Internal adaptor IP address


G

Guest

Hi,

I’m wondering if there is anyway of manually setting the IP address of the
internal network adaptor that exists in a RRAS.

Current situation details: Win2K Server SP4 running RRAS. RRAS has a dynamic
link to the internet through ADSL, one NIC connects the server to a private
LAN. Internet sharing is accomplished through NAT on the RRAS. RRAS is also
configured to allow incoming VPN and dialup clients.

At the moment RRAS uses the IP address pool within itself to supply the
internal adaptor and also the remote clients with an IP address upon
connection, this address pool is on a different subnet to the private LAN so
proper IP routing takes place through the RRAS between remote and private LAN
hosts.

This all works fine, but the static IP pool allocation system is very
limiting for apply more advanced DHCP setting to remote clients. But if I
disable the pool and set the RRAS to use an external DHCP server to get IP
addresses to take full advantage of DHCP, it defaults to requesting addresses
from the same scope the private LAN hosts get theirs from, and effectively
turns the RRAS from an IP router into a sort of proxy for the remote clients
because the internal adaptor also leases its remote client IP addresses from
the private LAN scope. This is not an ideal setup in my opinion, as remote
clients get the same IP settings as the private LAN hosts, which is not what
I’d ultimately like to achieve.

I imaging if it were possible to set the internal adaptor to an IP address
on a different subnet from the private LAN, requests for IP address leases to
a DHCP server would result in leases from the scope matching the subnet the
internal adaptor was on. Resulting in something like this:

ISP and Internet
--------------------
| Public Gateway IP
/
\
/
| Public Static IP
---------^------------
| ADSL Internet Link |
| |
Private LAN | [RRAS Server] |
192.168.0.0/24 | |
_____.._________/ LAN NIC |
| | \192.168.0.1 | Remote Access Network
within RRAS
Host n .. Host 1 | | 192.168.1.0/24
| Internal Adaptor\______________.._
| 192.168.1.1/ |
|
| | Remote Host 1
... Remote Host n
-----------------------

Pretty much identical to the current setup true, except the address
192.168.1.1 is statically assigned, and the remote host addresses are least
from an external DHCP scope unique to that which the private LAN addresses
come from. Not both coming from the RRAS IP address pool.

In summery: is it possible to manually assign the internal adaptor IP
address so this is possible? One thought I had was to install a physical NIC
in the server and assign it an address on the desired remote host’s subnet
and then set RRAS to obtain its IP settings from that NIC and an external
DHCP server. It’s just an idea, not been tried yet. Probably resulting in
something like this:

ISP and Internet
--------------------
| Public Gateway IP
/
\
/
| Public Static IP
---------^------------
| ADSL Internet Link |
| |
Private LAN | [RRAS Server] |
192.168.0.0/24 | |
_____.._________/ LAN NIC |
| | \192.168.0.1 |
Host n .. Host 1 | | Remote Access
Network within RRAS
| Redundant Adaptor\ 192.168.1.0/24
| 192.168.1.1 \_____________.._
|AND Internal Adaptor / |
|
| 192.168.1.X/ Remote Host 1 ..
Remote Host n
| |
-------------------------
*with 'x' being whatever address the internal adaptor feels like asigning
itself

Regards,
Andrew Ward.
 
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B

Bill Grant

I aggree with you that using DHCP to give remotes an IP address in the
same IP subnet as the LAN machines is to be avoided in all but the simplest
network.

The process with DHCP isn't quite as you suggest. RRAS just leases a
batch of IP addresses and uses that instead of a static pool. The clients
still get their network config from RRAS, not from DHCP directly. After
connection, clients can get additional info from DHCP using DHCPINFORM.

You would not need to give the internal interface a static IP. It will
always get its IP from the static pool, so it will always be in the same IP
subnet.

Have you looked at CMAK (Connection Manager Admin Kit)? That might be a
better option to control the config of the remote clients.

Andrew said:
Hi,

I'm wondering if there is anyway of manually setting the IP address
of the internal network adaptor that exists in a RRAS.

Current situation details: Win2K Server SP4 running RRAS. RRAS has a
dynamic link to the internet through ADSL, one NIC connects the
server to a private LAN. Internet sharing is accomplished through NAT
on the RRAS. RRAS is also configured to allow incoming VPN and dialup
clients.

At the moment RRAS uses the IP address pool within itself to supply
the internal adaptor and also the remote clients with an IP address
upon connection, this address pool is on a different subnet to the
private LAN so proper IP routing takes place through the RRAS between
remote and private LAN hosts.

This all works fine, but the static IP pool allocation system is very
limiting for apply more advanced DHCP setting to remote clients. But
if I disable the pool and set the RRAS to use an external DHCP server
to get IP addresses to take full advantage of DHCP, it defaults to
requesting addresses from the same scope the private LAN hosts get
theirs from, and effectively turns the RRAS from an IP router into a
sort of proxy for the remote clients because the internal adaptor
also leases its remote client IP addresses from the private LAN
scope. This is not an ideal setup in my opinion, as remote clients
get the same IP settings as the private LAN hosts, which is not what
I'd ultimately like to achieve.

I imaging if it were possible to set the internal adaptor to an IP
address on a different subnet from the private LAN, requests for IP
address leases to a DHCP server would result in leases from the scope
matching the subnet the internal adaptor was on. Resulting in
something like this:

ISP and Internet
--------------------
| Public Gateway IP
/
\
/
| Public Static IP
---------^------------
| ADSL Internet Link |
| |
Private LAN | [RRAS Server] |
192.168.0.0/24 | |
_____.._________/ LAN NIC |
| \192.168.0.1 | Remote Access
Network
within RRAS
Host n .. Host 1 | | 192.168.1.0/24
| Internal Adaptor\______________.._
| 192.168.1.1/ |
|
| | Remote
Host 1 .. Remote Host n
-----------------------

Pretty much identical to the current setup true, except the address
192.168.1.1 is statically assigned, and the remote host addresses are
least from an external DHCP scope unique to that which the private
LAN addresses come from. Not both coming from the RRAS IP address
pool.

In summery: is it possible to manually assign the internal adaptor IP
address so this is possible? One thought I had was to install a
physical NIC in the server and assign it an address on the desired
remote host's subnet and then set RRAS to obtain its IP settings from
that NIC and an external DHCP server. It's just an idea, not been
tried yet. Probably resulting in something like this:

ISP and Internet
--------------------
| Public Gateway IP
/
\
/
| Public Static IP
---------^------------
| ADSL Internet Link |
| |
Private LAN | [RRAS Server] |
192.168.0.0/24 | |
_____.._________/ LAN NIC |
| \192.168.0.1 |
Host n .. Host 1 | | Remote Access
Network within RRAS
| Redundant Adaptor\ 192.168.1.0/24
| 192.168.1.1
\_____________.._ |AND Internal Adaptor /
|| 192.168.1.X/ Remote Host
1 .. Remote Host n
| |
-------------------------
*with 'x' being whatever address the internal adaptor feels like
asigning itself

Regards,
Andrew Ward.
 

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