Additional Info on Accessing the DS
This topic provides additional information on the access options available for the target DS.
The target DS can be selected from the list (using Select DS button ) or its address and access parameters can be input manually. The first option is usually more convenient and requires less manual input and decisions on your behalf.
Specifying the target address
The target DS can be specified either by its IP-address or MAC-address:
| • | When Enable MAC-->IP mapping option is not checked the DS is specified by its IP-address. |
| • | When Enable MAC-->IP mapping option is checked the DS is specified by its MAC-address. If the DS is running with DHCP enabled its IP-address may eventually change but the MAC-address will remain the same. This option exists to make the communications with this DS "IP-address independent": each time the VSP needs to connect to the DS it will find out the current IP-address of the DS with the target MAC-address, and only then access this IP-address. The MAC-->IP mapping feature only works for local Device Servers. If the target DS is remote it can only be specified by its IP-address. |
When you choose the DS from the list (through the Select DS button) the Wizard selects or deselects the mapping option automatically:
| • | Mapping is deselected if the DS is not local (no matter the DS is running with DHCP enabled or disabled). |
| • | Mapping is deselected if the DS is local but is running with DHCP disabled (DHCP (DH) setting is 0). |
| • | Mapping is selected if the DS is local and is running with DHCP enabled (DHCP (DH) setting is 1). |
Specifying the access method and port
Besides the IP (or MAC) you need to specify the access method and access port for this DS. Access method is the way the Wizard will access the DS in order to program it. Access port is the port to which the Wizard will send its programming commands. These options are not directly related to how the VSP will be accessing the DS, they just specify how the Wizard is going to access the DS.
There are two access methods:
| • | When out-of-band (UDP) access method is selected the Wizard communicates with the DS using command UDP datagrams sent to the command port 65535 of the DS. Out-of-band commands offer a primary way of network programming that requires no preliminary setup on the DS side. This access method is suitable for all local Device Servers. It will also work with remote Device Servers unless the UDP traffic is banned by the network routers (firewalls, etc). |
| • | When inband (TCP) access method is selected the Wizard communicates with the DS by sending commands through the TCP connection established to the data port of the DS (this is the number defined by the Port Number (PN) setting of the DS). Inband (TCP) commands provide a secondary method of network programming that can be used in situations when out-of-band UDP access is impossible (for remote Device Servers). The downside is that a certain pre-programming must be done on the DS before it can be accessed using inband access method- read preparing the DS for inband access for step-by-step instructions. |
When you select the DS from the address book (through the Select DS button) the Wizard copies the access method and access port from the address book entry.