User`s guide

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How to Configure a DHCP Connection
If the IP address is dynamically assigned by your ISP, follow the instructions in this article to configure the interface.
Before You Begin
If your ISP provides a modem, connect the Ethernet port of the modem to a free network interface on the back of your Barracuda Firewall. Use
the Ethernet cable that is delivered with the modem. If a cable was not delivered with the modem, determine if the modem must be connected to
another device with a standard Ethernet cable or a crossover cable.
Configure the WAN Interface
Go to the page.NETWORK > IP Configuration
In the section, click .Dynamic Interface Configuration Add Dynamic Network Interface
Enter a name for the new connection.
Set to .Network Protocol DHCP
From the list, select the network interface that the ISP modem is connected to on the Barracuda Firewall.Network Interface
Set to . Classification WAN
Configure the remaining settings for your network requirements.
In the field, enter the MTU size. If the MTU size is too large, network packets passing the ISP line are fragmented andMTU
might decrease the performance of your network performance. For the correct MTU size, contact your ISP.
To automatically introduce a network route for this Internet connection, set to .Create Default Route Yes
For the initial configuration, keep the default value of . In a multiprovider configuration, the Barracuda FirewallMetric 100
chooses the interface with the lowest metric for outgoing traffic.
To use the DNS server that is assigned by your ISP, set to . The Barracuda Firewall then uses the DNSUse Assigned DNS Yes
servers of the ISP for DNS requests.
To make the Barracuda Firewall reachable with a unique identifier (DNS-resolvable name), set to andUse Dynamic DNS Yes
enter your DynDNS credentials.
Specify the for this link. The connection timeout specifies the time in seconds that the Barracuda FirewallConnection Timeout
waits for an IP address to be assigned. If the defined limit is exceeded, the link is marked as unreachable.
To start the link automatically, set to .Connection Start Method Automatic
T o manually start and stop the link, To control the link, go to the set toConnection Start Method Manual. Dynamic Network
page.section of the Interfaces NETWORK > Interfaces
To add IP addresses to monitor the Internet connection beyond the gateway, add a target IP address to the Health Check
list.Target
Click .Add
At the top of the page, click on the warning message to execute the new network configuration.
For more information about the DynDNS service, visit .http://dyn.com/dns/