How do you configure at DHCP(d) reservation in a Cisco ASA 5505 v.7.2?

Try this from a # prompt:

ip dhcp pool Server_static
host 10.0.0.10 255.255.255.0
client-identifier 0102.0010.0012.34 < the MAC address of the client with a leading 01 to identify it as a windows client (aauming its a windows client).

Hi 2PiFL:

Your config is for Cisco IOS not ASA / PIXOS 7.  This is my current DHCP config:

dhcpd dns 71.252.0.12 68.237.161.12
dhcpd ping_timeout 10
dhcpd domain domain.local
!
dhcpd address 192.168.5.100-192.168.5.131 inside
dhcpd enable inside

Thanks!

I will exclude the address from the range and assign the IP statically.

Thanks.

One way we use to get around this is to put a hardcoded arp address for a device, and let it's IP address be within the pool.
arp inside 10.1.1.5 001e.c966.4a34
arp inside 10.1.1.10 0000.55d1.07b5
arp inside 10.1.1.12 000c.77af.af5f  
dhcpd address 10.1.1.5-10.1.1.50 inside
dhcpd dns 154.164.1.8 151.164.1.7 interface inside
dhcpd domain microsoft.com interface inside
dhcpd option 150 ip 10.1.1.10 interface inside
dhcpd enable inside

Genius!

Sadly, I have tried the hardcoded ARP addresses as WyleHou suggested with Cisco ASA 8.3(2) / ASDM 6.3(5) and it does not work. The clients just get any old DHCP address and not necessarily one that was hard-coded in the ARP table. Like innovexx, I have had to resort to assigning static IP's. The only other workaround would be to disable DHCP on the firewall and pull an old router or even an old Linksys 'home' router out of the junk drawer that has DHCP with reservations on it and use that.