question on static IPs and firewalls

Say you have a laptop that on your office network you assign that laptop a
static IP. You open up a file and print exception for this static IP (which
is public) on the server firewall so the laptop can connect to the server.

You want to use the same laptop at home to connect to the server. You have
a different IP at home though. Most likely you would want to request a
static IP from your ISP. Since your static IP is different at home than it
is at work, how do you configure the at home static IP? Do you have to use a
separate windows login?

Also if you have to VPN to the work network, would the connection that the
server sees be the at home static IP or an IP related to the VPN?

"biff" <(E-Mail Removed)> wrote in message
news:7C5E3557-79D9-4EEC-B3C4-(E-Mail Removed)...
| Say you have a laptop that on your office network you assign that laptop a
| static IP. You open up a file and print exception for this static IP
(which
| is public) on the server firewall so the laptop can connect to the server.

I use file and printer sharing on my server. I opened the related ports, not
just for one IP, but for every IP (unrestricted). At that point it's
unsecure, but since my ISP (for the server) blocks that ports anyway ;-)
it's not accessible from the internet.

To make it work over the internet, I know two options:
1. VPN, the user can be assigned a specific static IP by the server.
2. The other option is more interesting: by properly configuring IPSec with
preshared a key on server and all the clients, a client behind NAT/Firewall
can workaround the ports filtered by the ISP and connect to the server.
Anyone that doesn't have the key, will see the ports as filtered, since the
server will not respond to TCP connections on that port. The traffic is
carried over ESP (IP protocol 50), make shure that can pass through the
firewall.

If You have unreliable ADSL line on the client, chances are you may suffer
slow-down in speed after enabling ESP for that ports. The same applies for
the VPN if you carry it over ESP ;-) I still can't figure out why it is
about 10 times slower during day time, but at night time the speeds are
equal.


| You want to use the same laptop at home to connect to the server. You
have
| a different IP at home though. Most likely you would want to request a
| static IP from your ISP. Since your static IP is different at home than
it
| is at work, how do you configure the at home static IP? Do you have to
use a
| separate windows login?

Why not add DHCP servers both at work and home? then you won't bother to
reconfigure the IP every time. Or you can use static IPs and change it from
a script. Or establish the VPN and that interface to connect to the server.
It will always use the same IP, no mather where you are.


| Also if you have to VPN to the work network, would the connection that the
| server sees be the at home static IP or an IP related to the VPN?

It will see whichever you use to connect to it from.


George Valkov

Biff,
The key here seems to be the server firewall.
What is it that you want only your laptop to be able to do?
Anthony
http://www.airdesk.com




"biff" <(E-Mail Removed)> wrote in message
news:7C5E3557-79D9-4EEC-B3C4-(E-Mail Removed)...
> Say you have a laptop that on your office network you assign that laptop a
> static IP. You open up a file and print exception for this static IP
> (which
> is public) on the server firewall so the laptop can connect to the server.
>
> You want to use the same laptop at home to connect to the server. You
> have
> a different IP at home though. Most likely you would want to request a
> static IP from your ISP. Since your static IP is different at home than
> it
> is at work, how do you configure the at home static IP? Do you have to
> use a
> separate windows login?
>
> Also if you have to VPN to the work network, would the connection that the
> server sees be the at home static IP or an IP related to the VPN?

> "biff" <(E-Mail Removed)> wrote in message
> news:7C5E3557-79D9-4EEC-B3C4-(E-Mail Removed)...
> Say you have a laptop that on your office network you assign that laptop a
> static IP. You open up a file and print exception for this static IP
> (which is public) on the server firewall so the laptop can connect to the
> server.
>
> You want to use the same laptop at home to connect to the server. You
> have a different IP at home though. Most likely you would want to request
> a
> static IP from your ISP. Since your static IP is different at home than
> it is at work, how do you configure the at home static IP?

You don't. You just can't do what you are asking. You would have to have
the firewall allow any IP range.

> Do you have to use a separate windows login?

The Windows Login does not really have anything to do with where you are at
when you try.


> Also if you have to VPN to the work network, would the connection that the
> server sees be the at home static IP or an IP related to the VPN?

It sees the IP granted to the client when the VPN is established.

VPN is the only way to do this "right".

--
Phillip Windell

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
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