Layer 2 Protocol Tunneling Support for VxLAN Tenant VLANs

Layer 2 protocol tunneling (L2PT) is achieved by encapsulating the PDUs at the ingress PE device before transmitting them over the service provider network. The encapsulation prevents the PDUs from being processed by the switches in the SP network. At the egress PE device, the encapsulated packets are de-encapsulated, and transmitted to the CE device.

An added encapsulation is used for different types of networks:

VXLAN – The DA MAC of the Layer 2 PDU is changed to L2PT DA MAC at the ingress remote tunnel end-point (RTEP). The modified packet is then encapsulated into a VXLAN packet and sent over the network. At the egress RTEP, the packet is lifted to the CPU for L2PT processing. After VXLAN decapsulation, the DA MAC is changed from L2PT MAC to the protocol MAC and is sent on the access ports of the tenant VLAN.

An operator can specify a value of CoS for the tunneled PDUs. This can be useful since some L2 protocols may have a higher priority than others (for example, may be considered higher priority than ). If a CoS value is specified for a protocol for which tunneling is enabled, the switch will transmit the encapsulated PDUs for that protocol with the operator specified CoS towards the network. An added CoS value specified by the operator is transmitted on the SP network:

VXLAN – The CoS value configured on the profile attached to the access port is written to the PRI bits of the outer VLAN header of the VXLAN encapsulated frames before transmitting them to other RTEPs.

As VXLAN tunneled packets cross L3 boundaries in the underlay network, the CoS can get lost when traversing L3 boundaries. An operator may choose to configure a Differentiated Services Code Point (DSCP) that needs to be set in the outer IP header of the encapsulated packets. If the packet encapsulated into the VXLAN tunnel is an IP packet, the DSCP from inner IP header is typically copied to DSCP of the outer IP header. A configuration option is provided to overwrite this outer DSCP value. In case of L2 protocols (which do not have an inner DSCP), the configured DSCP value is set in the outer IP header.

Supported Platforms

This command is supported on the ExtremeSwitching X770, X670-G2, X465, X590, X690, X695, X870, 5520 series switches, and stacks with X465, X590, X670-G2, X690, X770, X695, X870, 5520 slots only.

New CLI Commands

clear l2pt counters {[vlan] vlan_name {{vxlan {vr vr_name} rtep rtep_ipv4}}}

configure [[{vlan vlan_name] [vxlan {vr vr_name} rtep rtep_ipv4]] l2pt profile [none | profile_name]

show [[{vlan} vlan_name] {{vxlan {vr vr_name} rtep rtep_ipv4}}] l2pt {detail}