TRILL Interoperability with Layer 2 Protocols

TRILL Access VLANs are compatible with L2 switching protocols such as STP, EAPS, and ERPS for some topologies. The CLI does prevent incompatible features from being configured on a TRILL interface or VLAN, but does not prevent all unsupported networking configurations from being configured. If a range of VLAN tags is specified and an incompatible feature is detected on a VLAN, the command does not abort and continues onto the next sequential VLAN tag. Reference verified solutions are also available from Extreme. Please contact your Extreme Sales Representative for additional information.

The following protocol features cannot be configured on a TRILL Network VLAN.

IP Forwarding
IP Routing Protocols
IP Multicast Protocols
MPLS
ESRP
Ring Protocols (i.e., EAPS, ERPS)
MLAG
Private VLANs
VLAN Translation
VLAN Aggregation
VMANs
VPLS
VRRP
STP
Customer Edge Ports (CEP)
Multicast Snooping
Any type of tunnel (e.g, GRE, IPv6-to-IPv4, IPv6-in-IPv4)

In general, if an L2 protocol (STP, EAPS, ERPS, etc.) is enabled on the TRILL access port, then the L2 protocol PDUs will not be tunneled through the TRILL network, but instead processed locally at the ingress Rbridge. If a PDU is received for a protocol that is not enabled then it will be treated like data and therefore tunneled through the TRILL network. STP is an exception as the TRILL protocol requires the STP BPDU to always be processed at the access regardless of the STP admin state.

Enabling TRILL and MLAG on the same switch may cause temporary flooding. This limitation is present even if MLAG VLANs and TRILL access/network VLANs are different.

LACP is another example that will always be processed and never tunneled as it has local(LAG) significance only.

Protocols not supported by ExtremeXOS will be tunneled (just like a supported, but disabled protocol). Examples: VTP is a protocol that ExtremeXOS does not support in 15.4.1.

Protocols such as STP, EAPS, ERPS, and ELRP can be configured on TRILL Access VLANs and will function correctly in some network configurations. Although not specifically designed to support them, VMAN packets can be carried over a TRILL network provided they are treated as basic Ethernet tagged packets (packets use an ethertype of 0x8100 instead of 0x88a8).

Published March 2020prev | next

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