adsl with wi-fi gateway

[roshanverg]

hello'

this is a small office with 15 computers. there is no domain users login to pcs. no servers. DNS and mail servers are hosted outside.

1, usrs access internet via CISCO WI-FI ADSL gateway .  ISP provide dynamic IPS no static IPS.

REQUIREMENTS

1. SET UP A DOMAIN AND INTERNAL EMAIL SERVER

2.provide security for wi-fi router.

is it possible with dynamic ips / how ?

[IAN WHITMORE]

Well it is possible. You just need to talk to your provider and ask them to give you a couple of static IP addresses for your servers...will they do that? Depends on your contract and if they are nice. All they have to do is alter your DHCP pool and give you a few addresses.

If they are not nice you could always create your own private network and put a router inbetween your network and the ISP and use NAT. Will the provider like that? Maybe not so it's best to talk to them.

The security for your WiFi router is just a case of access-lists and WPA2 etc. But without more details I can't help you much.

HTH.

Ian

[roshanverg]

hi ian

thankx for the reply.  unfortunateley it is impossible to get static ips from isp according to the contract.

the existing wi-fi router dhcp pool has 192.168.1.x private addrees range.  is it poosible for me to use several addreses form this pool as my server ips? ( if i reserve those address from pool and configure static ips in the servers ). all the desktop use ips in the same range

also wi fi router has a built in firewall how can i use this to secure the internal network ?

[IAN WHITMORE]

Well if your ADSL router is doing the DHCP you can exclude addresses and use them as static IPs for your server.

Here is a very in-depth guide on that and everything DHCP related on Cisco routers:

http://www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfdhcp.html

The fact that you have a private IP address range means that to go the internet you are using NAT which is protection in itself (somewhat). You probably have the firewall already enabled on the router for this. So the internal network should already be secured.

I don't know what model router you have exactly because there are other optoins depending on the router (IPS etc). As far as your wifi clients are concerned you should be using at a minimum WPA, preferrably WPA2. In a network your size I doubt you will use 802.1x or anything more advanced.

If you want your "new"servers available from the internet you will to perform some NAT on the firewall and use access-lists to allow access only to specific IP's and ports, but I'm getting more complicated here.

HTH,

Ian