how to configure network with more than 1 public IP ?

[scott]

Hi,

I have several public IP and am looking for information on how to configure
my network. for example:

--------------------------------------------------
net
v
v
router > > switch > > iis 1
v v v
v v v
v iis2 mail server
v
firewall
v
v
switch > > lan servers
v
v
lan clients
--------------------------------------------------

- do i need a special router that can deal with 16 public IPs ?
- i would assign a public IP to IIS1 + IIS2 + mail server + router external
(if this makes sense).
- all lan servers + lan clinets would be on a private IP range.

I thought my ISP implied that as I have several public IPs that i cant use
private IP range. This does not make sence.

Im just tying to figure out how to organise the routing in this environment.

Thanks for any information and your time.
Scott.

 

[John Wunderlich]

- do i need a special router that can deal with 16 public IPs ?
- i would assign a public IP to IIS1 + IIS2 + mail server + router
external (if this makes sense).
- all lan servers + lan clinets would be on a private IP range.

I thought my ISP implied that as I have several public IPs that i
cant use private IP range. This does not make sence.

Im just tying to figure out how to organise the routing in this
environment.

I am assuming that you either have a cable modem or DSL modem. If your
ISP has allocated more than one IP address to you then your modem
will/should handle acquiring the IP addresses if you have dynamic
(DHCP) IP addresses or you can hard set fixed IP addresses if your ISP
has given you fixed addresses. Your network should look something like
this:


Internet
v
v
Cable/DSL Modem
v
v
Switch/Hub > > > Public-addressed computers
v
v
Router > > > Private IP Networked computers
v
v
Switch/Hub > > Additional Private networked computers/devices

HTH,
John

 

[Phillip Windell]

That would work perfectly with a T1 Line if the Cable/DSL Modem was a
standard router like a Cisco 2500 or something, but it wouldn't work like
that with DSL or Cable like it would with a T1.

With a T1, the router at each end has typically a "two-host subnet" off of
the Serial Interfaces between to two routers that no one ever really sees.
In other words the Router at the customer's site has two public IP
subnets,...#1 the public range of IP's granted to the customer on the
customer's side of the Router and,... #2 is the other subnet on the ISP's
side of the Router using IP#s that belong only to the ISP, and most
customers are never aware of, that connects it to the ISP's Router at the
other end.

DSL and Cable is designed differently and there is probably more than one
way to do it. The ISP would have to be contacted to find out the method
they expect to be used in order to work with the design they had in mind.

The Cable/DSL Modem is a Layer2 device and is not suitable. However the
Cable/DSL Router is actually a "NAT Box" and not a real router, therefore
also not suitable.

Option#1
It would require a Cable/DSL Router that behaves truely as a router and
doesn't do NAT (there may not even be such a thing). It would have the IP#
Range granted to the customer on the customer side of the router while
having a separate public IP range on the ISP side of the same router that
the customer wouldn't be aware of. That is the theory anyway,...it is
similar to the T1 setup, but I have never seen DSL or Cable done that way
and don't know if it even can be done.

Option#2
It would use a normal Cable/DSL Router "NAT box". All the customers IP#s
would be bound to the same interface of the router/nat box. Then these
IP#s would have to be "one-to-one NAT'ed" to privately addressed machines on
the customer side of the box. This would be "clunky" and unflexable in my
opinion, but I bet that is what the ISP intends the customer to do.

Anyway,...the ISP will have to be consulted and the customer is pretty much
"stuck" with whatever design the ISP has in mind.

 

[scott]

Thanks for the reply guys.

Thats given me a few more areas to explore.
Scott.