workstation' has a 192.168.0 address, and points defaultroute
> at the Linux box, it should be able to see both public and private networks.
>
> If it has a public address, and points defaultroute at the router, then it
> will not be able to see the 192.168.0 network, unless you add an appropriate
> static route on the router. However in many cases you don't _want_ boxes on
> public addresses to be able to see the private network, because the NAT box
> acts as a kind of 'firewall' between the private and public networks.
>
> Windows protocols (i.e. Netbios and SMB) may get confused if you try to NAT
> them. You could configure the Linux box to allow forwarding without NAT
> between the 192.168.0 and 202.52.231.192 networks, but then you lose any
> 'firewalling' protection you may have had. I would suggest you keep all
> Windows boxes (workstationsm, NT servers etc) on private addresses. If you
> can keep them on a physically separate network, as per the first diagram
> above, then so much the better.
>
> Sorry I can't give a specific answer to your problem unless you are more
> specific about how your network is constructed.
>
> Brian.