Dell Force10 S25N-S50N FTOS Configuration Guide FTOS 8.4.2.7 E-Series TeraScal - Page 952

www.dell.com | support.dell.com VLAN 100 In at the access point of a VLAN-stacking network, service providers add a VLAN tag, the S-Tag, to each frame before the 802.1Q tag. From this point, the frame is double-tagged. The service provider uses the S-Tag, to forward the frame traffic across its network. At the egress edge, the provider removes the S-Tag, so that the customer receives the frame in its original condition (Figure 46-1). Figure 46-1. VLAN Stacking in a Service Provider Network TPID PCP (0x9100) DEI VID TPID PCP (VLAN 300) (0x8100) CFI VID (0) (VLAN Red) tagged 100 IN 100 VLAN VLAN 100 tagged 100 trunk port access port VLAN 200 VLAN 300 TERNET SERVICE PROVIDERw/ VLAN STACKING VLAN 100 Important Points to Remember • Interfaces that are members of the Default VLAN and are configured as VLAN-Stack access or trunk ports do not switch untagged traffic. To switch traffic, these interfaces must be added to a non-default VLAN-Stack-enabled VLAN. • Dell Force10 cautions against using the same MAC address on different customer VLANs, on the same VLAN-Stack VLAN. • You can ping across a trunk port only if both systems on the link are an E-Series. You cannot ping across the link if one or both of the systems is a C-Series or S-Series. • This limitation becomes relevant if you enable the port as a multi-purpose port (carrying single-tagged and double-tagged traffic). 952 | Service Provider Bridging