BROCADE IP PRIMER

49FLinkPower49FLinkPower50F50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48Console1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 4849FLinkPower49FLinkPower50F50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48Console1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 4849FLinkPower50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 4849FLinkPower50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 4849FLinkPower49FLinkPower50F50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48Console1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48IEEE 802.1d (Spanning Tree Protocol)But the switch is no dummy. It will automatically use standard STP (not FastPort Span) if it detects any of the following disqualifying conditions on a givenport:• The port is an 802.1q tagged member of a VLAN• The port is a member of a trunk group• The switch sees more than one MAC address coming from that port; thisindicates that there's a hub (or another switch) upstream, and that couldmean a possible Layer 2 loop• The switch sees an STP BPDU coming in on the port; this would indicatethat there's another switch upstream, so there would be a potential Layer2 loopIf, for whatever reason, you'd like to disable this feature, you would do so in theGlobal config:Switch(config)#no fast port-spanYou can re-enable it, as well. Also, if you like, you can enable it switch-wide, butdisable it on certain ports:Switch(config)#fast port-span exclude e 48This will keep Fast Port Span enabled on all of your switch ports except e 48.When Fast Port Span is disabled, it will use the standard STP timers.This is fine if you're dealing with workstations, but what about other switches?Well, let's say you have an edge switch that represents a dead end of the network.You've got two links (not trunked) going from this switch to the coreswitch.fastuplink-spanYou know that this switch represents an end to your network. There are no furtheruplinks to any other switches. Well, then, let's configure the core switchports to use Fast Uplink Span. Notice that this is done in the Global config:Switch(config)#fast uplink-span e 15 to 16Brocade IP Primer 203