Question ID : 297
Created on 2013-07-07 at 7:23 PM
Author : Guru Corner [firstname.lastname@example.org]
Online URL : http://kb.guru-corner.com/question.php?ID=297
Article Applies To:
Transparent mode simulates the bridging of WAN-side IP addresses/subnets onto internal interfaces, such as the LAN or DMZ interface, by means of controlling the ARP and routing behavior for the affected addresses. Transparent Mode allocations are extremely flexible, allowing for multiple internal interfaces in different zones to simultaneously operate in Transparent Mode, as long as the address assignments remain unique and non-overlapping. Transparent mode can be useful in environments where it is not possible to change existing internal IP addressing, or where it is necessary to deploy a SonicWALL in a non-interruptive, in-line fashion.
Transparent Mode works on a SonicWALL by defining a “Transparent Range” address object associated with the WAN subnet. The “Transparent Range” defines which external (WAN side) IP addresses the SonicWALL will consider to be attached to an internal interface. The Transparent Range object can be a Host, Range, or group of Host or Range Address Objects. Addresses within the Transparent Range will not be NAT’d on egress from the WAN interface, instead, they will retain their original source IP addresses.
Configuring Interfaces in Transparent Mode
Transparent Mode enables the SonicWALL security appliance to bridge the WAN subnet onto an internal interface. To configure an interface for transparent mode, complete the following steps:
Step 1 Click on the Configure icon in the Configure column for Unassigned Interface you want to configure. The Edit Interface window is displayed.
Step 2 Select an interface.
•If you select a configurable interface, select LAN or DMZ for Zone.
•If you want to create a new zone for the configurable interface, select Create a new zone. The Add Zone window is displayed.
Step 3 Select Transparent Mode from the IP Assignment menu.
Step 4 From the Transparent Range menu, select an address object that contains the range of IP addresses you want to have access through this interface. The address range must be within the WAN zone and must not include the WAN interface IP address. If you do not have an address object configured that meets your needs:
a. In the
Rangemenu, select Create New Address Object.
b. In the Add Address Object window, enter a name for the address range.
a. For Zone Assignment, select WAN.
b. For Type, select:
Step 5 Enter any optional comment text in the Comment field. This text is displayed in the Comment column of the Interface table.
Step 6 If you want to enable remote management of the SonicWALL security appliance from this interface, select the supported management protocol(s): HTTP, HTTPS, SSH, Ping, SNMP, and/or SSH. To allow access to the WAN interface for management from another zone on the same appliance, access rules must be created.
Step 7 If you want to allow selected users with limited management rights to log directly into the security appliance through this interface, select HTTP and/or HTTPS in User Login.
Configuring Advanced Settings for the Interface
If you need to force an Ethernet speed, duplex and/or MAC address, click the Advanced tab. The Ethernet Settings section allows you to manage the Ethernet settings of links connected to the SonicWALL. Auto Negotiate is selected by default as the Link Speed because the Ethernet links automatically negotiate the speed and duplex mode of the Ethernet connection. If you want to specify the forced Ethernet speed and duplex, select one of the following options from the Link Speed menu:
•1000 Mbps - Full Duplex ()
•100 Mbps - Full Duplex
•100 Mbps - Half Duplex
•10 Mbps - Full Duplex
•10 Mbps - Half Duplex
You can choose to override the Default MAC Address for the Interface by selecting Override Default MAC Address and entering the MAC address in the field. Check Enable Multicast Support to allow multicast reception on this interface.
Caution: If you select a specific Ethernet speed and duplex, you must force the connection speed and duplex from the Ethernet card to the SonicWALL security appliance as well.
Configuring the hosts connected to the Transparent interface:
The hosts connected to the X2 interface should be configured with the IP addresses within the Transparent Range. The default gateway could either be the upstream ISP router address or the SonicWALL WAN interface IP. Once the hosts are configured appropriately they will be able to go online with the IP address assigned to them without being NAT'ed. Conversely, the hosts can be reached from the WAN side of the SonicWALL with the IP address assigned to them provided a WAN > DMZ Allow rule exists.
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