【Lab Objectives】
1. Master the configuration methods of the Cisco-proprietary link aggregation protocol of PAgP.
2. Master the differences between the Layer2 PAgP configuration and the Layer3 PAgP configuration.
3. PAgP is a Cisco-proprietary link aggregation protocol.
【Lab Topology】
【Lab Steps】
1.This lab uses two Cisco Catalyst 3750 Series Switches and connects the cables of the appropriate switches according to the topology.
2. It is recommended to set the interfaces Fa1/0/1 – 22 in shutdown status in order to assure the lab of success.
3. Check the STP information on SW1 and SW2
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SW1#show spanning-tree
VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address 0014.a8e2.9880 Cost 19 Port 25 (FastEthernet1/0/23) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 0014.a8f1.9880 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300
Interface Role Sts Cost Prio.Nbr Type —————- —- — ——— ——– ——————————– Fa1/0/23 Root FWD 19 128.25 P2p Fa1/0/24 Altn BLK 19 128.26 P2p
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4. Although STP can avoid loops in the network, it can’t make full use of the bandwidth of the redundant links. The link aggregation protocol PAgP can be used to solve the link bandwidth problems.
5. The configurations on SW1 and SW2 are as follows:
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SW1(config)#interface range fastEthernet 1/0/23 – 24 SW1(config-if-range)#switchport SW1(config-if-range)#channel-protocol pagp SW1(config-if-range)#channel-group 1 mode desirable Creating a port-channel interface Port-channel 1
SW1(config-if-range)#exit SW1(config)#exit |
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SW2(config)#interface range fastEthernet 1/0/23 – 24 SW2(config-if-range)#sw SW2(config-if-range)#switchport SW1(config-if-range)#channel-protocol pagp SW2(config-if-range)#channel-group 1 mode auto Creating a port-channel interface Port-channel 1
SW2(config-if-range)#exit SW2(config)#exit |
6. The interface in the Descirable mode of PAgP will actively enter the negotiation status, while in the Auto mode it will passively enter the negotiation status.
7. After configuring the two switches properly, IOS will show the following information in the process of configuration.
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00:32:28: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/23, changed state to down 00:32:28: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/24, changed state to down
00:32:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/23, changed state to up 00:32:38: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/24, changed state to up
0:37:18: %LINK-3-UPDOWN: Interface Port-channel1, changed state to up 00:37:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1, changed state to up |
8. Check the aggregation information on the interface of SW1.
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SW1#show interfaces fastEthernet 1/0/23 etherchannel Port state = Up Mstr In-Bndl Channel group = 1 Mode = Desirable-Sl Gcchange = 0 Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1 Port index = 0 Load = 0x00 Protocol = PAgP
Flags: S – Device is sending Slow hello. C – Device is in Consistent state. A – Device is in Auto mode. P – Device learns on physical port. d – PAgP is down. Timers: H – Hello timer is running. Q – Quit timer is running. S – Switching timer is running. I – Interface timer is running.
Local information: Hello Partner PAgP Learning Group Port Flags State Timers Interval Count Priority Method Ifindex Fa1/0/23 SC U6/S7 H 30s 1 128 Any 5001
Partner’s information:
Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Fa1/0/23 SW2 0014.a8e2.9880 Fa1/0/23 20s SAC 10001
Age of the port in the current state: 00d:00h:06m:53s
SW1# |
9. Use the show etherchannel port-channel command to check the aggregation group information
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SW1#show etherchannel port-channel Channel-group listing: ———————-
Group: 1 ———- Port-channels in the group: —————————
Port-channel: Po1 ————
Age of the Port-channel = 00d:00h:15m:37s Logical slot/port = 10/1 Number of ports = 2 GC = 0x00010001 HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = PAgP
Ports in the Port-channel:
Index Load Port EC state No of bits ——+——+——+——————+———– 0 00 Fa1/0/23 Desirable-Sl 0 0 00 Fa1/0/24 Desirable-Sl 0
Time since last port bundled: 00d:00h:10m:27s Fa1/0/24
SW1# |
10. Check the summary information of the aggregation link.
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SW1#show etherchannel summary Flags: D – down P – in port-channel I – stand-alone s – suspended H – Hot-standby (LACP only) R – Layer3 S – Layer2 U – in use f – failed to allocate aggregator u – unsuitable for bundling w – waiting to be aggregated d – default port
Number of channel-groups in use: 1 Number of aggregators: 1
Group Port-channel Protocol Ports ——+————-+———–+———————————————– 1 Po1(SU) PAgP Fa1/0/23(P) Fa1/0/24(P)
SW1# |
11. Check the spanning-tree information.
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SW1#show spanning-tree
………
Interface Role Sts Cost Prio.Nbr Type —————- —- — ——— ——– ——————————– Po1 Root FWD 12 128.616 P2p
SW1# |
12. Configure IP addresses of VLAN1 on SW1 and SW2, test the tolerance of the aggregation link.
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SW1(config)#interface vlan 1 SW1(config-if)#ip address 192.168.1.1 255.255.255.0 SW1(config-if)#no shutdown SW1(config-if)#exit |
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SW2(config)#interface vlan 1 SW2(config-if)#ip address 192.168.1.2 255.255.255.0 SW2(config-if)#no shutdown SW2(config-if)#exit |
13. Use the Ping command on R1 to test the connectivity between the two switches.
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SW2#ping 192.168.1.1
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms SW2# |
14. Use the extended ping command on SW2 to send ICMP data packets to SW1 continuously to test the redundant tolerance of the aggregation ports.
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SW2#ping Protocol [ip]: Target IP address: 192.168.1.1 Repeat count [5]: 1000000 Datagram size [100]: Timeout in seconds [2]: Extended commands [n]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 1000000, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
15. Manually shutdown the interface Fastethernet 1/0/24 or Fastethernet 1/0/24 of aggregation group on SW1 and observe the ping feedback information on SW2. It is found that the Ping data packets will not be interrupted, which indicates that the link aggregation can effectively avoid instability of the topology of the single link and solve the problems that link bandwidth can be used completely and achieve load balancing due to spanning tree under redundant link.
16. The previous configuration is of the Layer2 PAgP link aggregation, the following configuration will show us how to configure the Layer3 PAgP link aggregation.
17. Delete the previous Layer2 PAgP configuration.
18. Configure SW1 and SW2 as follows.
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SW1(config)#interface port-channel 1 SW1(config-if)#no switchport SW1(config-if)#ip address 192.168.1.1 255.255.255.0 SW1(config-if)#no shutdown SW1(config-if)#exit SW1(config)# SW1(config)# SW1(config)#interface range fastEthernet 1/0/23 – 24 SW1(config-if-range)#no switchport SW1(config-if-range)#channel-protocol pagp SW1(config-if-range)#channel-group 1 mode desirable SW1(config-if-range)#exit SW1(config)#exit SW1# 00:12:15: %EC-5-L3DONTBNDL1: Fa1/0/23 suspended: PAgP not enabled on the remote port. 00:12:16: %EC-5-L3DONTBNDL1: Fa1/0/24 suspended: PAgP not enabled on the remote port. |
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SW2(config)#interface port-channel 1 SW2(config-if)#no switchport SW2(config-if)#ip address 192.168.1.2 255.255.255.0 SW2(config-if)#no shutdown SW2(config-if)#exit SW2(config)# SW2(config)#interface range fastEthernet 1/0/23 – 24 SW2(config-if-range)#no switchport SW2(config-if-range)#channel-protocol pagp SW2(config-if-range)#channel-group 1 mode desirable SW2(config)#exit SW2# 00:20:02: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/23, changed state to up 00:20:02: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/24, changed state to up 00:20:03: %LINK-3-UPDOWN: Interface Port-channel1, changed state to up 00:20:04: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1, changed state to up |
17. Check the information of the aggregation links
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SW2#show etherchannel summary Flags: D – down P – in port-channel I – stand-alone s – suspended H – Hot-standby (LACP only) R – Layer3 S – Layer2 U – in use f – failed to allocate aggregator u – unsuitable for bundling w – waiting to be aggregated d – default port
Number of channel-groups in use: 1 Number of aggregators: 1
Group Port-channel Protocol Ports ——+————-+———–+———————————————– 1 Po1(RU) PAgP Fa1/0/23(P) Fa1/0/24(P)
SW2# |
18. Use the Ping command to test
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SW2#ping 192.168.1.1
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds: .!!!! Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/1 ms |
19. Use step14 and step15 to test the tolerance of the Layer3 PAgP aggregation link. The detailed steps will not be listed.
20. End.
Hope to helpful for you!
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Peter Quinn