Specifications

4 Barracuda Link Balancer Administrator’s Guide
VLAN Support
The Barracuda Link Balancer supports Layer 2 VLANs.
High Availability
The Barracuda Link Balancer supports High Availability configurations where two Barracuda Link
Balancers are deployed as an active-passive pair.
Persistence
The Barracuda Link Balancer automatically tracks the IP addresses of each client / source and
corresponding server / destination. As long as the source and destination IP address pair are the same,
traffic between them will use the same link. In addition, any one source and destination IP address
pair will be tied to a specific link through about 15 minutes of inactivity. If traffic from an already
tracked source IP address is detected, it may be sent on a different link if the destination IP address is
unique.
Bandwidth Management and Quality of Service (QoS)
The Barracuda Link Balancer includes software that can automatically prioritize critical Internet
applications. For example, you can assign priority to Web browsing and email while giving peer-to-
peer applications and media streaming a lower priority. In this way, you can ensure that bandwidth-
intensive applications do not interfere with business-critical operations.
Traditional Firewall
The Barracuda Link Balancer incorporates standard firewall functionality, including:
• Network Address Translation (NAT):
• IP masquerading - Clients in the internal network are protected from the Internet. All
Internet services appear to be provided by the Barracuda Link Balancer firewall, while
the internal clients remain invisible.
• 1:1 NAT - You can directly assign external addresses to internal servers. Ideal for hosting
internal applications or services requiring regular outbound requests such as SMTP, 1:1
NAT provides a secure method to match additional external addresses with a single
internal server for inbound and outbound traffic.
• Port forwarding (or Port Address Translation) - The traffic to the same port across one or
more multiple links is directed to an internal client.
• Many to 1 NAT - One internal server may receive traffic from more than one WAN link.
You can achieve this by creating 1:1 NAT rules or port forwarding rules.
• IP access lists - Use IP access lists to allow or deny access, either inbound or outbound, to
remote networks, clients, applications, services and ports.
• Port blocking.
• Assistance in preventing and mitigating distributed denial of service attacks (DDoS).