296 BigIron RX Series Configuration Guide53-1001810-01Configuring super aggregated VLANs11• Enable VLAN aggregation. This support allows the core device to add an additional tag toeach Ethernet frame that contains a VLAN packet from the edge device. The additional tagidentifies the aggregate VLAN (the path). However, the additional tag can cause the frameto be longer than the maximum supported frame size. The larger frame support allowsEthernet frames up to 1530 bytes long.NOTEEnable the VLAN aggregation option only on the core devices.• Configure a VLAN tag type (tag ID) that is different than the tag type used on the edgedevices. If you use the default tag type (8100) on the edge devices, set the tag type on thecore devices to another value, such as 9100. The tag type must be the same on all thecore devices. The edge devices also must have the same tag type but the type must bedifferent from the tag type on the core devices.NOTEYou can enable the Spanning Tree Protocol (STP) on the edge devices or the core devices, butnot both. If you enable STP on the edge devices and the core devices, STP will prevent clienttraffic from travelling through the core to the other side.For example, to configure the aggregated VLANs on device C in Figure 24 on page 294, enterthe following commands.BigIron RX(config)# tag-type 9100BigIron RX(config)# aggregated-vlanBigIron RX(config)# vlan 101BigIron RX(config-vlan-101)# tagged ethernet 4/1BigIron RX(config-vlan-101)# untagged ethernet 3/1BigIron RX(config-vlan-101)# exitBigIron RX(config)# vlan 102BigIron RX(config-vlan-102)# tagged ethernet 4/1BigIron RX(config-vlan-102)# untagged ethernet 3/2BigIron RX(config-vlan-102)# exitBigIron RX(config)# write memorySyntax: [no] tag-type Syntax: [no] aggregated-vlanThe parameter specifies the tag type. It can be a hexadecimal value from 0 – ffff. Thedefault is 8100.Complete CLI examplesThe following sections show all the Aggregated VLAN configuration commands on the devices inFigure 24 on page 294.NOTEIn these examples, the configurations of the edge devices (A, B, E, and F) are identical. Theconfigurations of the core devices (C and D) also are identical. The aggregated VLAN configurationsof the edge and core devices on one side must be symmetrical (in fact, a mirror image) to theconfigurations of the devices on the other side. For simplicity, the example in Figure 24 on page 294is symmetrical in terms of the port numbers. This allows the configurations for both sides of the linkto be the same. If your configuration does not use symmetrically arranged port numbers, theconfigurations should not be identical but must use the correct port numbers.
