User manual EXTREME NETWORKS SUMMIT 200

[. . . ] Summit 200 Series Switch Installation and User Guide Software Version 6. 2e. 2 Extreme Networks, Inc. 3585 Monroe Street Santa Clara, California 95051 (888) 257-3000 http://www. extremenetworks. com Published: June 2003 Part Number: 100149-00 Rev 01 ©2003 Extreme Networks, Inc. Extreme Networks and BlackDiamond are registered trademarks of Extreme Networks, Inc. in the United States and certain other jurisdictions. [. . . ] Figure 25: EAPS operation S4 S3 S5 S2 P S1 Direction of health-check message S6 S Secondary port is logically blocked Master node EW_071 If the ring is complete, the master node logically blocks all data traffic in the transmit and receive directions on the secondary port to prevent a loop. If the master node detects a break in the ring, it unblocks its secondary port and allows data traffic to be transmitted and received through it. 130 Summit 200 Series Switch Installation and User Guide Overview of the EAPS Protocol Fault Detection and Recovery EAPS fault detection on a ring is based on a single control VLAN per EAPS domain. This EAPS domain provides protection to one or more data-carrying VLANs called protected VLANs. The control VLAN is used only to send and receive EAPS messages; the protected VLANs carry the actual data traffic. As long as the ring is complete, the EAPS master node blocks the protected VLANs from accessing its secondary port. NOTE The control VLAN is not blocked. Messages sent on the control VLAN must be allowed into the switch for the master node to determine whether the ring is complete. Figure 26: EAPS fault detection and protection switching Break in ring S4 S4 sends "link down" message to master node S3 S3 sends "link down" message to master node S5 S2 P S1 S S6 Master node opens secondary port to allow traffic to pass Master node EW_072 A master node detects a ring fault in either of two ways: · Polling response · Trap message sent by a transit node Polling The master node transmits a health-check packet on the control VLAN at a user-configurable interval (see Figure 25). If the ring is complete, the master node will receive the health-check packet on its secondary port (the control VLAN is not blocked on the secondary port). When the master node receives the health-check packet, it resets its fail-period timer and continues normal operation. If the master node does not receive the health-check packet before the fail-period timer expires, it declares a "failed" state and opens its logically blocked secondary port on all the protected VLANs. Now, traffic can flow through the master's secondary port. The master node also flushes its forwarding Summit 200 Series Switch Installation and User Guide 131 Ethernet Automatic Protection Switching database (FDB) and sends a message on the control VLAN to all of its associated transit nodes to flush their forwarding databases as well, so that all of the switches can learn the new paths to Layer 2 end stations on the reconfigured ring topology. Trap Message Sent by a Transit Node When any transit node detects a loss of link connectivity on any of its ring ports, it immediately sends a "link down" message on the control VLAN using its good link to the master node. When the master node receives the "link down" message (see Figure 26), it immediately declares a "failed" state and performs the same steps described above; it unblocks its secondary port for access by the protected VLANs, flushes its FDB, and sends a "flush FDB" message to its associated transit nodes. Restoration Operations The master node continues sending health-check packets out its primary port even when the master node is operating in the failed state. As long as there is a break in the ring, the fail-period timer of the master node will continue to expire and the master node will remain in the failed state. When the broken link is restored, the master will receive its health-check packet back on its secondary port, and will once again declare the ring to be complete. It will logically block the protected VLANs on its secondary port, flush its FDB, and send a "flush FDB" message to its associated transit nodes. During the time between when the transit node detects that the link is operable again and when the master node detects that the ring is complete, the secondary port on the master node is still open and data could start traversing the transit node port that just came up. To prevent the possibility of a such a temporary loop, when the transit node detects that its failed link is up again, it will perform these steps: 1 For the port that just came up, put all the protected VLANs traversing that port into a temporary blocked state. 2 Remember which port has been temporarily blocked. When the master node receives its health-check packet back on its secondary port, and detects that the ring is once again complete, it sends a message to all its associated transit nodes to flush their forwarding databases. When the transit nodes receive the message to flush their forwarding databases, they perform these steps: 1 Flush their forwarding databases on the protected VLANs. 2 If the port state is set to Preforwarding, unblock all the previously blocked protected VLANs for the port. 132 Summit 200 Series Switch Installation and User Guide Summit 200 Series Switches in Multi-ring Topologies Summit 200 Series Switches in Multi-ring Topologies Figure 27 shows how a data VLAN could span two rings having two interconnecting switches in common. [. . . ] The show debug-tracing command can be applied to one or all VLANs, as follows: show debug-tracing {vlan <name>} The debug commands should only be used under the guidance of Extreme Networks technical personnel. TOP Command The top command is a utility that indicates CPU utilization by process. Contacting Extreme Technical Support If you have a network issue that you are unable to resolve, contact Extreme Networks technical support. Extreme Networks maintains several Technical Assistance Centers (TACs) around the world to answer networking questions and resolve network problems. You can contact technical support by phone at: · (800) 998-2408 · (408) 579-2826 or by email at: · support@extremenetworks. com You can also visit the support website at: · http://www. extremenetworks. com/extreme/support/techsupport. asp to download software updates (requires a service contract) and documentation. Summit 200 Series Switch Installation and User Guide 237 Troubleshooting 238 Summit 200 Series Switch Installation and User Guide Index Numerics 802. 1p configuration commands (table) 149 autonegotiation autopolarity detection feature, Ethernet ports 77 78 A access control lists adding configuration commands (table) deleting description examples ICMP filter example permit-established example permit-established keyword verifying settings access levels access masks adding deleting access policies, description access profiles, reverse mask accounts creating deleting viewing adding access lists access masks rate limits Address Resolution Protocol. See ARP admin account Advanced Edge functionality aging entries, FDB alarm actions Alarms, RMON area 0, OSPF areas, OSPF ARP clearing entries communicating with devices outside subnet configuring proxy ARP incapable device proxy ARP between subnets proxy ARP, description of responding to ARP requests table, displaying 105 107 106 101 110 113 110 104 106 46 105 106 101 115 48 49 49 105 105 105 47 38 97 167 166 198 197 189 181 181 181 181 180 181 183 B backbone area, OSPF blackhole entries, FDB boot option commands (table) BOOTP and UDP-Forwarding relay, configuring using BootROM menu, accessing prompt upgrading BPDU tunneling 198 98 236 190 190 54 235 235 235 170 C cable types and distances certification marks Summit 200-24 switch Summit 200-48 switch CLI command history command shortcuts line-editing keys named components numerical ranges, Summit 200 series switch symbols syntax helper using command history shortcuts syntax, understanding Command-Line Interface. [. . . ]