Overview
When enabled in the
, the DHCP client acquires the interface's IP configuration dynamically from a reachable DHCP server. Once initial configuration takes place, the DHCP client can be enabled on a per logical interface basis in the
. DHCP address assignment can be configured on both VLAN interfaces (VLAN 1 IP, VLAN 2 IP, etc) and port specific interfaces (i.e., Ethernet 1 IP, Ethernet 2 IP). DHCP is not supported on loopback or Admin interfaces. When enabled in the
, the DHCP client configures the following interface-specific attributes:
- IP Address
- IP Netmask
- IP Broadcast Address
The DHCP client also dynamically configures several node-level attributes. Upon configuration of these attributes, any existing configuration is removed.
- Default Route
- DNS Server(s)
- NTP Server(s)
- Domain Name
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Although enabling DHCP on multiple interfaces is supported, the recommendation is to enable only one interface with DHCP, or unexpected results may occur. If using multiple interfaces, you should assign the additional IP addresses via static configuration. |
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In case of IP lease renew for DHCP, or change of static IP where the new IP address is different, the existing calls will be disconnected. |
Prerequisites - Setting up the DHCP client
In order to use the DHCP client on your network, the DHCP server must be on the network.
Using DHCP for System Access During Initial Configuration
When a system is in Factory Default mode, the DHCP client is enabled on Ethernet 1 and the DHCP server is enabled on Ethernet 2. This allows you to connect to the
without having to assign your computer a static IP.
The DHCP client acquires an IP address from DHCP server. During DHCP lease acquisition, the
provides the DHCP server with its hostname, which is set to the
node's hardware ID. If your network's DHCP and DNS servers have Dynamic DNS configured properly, the DHCP server will inform the DNS server that the
is reachable via its default hostname (i.e., the
's serial number). As a result, during initial configuration, you can access the
node on the network by directing your PC's browser to the node's serial number (i.e.,
A4025511270005.yourdocaldomain.doc). The serial number can be found on the back of the
unit (i.e., A4025511270005).
This default configuration is present only until initial configuration is complete. Following that, you can configure any desired DHCP functionality. The default IP addresses assigned before initial configuration are as follows:
SBC 2000 only:
- SBC 2000 and SBC 1000:
- Ethernet 1 – Acquires an address via a connected DHCP server.
- Ethernet 2 – Default address of 192.168.129.2. You can either statically assign an address to the PC in the 192.168.129.x subnet (e.g. 192.168.129.8) or the 's DHCP server will assign one (192.168.129.3).
How a DHCP Client works - Example Scenario
The DHCP client can be configured on any interface in any network layout as along as there is a DHCP server. For example, in a typical
branch office deployment, the
will have
Ethernet 1 connected to the ISP WAN, and
Ethernet 2 connected to the office LAN. In this scenario, the
's Ethernet 1 interface will acquire an IP address via DHCP from the ISP provided internet modem.
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1 | DHCP Client
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