DHCP Reservations

I'm not quite sure I understand your question.

Many home-based NAT routers offer a DHCP service, and some of those offer 'static DHCP reservations'. This is typically done in the router by binding the IP to the MAC address of the specific PC.

The ReadyNAS DHCP service does not appear to have this feature. If you are using the ReadyNAS as the DHCP server, then you may have to resort to assigning static addresses to those clients that require them. Having said that, if you are using the built-in DHCP server on the NAS, you may be able to tweak the config file to do what you want (you need SSH access and a bit of *nix background to accomplish this, although I may be able to give you a hand --- I just need to do some investigation).

If I misunderstood the question/problem, please let me know.

-Dave

You understand perfectly. I didn't know you could SSH into the ReadyNAS. I just tried it and it didn't work for me. I'm pretty comfortable in *NIX so if you can tell me how I can get ssh access I may be able to do it myself. Many thanks!!!

There's a link on the main http://www.readynas.com page to "Add-ons".

If you're running v.4.x, you can install the "EnableRootSSH" add-on.

username = root
password = your admin p/w

-Dave

I did a little research on the DHCP server & it appears as though it's based on UDHCP (http://udhcp.busybox.net/). As far as I can tell, the version included with the ReadyNAS does not support static reservations (see quote below). You could increase the lease time from 900 to 864000 seconds (15 minutes to 10 days).

Perhaps you can add this to "Feature Request".

Anyhow, here are some of the specifics for the ReadyNAS.

Path to config file on ReadyNAS:

/etc/default/config/etc/udhcpd.conf

My current settings (with DHCP disabled):

start 		192.168.168.1
end		192.168.168.167
interface	eth0
opt	dns	
opt	subnet	255.255.255.0
opt	router	192.168.168.168
opt	domain	
option	lease	900

Sample config file showing various options (from http://udhcp.busybox.net/udhcpd.conf):

# Sample udhcpd configuration file (/etc/udhcpd.conf)

# The start and end of the IP lease block

start 		192.168.0.20	#default: 192.168.0.20
end		192.168.0.254	#default: 192.168.0.254

# The interface that udhcpd will use

interface	eth0		#default: eth0

# The maximim number of leases (includes addressesd reserved
# by OFFER's, DECLINE's, and ARP conficts

#max_leases	254		#default: 254

# If remaining is true (default), udhcpd will store the time
# remaining for each lease in the udhcpd leases file. This is
# for embedded systems that cannot keep time between reboots.
# If you set remaining to no, the absolute time that the lease
# expires at will be stored in the dhcpd.leases file.

#remaining	yes		#default: yes

# The time period at which udhcpd will write out a dhcpd.leases
# file. If this is 0, udhcpd will never automatically write a
# lease file. (specified in seconds)

#auto_time	7200		#default: 7200 (2 hours)

# The amount of time that an IP will be reserved (leased) for if a 
# DHCP decline message is received (seconds).

#decline_time	3600		#default: 3600 (1 hour)

# The amount of time that an IP will be reserved (leased) for if an
# ARP conflct occurs. (seconds

#conflict_time	3600		#default: 3600 (1 hour)

# How long an offered address is reserved (leased) in seconds

#offer_time	60		#default: 60 (1 minute)

# If a lease to be given is below this value, the full lease time is
# instead used (seconds).

#min_lease	60		#defult: 60

# The location of the leases file

#lease_file	/var/lib/misc/udhcpd.leases	#defualt: /var/lib/misc/udhcpd.leases

# The location of the pid file
#pidfile	/var/run/udhcpd.pid	#default: /var/run/udhcpd.pid

# Everytime udhcpd writes a leases file, the below script will be called.
# Useful for writing the lease file to flash every few hours.

#notify_file				#default: (no script)

#notify_file	dumpleases 	# <--- usefull for debugging

# The following are bootp specific options, setable by udhcpd.

#siaddr		192.168.0.22		#default: 0.0.0.0

#sname		zorak			#default: (none)

#boot_file	/var/nfs_root		#default: (none)

# The remainer of options are DHCP options and can be specifed with the
# keyword 'opt' or 'option'. If an option can take multiple items, such
# as the dns option, they can be listed on the same line, or multiple
# lines. The only option with a default is 'lease'.

#Examles
opt	dns	192.168.10.2 192.168.10.10
option	subnet	255.255.255.0
opt	router	192.168.10.2
opt	wins	192.168.10.10
option	dns	129.219.13.81	# appened to above DNS servers for a total of 3
option	domain	local
option	lease	864000		# 10 days of seconds

# Currently supported options, for more info, see options.c
#subnet
#timezone
#router
#timesvr
#namesvr
#dns
#logsvr
#cookiesvr
#lprsvr
#bootsize
#domain
#swapsvr
#rootpath
#ipttl
#mtu
#broadcast
#wins
#lease
#ntpsrv
#tftp
#bootfile

From http://forum1.netgear.com/showthread.php?p=105292

March 18th, 2008, 01:25 AM yschandra yschandra is offline Junior Member Join Date: Mar 2008 Posts: 1 Post Re: Problem with DG834G v4 address reservation Exactly same problem exists with all version of DG834GT firmware including latest V1.02.14. I found that the problem is with the udhcpd version used which is 0.9.7. This version doesn't have a feature of static leases (reserve IP based in MAC). I pulled out SVN snapshot of udhcpd which has static leases feature and compile and created custom firmware and tested, it works properly. If my guess is right DG834G v4 firmware base is also using udhcpd which doesn't support this feature which Netgear does not seem have tested properly. If some one feels adventure enough to pull the sources and try to building firmware with new udhcpd I am there to help.

-Dave

i don't know if anything has been fixed in the meantime, but i did a:
cp /etc/udhcpd.conf /etc/udhcpd.backup
apt-get update
apt-get install udhcpd
cp /etc/udhcpd.backup /etc/udhcpd.conf

This has upgraded my udhcpd to a newer version. Afterwards I could add the following line to the bottom of my udhcpd.conf using vi:
static_lease 00:de:ad:be:ef:00 1.2.3.4

Please replace the "00:de:ad:be:ef:00" with the actual mac address and "1.2.3.4" with the desired ip address.

What is even cooler is that you can add the following line as well if you want to manage the addresses using your DNS server (in case you run a DNS server on your box or somewhere else):
static_lease de:ad:00:00:be:ef this.is.my.hosts.dns.name.

In this case replace the mac address "de:ad:00:00:be:ef" with the actual mac address of the device and "this.is.my.hosts.dns.name." with a fully qualified dns name that resolves to the desired ip address. Quite nice, because if doing it like that an address change takes place within your DNS-Server settings only, while otherwise you got to make a change to DHCP & DNS settings.

Maybe this helps a little bit....

Hi, Are these instruction for setting up DHCP reservations (by MAC address) applicable to the ReadyNAS DUO (sparc)? Neil