Spanning Tree Bpdu Support; An Example Bpdu Relaying Scenario - D-Link NetDefend DFL-210 User Manual

4.7.4. Spanning Tree BPDU Support

• Name: HTTP-WAN-to-DMZ
• Action: SAT
• Service: http
• Source Interface: wan
• Destination Interface: dmz
• Source Network: all-nets
• Destination Network: wan_ip
• Translate: Select Destination IP
• New IP Address: 10.1.4.10
6. Click OK
7. Go to Rules > IP Rules > Add > IPRule
8. Now enter:
• Name: HTTP-WAN-to-DMZ
• Action: Allow
• Service: http
• Source Interface: wan
• Destination Interface: dmz
• Source Network: all-nets
• Destination Network: wan_ip
9. Click OK
4.7.4. Spanning Tree BPDU Support
NetDefendOS includes support for relaying the Bridge Protocol Data Units (BPDUs) across the
NetDefend Firewall. BPDU frames carry Spanning Tree Protocol (STP) messages between layer 2
switches in a network. STP allows the switches to understand the network topology and avoid the
occurrences of loops in the switching of packets.
The diagram below illustrates a situation where BPDU messages would occur if the administrator
enables the switches to run the STP protocol. Two NetDefend Firewalls are deployed in transparent
mode between the two sides of the network. The switches on either side of the firewall need to
communicate and require NetDefendOS to relay switch BPDU messages in order that packets do not
loop between the firewalls.
Figure 4.17. An Example BPDU Relaying Scenario
Implementing BPDU Relaying
The NetDefendOS BDPU relaying implementation only carries STP messages. These STP messages
can be of three types:
• Normal Spanning Tree Protocol (STP)
• Rapid Spanning Tree Protocol (RSTP)
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Chapter 4. Routing