Static IP Issues on Network

[hotfoot]

I have had repeated instances where visitors not previously configured for static IPs on my network, come in, try to log on and lock the system up. I have to shut down the T1 modem/router, firewall and switches to bring the sytem back up. DHCP users on the same network, but different switches, are not effected. Any ideas on how to prevent this?

[dcomiskey]

Is there a reason you have to have static IPs?

[EWB-James]

Personally I have never been a fan of static IPs unless it is a server. Instead switch them to reserved DHCP. They will usually keep the same IP if there is common activity.

What kind of system is this exactly?

[markjohnl]

Hi James,

I agree with the other postings. On a private network, static IP's increase the administrative overhead for managing your network. For a small business working with a single IP range you would be better defining a DHCP scope of say 192.168.0.10 to 192.168.0.254. Your server (if you have one) or firewall will probably include this feature. Not only will the DHCP server dole out IP addresses and the relevant subnet mask, but they can also be used to define the default gateway (probably your firewall or Proxy server IP address) as well as primary and secondary DNS servers (again, either your firewall or server IP).

Manually configure your firewall, server(s) and printers with IP addresses from the set of free ip's in the range .1 to .9 (you can define the size of your dhcp scope to cater for the number of fixed IP's required - Don't limit it, assume that your network will grow. Leaving the first 50 free will do no harm. You can adjust the scope at any time should you ever run out of addresses.

alternatively, printers can have IP addresses reserved for them. You will need their hardware address (sometimes referred to as the mac address). All windows servers support this feature. If you are using your firewall, it may or may not let you do this.

The hardware address of the printer is often found as a label on the printer, or on the print server box. If not, most printers will let you print a configuration page listing this info. Failing that, go to a command prompt and telnet to the printers current IP, then type / and hit return. The hardware address will look something like this '00-03-e5-3f-cd-de'.

Hopefully this will help in some way.

Regards,

Mark