Networking Blog

Cisco ME 3400 series switches are designed to meet the needs of Metro service providers. Introduce brand new concept and features to make the product easier to manage, deploy, and troubleshoot. One of new features is the new concept of UNI/NNI Port Types.

• UNI – User Network Interface
• NNI – Network Node Interface

Based on the port type, certain features/behaviors are enabled or disabled to ease configuration, deployment, and troubleshooting.

UNI ports will not do local switching by default,  for example no local switching on UNI protects customers from each other ( host A dosn’t see host B ), and Control Plane Security  (CPS) is enabled, CPS protects against DoS attacks.

By default UNI ports:

• not switching local traffic, for example no local switching on UNI protects customers from each other ( host A dosn’t see host B ).
• Control Plane Security  (CPS) is enabled, CPS protects against DoS attacks.
• using multiple UNI ports on the same ME 3400, up to 8 UNI ports can be configured to do local switching.

NNI ports:

• For ME 3400-24TS, by default, the 2 SFP ports are NNI port-type
• For ME 3400G-12CS and ME 3400G-2CS, by default, the SFP-only ports are NNI port-type
• There can be a maximum of 4 ports defined as NNI ports (applicable to ME 3400-24TS and ME 3400G-12CS, all 4 ports can be configured as NNI on ME 3400G-2CS)

NOTE: In 12.2(25)SEG and later releases—Metro IP Access Image, all ports can be optionally configured as NNI (not limited to 4).

To configure port type:

me3400#conf t
me3400(config)#int gi0/10
me3400(config-if)#port-type ?
  nni  Set port-type to NNI
  uni  Set port-type to UNI

Configuring UNI ports to do local switching (forwarding traffic between UNI ports)

Port Gi0/1 and Gi0/2 on Cisco me3400-12G are UNI ports, belongs to VLAN 2000, and Gi0/1 is not forwarding traffic to Gi0/2, and vice versa, but we wand to do local switching between them. Configuration:

me3400(config)#vlan 1000
me3400(config-vlan)#uni-vlan community

to be continued …