make sure all the cabling are fine and working, show CDP should be able to show all it's neighbor
set all the connected port above to be a trunking port
ex using int range command on CORE1 to set trunk on int Gi1/1 until Gi1/3
CORE1(config)#interface range gigabitEthernet 1/1 - 3
CORE1(config-if-range)#switchport trunk encapsulation dot1q
CORE1(config-if-range)#switchport mode trunk
configure etherchannel between CORE1 and CORE2
interface GigabitEthernet1/1 (same for Gi1/2)
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
channel-protocol lacp
channel-group 64 mode active
end
this will automatically create etherchannel, Po64, make sure all the attribute in physical port applied the same to the port channel
interface Port-channel64
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
end
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
end
*once you start your switch, check the name, if 'router>' then all ports are layer3 port and by default is administratively shutdown, change it to switchport (layer2)
*if start with 'switch>', then it shouldn't be any problem
make sure you configure this on all ports above, next is creating management VLAN interface, we'll use VLAN1 to be the management VLAN, by default all port are belong to this VLAN
configure on CORE1
interface Vlan1
ip address 172.16.1.1 255.255.255.0
end
use the same subnet for int VLAN1 on CORE2, DIST1 and ACC1, just change the last octet to 2, 3 and 4 accordingly
now all the int VLAN are up, if not then you might want to check on the trunk conf, make sure it's working
use this command, and make sure all of your trunk ports are listed, check on all switch
DIST1#sh interface trunk
Port Mode Encapsulation Status Native vlan
Fa4/3 on 802.1q trunking 1
Fa4/5 on 802.1q trunking 1
Fa4/7 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa4/3 1-4094
Fa4/5 1-4094
Fa4/7 1-4094
Port Vlans allowed and active in management domain
..
configure enable and line vty password before you can telnet all the switch using VLAN1 ip address
DIST1(config)#enable secret cisco
DIST1(config)#line vty 0 15
DIST1(config-line)#password cisco
DIST1(config-line)#privilege level 15
the line will make sure you telnet session automatically goes into the enable mode
now you should be able to telnet to all the others switch
next we'll conf VTP for easy VLAN management, on CORE1
CORE1(config)#vtp mode server
CORE1(config)#vtp domain AMD
CORE1(config)#vtp version 2
conf the CORE2, DIST1 and ACC1 to be mode client
create 4 VLAN on CORE2
CORE1(config)#vlan 10
CORE1(config)#vlan 20
CORE1(config)#vlan 30
CORE1(config)#vlan 40
show vlan on all the switch, make sure all have the same VLAN, if not then troubleshoot your VTP
now we move to spanning-tree, how to configure it? no need, by default it is turned on already(PVST), but we can control the behavior of spanning tree by manipulating a few attributes
lowest priority will become a root, if all are same value, then lowest mac address take place
in this case CORE1 has the lowest priority
show spanning-tree vlan [VLAN number]
*use show spanning-tree to to get the result for every single VLAN
by default, a single switch will become a root bridge for every single VLAN inside your network
CORE1>sh span vlan 10
VLAN0010
Spanning tree enabled protocol ieee
Root ID Priority 8192 this value should be same as Bridge ID (below), because the switch itself is Root
Address 0019.0787.300a
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 8192 priority value and ID for this switch
Address 0019.0787.300a
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi1/3 Desg FWD 19 128.3 P2p all ports in Root should be in FWD mode
Po64 Desg FWD 3 128.1665 P2p
CORE2#sh span vla 10
VLAN0010
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address 0019.0787.300a
Cost 3
Port 1665 (Port-channel64) local port going to Root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 this switch can't become a Root because CORE1 has a lower priority
Address 0019.a908.ac0a
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi7/5 Desg FWD 19 128.773 P2p port that forward traffic to the LAN segment
Po64 Root FWD 3 128.1665 P2p closest port to the root in term of cost
VLAN0010
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address 0019.0787.300a
Cost 3
Port 1665 (Port-channel64) local port going to Root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 this switch can't become a Root because CORE1 has a lower priority
Address 0019.a908.ac0a
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi7/5 Desg FWD 19 128.773 P2p port that forward traffic to the LAN segment
Po64 Root FWD 3 128.1665 P2p closest port to the root in term of cost
now we'll configure per VLAN spanning-tree, mean that we manually configure each VLAN it's own Root
there's two command to achieve this
spanning-tree vlan [VLAN X] root primary/secondary
OR
spanning-tree vlan [VLAN X] priority [Bridge ID]
we have created VLAN 10, 20, 30 and 40
divide into 2, 10 and 30 root on CORE1
20 and 40 root on CORE2
CORE1(config)#spanning-tree vlan 10 root primary
CORE1(config)#spanning-tree vlan 30 root primary
CORE2(config)#spanning-tree vlan 20 root primary
CORE2(config)#spanning-tree vlan 40 root primary
CORE1(config)#spanning-tree vlan 30 root primary
CORE2(config)#spanning-tree vlan 20 root primary
CORE2(config)#spanning-tree vlan 40 root primary
let's confirm this
VLAN0020
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address 0019.a908.ac14
This bridge is the root now this switch is the root for VLAN 20
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 8192
Address 0019.a908.ac14
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi7/5 Desg FWD 19 128.773 P2p
Po64 Desg FWD 3 128.1665 P2p
check on all the other 3 VLANs for their root
now you can configure secondary root for each VLAN using the same approach
for the second command,
remove all the configuration that we just put in, we should have the Bridge ID (by know you should know how to get the Bridge ID)
but now the problem is, all my switch have the same Bridge priority : 32788 and since CORE1 has the lowest mac, it's now the Root for all VLANs
so, I've set VLAN 10 and 30 to have a higher priority value than it's Root for now
CORE1#spanning-tree vlan 10,30 priority 36864
check on CORE2, that fella should be the Root for VLAN 20 and 30 right now
we can also confirm this on DIST1
DIST1#show spanning-tree vlan 10
VLAN0010
Spanning tree enabled protocol ieee
Root ID Priority 32768
Address 0019.a908.ac0a
Cost 19
Port 197 (FastEthernet4/5)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Address 0018.19b2.58c0
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa4/3 Altn BLK 19 128.195 P2p
Fa4/5 Root FWD 19 128.197 P2p root port for VLAN 10 is different than 20 (below), Fa4/3 connect to CORE1, Fa4/5 to CORE2
DIST1#show spanning-tree vlan 20
VLAN0020
Spanning tree enabled protocol ieee
Root ID Priority 32768
Address 0019.0787.3014
Cost 19
Port 195 (FastEthernet4/3)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32788 (priority 32768 sys-id-ext 20)
Address 0018.19b2.58c0
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa4/3 Root FWD 19 128.195 P2p connect to CORE1, it's the Root for VLAN20
Fa4/5 Altn BLK 19 128.197 P2p
another useful command
DIST1#show spanning-tree interface fastEthernet 4/5
Vlan Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
VLAN0001 Altn BLK 19 128.197 P2p
VLAN0010 Root FWD 19 128.197 P2p
VLAN0020 Altn BLK 19 128.197 P2p
VLAN0030 Root FWD 19 128.197 P2p
VLAN0040 Altn BLK 19 128.197 P2p
VLAN0050 Altn BLK 19 128.197 P2p
