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... P T E R 6 C H A P T E R 78-15486-01 Configuring Gigabit Ethernet Switching 5-1 Understanding How Gigabit Ethernet Works 5-1 Understanding How Gigabit Ethernet Flow Control Works 5-1 Understanding How Port ... Tree Port Cost 6-8 Setting the EtherChannel Spanning Tree Port VLAN Cost 6-9 Removing an EtherChannel Bundle 6-9 Displaying EtherChannel Configuration Information 6-10 Displaying EtherChannel Traffic Statistics 6-11 Displaying EtherChannel PAgP Statistics 6-12 EtherChannel Configuration Examples 6-12 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration...
... P T E R 6 C H A P T E R 78-15486-01 Configuring Gigabit Ethernet Switching 5-1 Understanding How Gigabit Ethernet Works 5-1 Understanding How Gigabit Ethernet Flow Control Works 5-1 Understanding How Port ... Tree Port Cost 6-8 Setting the EtherChannel Spanning Tree Port VLAN Cost 6-9 Removing an EtherChannel Bundle 6-9 Displaying EtherChannel Configuration Information 6-10 Displaying EtherChannel Traffic Statistics 6-11 Displaying EtherChannel PAgP Statistics 6-12 EtherChannel Configuration Examples 6-12 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration...
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... T E R Configuring Spanning Tree 7-1 Understanding How STPs Work 7-2 Understanding How a Topology Is Created 7-2 Understanding How a Switch or Port Becomes the Root Switch or Root Port 7-3 Understanding BPDUs 7-4 Calculating and Assigning Port Costs 7-4 Understanding Spanning Tree Port States 7-5 Understanding How PVST+ and MISTP Modes Work 7-11 PVST+ Mode 7-12 Rapid PVST...7-16 MST-to-SST Interoperability 7-17 Common Spanning Tree 7-18 MST Instances 7-18 MST Configuration 7-18 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 vi 78-15486-01
... T E R Configuring Spanning Tree 7-1 Understanding How STPs Work 7-2 Understanding How a Topology Is Created 7-2 Understanding How a Switch or Port Becomes the Root Switch or Root Port 7-3 Understanding BPDUs 7-4 Calculating and Assigning Port Costs 7-4 Understanding Spanning Tree Port States 7-5 Understanding How PVST+ and MISTP Modes Work 7-11 PVST+ Mode 7-12 Rapid PVST...7-16 MST-to-SST Interoperability 7-17 Common Spanning Tree 7-18 MST Instances 7-18 MST Configuration 7-18 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 vi 78-15486-01
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...Default PVST+ Configuration 7-23 Setting the PVST+ Bridge ID Priority 7-23 Configuring the PVST+ Port Cost 7-25 Configuring PVST+ Port Priority 7-25 Configuring the PVST+ Default Port Cost Mode 7-26 Configuring the PVST+ Port VLAN Cost 7-26 Configuring the PVST+ Port VLAN Priority 7-27 Disabling the PVST+ Mode on a VLAN ... Tree BPDU Skewing 7-57 Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard 8-1 Understanding How PortFast Works 8-1 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 vii
...Default PVST+ Configuration 7-23 Setting the PVST+ Bridge ID Priority 7-23 Configuring the PVST+ Port Cost 7-25 Configuring PVST+ Port Priority 7-25 Configuring the PVST+ Default Port Cost Mode 7-26 Configuring the PVST+ Port VLAN Cost 7-26 Configuring the PVST+ Port VLAN Priority 7-27 Disabling the PVST+ Mode on a VLAN ... Tree BPDU Skewing 7-57 Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard 8-1 Understanding How PortFast Works 8-1 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 vii
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.../100-Mbps Fast Ethernet ports • Port cost of 19 for 100-Mbps Fast Ethernet ports Disabled on all Fast Ethernet ports (auto mode) Configuring Ethernet and Fast Ethernet Ports These sections describe how to configure Ethernet and Fast Ethernet switching ports on the Catalyst enterprise LAN switches: • Setting Ethernet and Fast Ethernet...
.../100-Mbps Fast Ethernet ports • Port cost of 19 for 100-Mbps Fast Ethernet ports Disabled on all Fast Ethernet ports (auto mode) Configuring Ethernet and Fast Ethernet Ports These sections describe how to configure Ethernet and Fast Ethernet switching ports on the Catalyst enterprise LAN switches: • Setting Ethernet and Fast Ethernet...
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...are enabled Port name None Port priority Normal Duplex mode Full duplex Flow control • Oversubscribed Gigabit Ethernet ports (ports 3-18 on WS-X4418-GB): Flow control set to desired for receive (Rx) and on for transmit (Tx) • All others: Flow ...for transmit (Tx) Port negotiation Enabled Spanning Tree Protocol Enabled for VLAN 1 Native VLAN VLAN 1 Spanning tree port cost 4 Gigabit EtherChannel Disabled on all Gigabit Ethernet ports (auto mode) Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 5-6 78-15486-01
...are enabled Port name None Port priority Normal Duplex mode Full duplex Flow control • Oversubscribed Gigabit Ethernet ports (ports 3-18 on WS-X4418-GB): Flow control set to desired for receive (Rx) and on for transmit (Tx) • All others: Flow ...for transmit (Tx) Port negotiation Enabled Spanning Tree Protocol Enabled for VLAN 1 Native VLAN VLAN 1 Spanning tree port cost 4 Gigabit EtherChannel Disabled on all Gigabit Ethernet ports (auto mode) Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 5-6 78-15486-01
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...problems. Note Except where noted, these guidelines apply to full duplex. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-3 Note Switches can form an EtherChannel as long as "not connected" using the show port command... and as they are otherwise compatibly configured. The port is suppressed. Setting different port path costs does ...
...problems. Note Except where noted, these guidelines apply to full duplex. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-3 Note Switches can form an EtherChannel as long as "not connected" using the show port command... and as they are otherwise compatibly configured. The port is suppressed. Setting different port path costs does ...
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...will not form if protocol filtering is set differently on the ports. • Cisco Discovery Protocol (CDP) runs on the physical port even after the port is not...Note With software release 6.3(1) and later releases, a PAgP-configured EtherChannel is enabled. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-4 78-15486-01 In software releases prior to 6.3(1),... SPAN destination port. • An EtherChannel will not form with different VLAN costs or VLAN configurations cannot form a channel. Do not enable the port security feature...
...will not form if protocol filtering is set differently on the ports. • Cisco Discovery Protocol (CDP) runs on the physical port even after the port is not...Note With software release 6.3(1) and later releases, a PAgP-configured EtherChannel is enabled. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-4 78-15486-01 In software releases prior to 6.3(1),... SPAN destination port. • An EtherChannel will not form with different VLAN costs or VLAN configurations cannot form a channel. Do not enable the port security feature...
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...show channel group command to which the EtherChannel belongs. The ID can form a single EtherChannel. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-6 78-15486-01 You can define an EtherChannel administrative group without... • Defining an EtherChannel Administrative Group, page 6-7 • Setting the EtherChannel Spanning Tree Port Cost, page 6-8 • Setting the EtherChannel Spanning Tree Port VLAN Cost, page 6-9 • Removing an EtherChannel Bundle, page 6-9 • Displaying EtherChannel Configuration Information, page...
...show channel group command to which the EtherChannel belongs. The ID can form a single EtherChannel. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-6 78-15486-01 You can define an EtherChannel administrative group without... • Defining an EtherChannel Administrative Group, page 6-7 • Setting the EtherChannel Spanning Tree Port Cost, page 6-8 • Setting the EtherChannel Spanning Tree Port VLAN Cost, page 6-9 • Removing an EtherChannel Bundle, page 6-9 • Displaying EtherChannel Configuration Information, page...
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...ID Platform group 50 3/5 50 3/6 Console> (enable) Setting the EtherChannel Spanning Tree Port Cost To set the spanning tree port cost for an EtherChannel, perform this task in privileged mode: Step 1 Step 2 Task Define ...cost for channel ID 768: Console> (enable) show channel group 20 Admin Port Status Channel Channel group Mode id 20 1/1 notconnect on 768 20 1/2 connected on 768 Admin Port Device-ID Port-ID Platform group 20 1/1 20 1/2 066510644(cat26-lnf(NET25)) 2/1 WS-C6009 Console> (enable) Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches...
...ID Platform group 50 3/5 50 3/6 Console> (enable) Setting the EtherChannel Spanning Tree Port Cost To set the spanning tree port cost for an EtherChannel, perform this task in privileged mode: Step 1 Step 2 Task Define ...cost for channel ID 768: Console> (enable) show channel group 20 Admin Port Status Channel Channel group Mode id 20 1/1 notconnect on 768 20 1/2 connected on 768 Admin Port Device-ID Port-ID Platform group 20 1/1 20 1/2 066510644(cat26-lnf(NET25)) 2/1 WS-C6009 Console> (enable) Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches...
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..., Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-9 Console> (enable) Removing an EtherChannel Bundle To return a Fast EtherChannel or Gigabit EtherChannel bundle to its default configuration, perform this task in privileged mode: Step 1 Step 2 Task Command Return a channel to its default configuration (you want to set the spanning tree port VLAN cost for...
..., Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-9 Console> (enable) Removing an EtherChannel Bundle To return a Fast EtherChannel or Gigabit EtherChannel bundle to its default configuration, perform this task in privileged mode: Step 1 Step 2 Task Command Return a channel to its default configuration (you want to set the spanning tree port VLAN cost for...
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...; Specifying the Channel Path Cost, page 6-21 • Specifying the Channel VLAN Cost, page 6-21 • Clearing LACP Statistics, page 6-21 • Displaying EtherChannel Traffic Utilization, page 6-21 • Disabling an EtherChannel, page 6-22 • Displaying Spanning Tree-Related Information for all modules. 6-18 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release...
...; Specifying the Channel Path Cost, page 6-21 • Specifying the Channel VLAN Cost, page 6-21 • Clearing LACP Statistics, page 6-21 • Displaying EtherChannel Traffic Utilization, page 6-21 • Disabling an EtherChannel, page 6-22 • Displaying Spanning Tree-Related Information for all modules. 6-18 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release...
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... (enable) 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-21 See the "Setting the EtherChannel Spanning Tree Port VLAN Cost" section on page 6-8. Specifying the Channel VLAN Cost You can specify the channel path cost by using a global command ... traffic This example shows how to display traffic utilization on . For more information, see the "Setting the EtherChannel Spanning Tree Port Cost" section on page 6-9 for ports 4/1 and 4/6 is unchanged. Console> (enable) set port lacp-channel 4/1,4/6 mode on Port...
... (enable) 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 6-21 See the "Setting the EtherChannel Spanning Tree Port VLAN Cost" section on page 6-8. Specifying the Channel VLAN Cost You can specify the channel path cost by using a global command ... traffic This example shows how to display traffic utilization on . For more information, see the "Setting the EtherChannel Spanning Tree Port Cost" section on page 6-9 for ports 4/1 and 4/6 is unchanged. Console> (enable) set port lacp-channel 4/1,4/6 mode on Port...
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... EtherChannels, perform this task for EtherChannels. Command show spantree mod/port These examples show spantree 4/7-8 Port Vlan Port-State Cost Priority Portfast Channel_id 4/7-8 1 blocking 3 32 disabled 770 Console> 6-22 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01 Console> (enable) Displaying Spanning Tree-Related Information for EtherChannels You can...
... EtherChannels, perform this task for EtherChannels. Command show spantree mod/port These examples show spantree 4/7-8 Port Vlan Port-State Cost Priority Portfast Channel_id 4/7-8 1 blocking 3 32 disabled 770 Console> 6-22 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01 Console> (enable) Displaying Spanning Tree-Related Information for EtherChannels You can...
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... if spanning tree costs change, the spanning tree algorithm reconfigures the spanning tree topology and reestablishes the link by placing redundant switch ports in an ...exist between stations can cause loops in a network while preventing undesirable loops. The Cisco proprietary spanning tree protocols, PVST+ and MISTP, are eliminated by activating a standby...; A unique root switch is elected for information about other switches in the network through the network. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-2...
... if spanning tree costs change, the spanning tree algorithm reconfigures the spanning tree topology and reestablishes the link by placing redundant switch ports in an ...exist between stations can cause loops in a network while preventing undesirable loops. The Cisco proprietary spanning tree protocols, PVST+ and MISTP, are eliminated by activating a standby...; A unique root switch is elected for information about other switches in the network through the network. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-2...
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..., connecting higher-speed links to a port that is, lowering the priority number) on Switch B is associated with each switch • The path cost to make the selected switch the root switch. However, due to a lower value than the fiber-optic port, the UTP port ... The following three things determine the topology of an active switched network: • The unique switch identifier (MAC address of the switch) that of the fiber-optic port. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-3 A spanning tree protocol ...
..., connecting higher-speed links to a port that is, lowering the priority number) on Switch B is associated with each switch • The path cost to make the selected switch the root switch. However, due to a lower value than the fiber-optic port, the UTP port ... The following three things determine the topology of an active switched network: • The unique switch identifier (MAC address of the switch) that of the fiber-optic port. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-3 A spanning tree protocol ...
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... tree topology. This is the switch that the shortest (lowest cost) distance to calculate the port cost unless you can also manually assign port costs between 1-65535. For more information on setting the default cost mode, see the "Configuring the PVST+ Default Port Cost Mode" section on bandwidth. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release...
... tree topology. This is the switch that the shortest (lowest cost) distance to calculate the port cost unless you can also manually assign port costs between 1-65535. For more information on setting the default cost mode, see the "Configuring the PVST+ Default Port Cost Mode" section on bandwidth. Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release...
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... port cost values to each port using a formula that is based on a switch using the old topology. You can start forwarding frames. Recalculation may not be desirable, especially if the added or removed link is to divide the bandwidth of these states: • Blocking 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software...
... port cost values to each port using a formula that is based on a switch using the old topology. You can start forwarding frames. Recalculation may not be desirable, especially if the added or removed link is to divide the bandwidth of these states: • Blocking 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software...
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... sent in the neighboring SST regions because the root identifier and root cost are the same for root identifiers and root path costs are optional. MST Configuration MST configuration has three parts as a single SST or pseudobridge. In a Catalyst 4500 series switch running PVST+, the VLAN 1 spanning tree corresponds to the configuration. Pseudobridges operate...
... sent in the neighboring SST regions because the root identifier and root cost are the same for root identifiers and root path costs are optional. MST Configuration MST configuration has three parts as a single SST or pseudobridge. In a Catalyst 4500 series switch running PVST+, the VLAN 1 spanning tree corresponds to the configuration. Pseudobridges operate...
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... have a bridge. To establish rapid connectivity after a failure, you enable PortFast on that lead to -point links. 7-20 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01 Otherwise, the port requires twice the forward delay time to start forwarding as soon ...configure the ports that all full-duplex links as the link is the bridge with the lowest bridge identifier and the least path cost to -point links. You must explicitly configure ports to the hosts and routers as edge, that can avoid explicit configuration by ...
... have a bridge. To establish rapid connectivity after a failure, you enable PortFast on that lead to -point links. 7-20 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01 Otherwise, the port requires twice the forward delay time to start forwarding as soon ...configure the ports that all full-duplex links as the link is the bridge with the lowest bridge identifier and the least path cost to -point links. You must explicitly configure ports to the hosts and routers as edge, that can avoid explicit configuration by ...
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... Hops 20 1/0 Bridge ID MAC ADDR Bridge ID Priority 00-10-7b-bb-2f-00 8195 (bridge priority:8192, sys ID ext:3) Port State Role Cost Prio Type 6/1 forwarding BDRY 10000 30 P2P, Boundary(PVST) 6/2 blocking BDRY 20000 32 P2P, Boundary(PVST) If you configure MST... a topology where you enable loop guard on its designated ports, root guard sets the port to interact with a slower CPU running MST. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-21
... Hops 20 1/0 Bridge ID MAC ADDR Bridge ID Priority 00-10-7b-bb-2f-00 8195 (bridge priority:8192, sys ID ext:3) Port State Role Cost Prio Type 6/1 forwarding BDRY 10000 30 P2P, Boundary(PVST) 6/2 blocking BDRY 20000 32 P2P, Boundary(PVST) If you configure MST... a topology where you enable loop guard on its designated ports, root guard sets the port to interact with a slower CPU running MST. 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 7-21