Cisco ASA Port Forwarding / DHCP IP Address reservation

[markangelolim]

Hi Everyone,

need help on my installation of ASA 5512-x, my first concern is i'm configuring port forwarding using the public servers module under Configuration>Firewall>Public Servers when i add a Public Server i will indicate the following:

Private Interface : Inside

Private IP address: 192.168.1.x

Private Service: 3389

Public Interface: Outside

Public IP Address: "example: 210.4.100.1"

Public Service 3380

now my problem is after putting all the information when i click OK it will prompt me this error "The public address cannot be the same as the public interface address". I can use another public IP address but what if i only have one public IP? and what if changing the declared public IP address is not an option? I tried creating Port Forwarding using the static NAT but it just prompt me the same error. Is there any way i can solve this without changing the public IP address?

my second concern is does ASA 5512-x can support DHCP IP address reservation through MAC Address? i've been reading through other forums and it seems that this feature is not supported, i just want to confirm maybe 5512-x can support this "simple feature". Thanks in advance for the reply.   

[Seb Rupik]

Hi there,

I can't help you with the ASDM error but what you need can be acheived with NAT and the CLI:

!

object network rdp_server
host 192.168.1.x

!

object network rdp_server
 nat (inside,outside) static interface service tcp 3389 3380

!

cheers,

Seb.

[Jay Johnston · Accepted solution]

The DHCP reservation feature is now supported on ASA in version 9.13(1) and later

Example:

Magnus-5506-Desk# sh run dhcpd
dhcpd dns 192.168.1.22
dhcpd domain cisco.com
dhcpd option 4 ip 172.18.124.1
!
dhcpd address 192.168.100.100-192.168.100.200 inside
dhcpd enable inside
dhcpd reserve-address 192.168.100.199 ecb5.fa0f.988b inside
!
Magnus-5506-Desk#