Cisco 3845 - Security Bundle Router Software Manual page 195

Chapter 9 Configuring Interfaces
Figure 9-2
By default, the Ethernet management port is enabled. The switch cannot route packets from the Ethernet
management port to a network port or receive routed packets from a network port.
Even though the Ethernet management port does not support routing, you might need to enable routing
protocols on the port. For example, in
management port when the PC is two or more hops away from the switch and the packets must pass
through two or more Layer 3 devices to reach the PC.
Figure 9-3
In Figure
routing process, the routes are propagated in this manner:
The routes from the Ethernet management port are propagated through the network ports to the
•
network.
The routes from the network ports are propagated through the Ethernet management port to the
•
network.
Because routing is not supported between the Ethernet management port and the network ports, traffic
cannot be sent or received between these ports. If traffic is sent or received, data packet loops occur
between the ports, which disrupts the switch and network operation. Configure route filters to avoid
routes between the Ethernet management port and the network ports and to prevent the loops.
OL-23400-01
Connecting a Switch to a PC
Ethernet
management
Switch
port
Network
ports
Network
cloud
Network Example with Routing Protocols Enabled
Ethernet
management
Switch
port
Network
ports
Network
cloud
9-3, if the Ethernet management port and the network ports are associated with the same
Figure 9-3, you must enable routing protocols on the Ethernet
Network
cloud
Cisco ME 3800X and 3600X Switch Software Configuration Guide
Using the Ethernet Management Port
PC
PC
9-11