Specifications

Configuring EAPS with STP

ExtremeWare XOS 11.0 Concepts Guide 191

NOTE

Choose EMITP encapsulation with tagged STP Carrier VLAN and 802.1D encapsulation with untagged

STP Carrier VLAN.

In this documentation, the VLAN carrying the STP BPDUs is named the STP Carrier VLAN. (Refer to

Chapter 12 for more information on STP.)

EAPS with STP Guidelines

Figure 16 shows multiple EAPS domains sharing a common link. This figure illustrates two EAPS

domains with S5 and S10 as common links. You must use STP in this configuration to prevent looping.

To configure STP on the multiple EAPS domains illustrated, you add the STP Carrier VLAN on all

nodes.

However, you enable STP only on S5 and S10, that is, on those switches connected to the common link.

The STP Domain includes only S5 and S10 in this configuration. All the other nodes in this illustration

(S1, S2, S3, S4, S6, S7, S8, and S9) are not enabled for STP, although all these nodes are running the STP

Carrier VLAN.

Finally, you add the STP Carrier VLAN as an EAPS protected VLAN only to the EAPS master nodes; in

this illustration, that is S1 and S9. The STP Carrier VLAN is not added as a protected VLAN to any

EAPS transit nodes.

Figure 16: Multiple EAPS domains sharing common link requires STP

When you are configuring EAPS plus STP, remember the following requirements:

• Add the STP Carrier VLAN as a protected VLAN only to the EAPS master node.

• Do not add the STP Carrier VLAN as a protected VLAN to any EAPS transit nodes in the ring.

NOTE

If you want to use spatial reuse technology in a network with EAPS and the STP, you must create a

separate STP Domain for each set of protected VLANs that forms a broadcast domain across multiple

EAPS rings. You must have a separate STP Domain per broadcast domain.

EW_091

Master

node

123

213

LHS ring

(STP root)

Master

node

RHS ring