05-18-2003
Sorry, that is simply not true. We have a similar set up at home and use both DHCP and static addresses from the same address block. It works fine. Some PC get their addresses from the DHCP server (software in the Linksys router), others use assigned static IPs.
We don't do it, but the device can be configured to only allocate DHCP IPs from a small range of numbers. Unless you have a giant LAN that is using almost all the addresses, this is not a problem.
Since the poster indicated that they have a small LAN, simply assign a static IP outside of the 'normal' range of DHCP allocations.
And, if I'm not mistaken, ARP should make this moot in many DHCP servers; i.e. a good DHCP server should check its ARP cache before assiging an IP to check to see if it is in use on the segment.
For example, here is a quote from:
http://www.networkpenetration.com/dhcp_flaws.html
Quote:
Some DHCP servers issue ARP requests or ICMP pings to detect for IP addresses that may be reclaimed by the server. This is done as operating systems / interfaces do not release there assigned IP address when shutdown. Basic testing of the denial of service code successfully defeat the ARP method of reclaiming IP addresses (ICMP method was not tested) as the number and speed of requests for IP addresses was significantly higher than the number of ARP requests issued by the DHCP server (when running multiple copies of the source code in a script). The source code could be extended to sniff for ARP requests / ICMP ping requests and reply accordingly thus defeating the servers method of reclaiming addresses.
OBTW: if you are operating your own small private LAN, you don't need to be worried about the hypothetical DHCP vulnerability above.
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LEARN ABOUT XFREE86
dhcpmgr
dhcpmgr(1M) System Administration Commands dhcpmgr(1M)
NAME
dhcpmgr - graphical interface for managing DHCP service
SYNOPSIS
/usr/sadm/admin/bin/dhcpmgr
DESCRIPTION
dhcpmgr is a graphical user interface which enables you to manage the Dynamic Host Configuration Protocol (DHCP) service on the local sys-
tem. It performs the functions of the dhcpconfig, dhtadm, and pntadm command line utilities. You must be root to use dhcpmgr. The dhcpmgr
Help, available from the Help menu, contains detailed information about using the tool.
USAGE
You can perform the following tasks using dhcpmgr:
Configure DHCP service
Use dhcpmgr to configure the DHCP daemon as a DHCP server, and select the data store to use for storing network configuration tables..
Configure BOOTP relay service
Use dhcpmgr to configure the DHCP daemon as a BOOTP relay.
Manage DHCP or BOOTP relay service
Use dhcpmgr to start, stop, enable, disable or unconfigure the DHCP service or BOOTP relay service, or change DHCP server parameters.
Manage DHCP addresses
Use dhcpmgr to add, modify, or delete IP addresses leased by the DHCP service.
Manage DHCP macros
Use dhcpmgr to add, modify or delete macros used to supply configuration parameters to DHCP clients.
Manage DHCP options
Use dhcpmgr to add, modify or delete options used to define parameters deliverable through DHCP.
Convert to a new DHCP data store
Use dhcpmgr to configure the DHCP server to use a different data store, and convert the DHCP data to the format used by the new data
store.
Move DHCP data to another server
Use dhcpmgr to export data from one Solaris DHCP server and import data onto another Solaris DHCP server.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
non-zero An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWdhcm |
+-----------------------------+-----------------------------+
|Interface Stability |Evolving |
+-----------------------------+-----------------------------+
SEE ALSO
dhcpconfig(1M), dhtadm(1M), pntadm(1M), in.dhcpd(1M), dhcpsvc.conf(4), dhcp_network(4), dhcptab(4), attributes(5), dhcp(5), dhcp_modules(5)
Solaris DHCP Service Developer's Guide
System Administration Guide: IP Services
SunOS 5.10 13 Mar 2001 dhcpmgr(1M)