Can you draw up a network topology showing the layout.
2803SW06 said:interface FastEthernet1/7
switchport
switchport access vlan 64
switchport private-vlan trunk encapsulation dot1q
switchport private-vlan trunk native vlan tag
no switchport nonegotiate
no switchport protected
no switchport block multicast
no switchport block unicast
switchport port-security maximum 1
no switchport port-security
switchport port-security aging time 0
switchport port-security violation shutdown
switchport port-security aging type absolute
switchport port-security limit rate invalid-source-mac 10
no switchport port-security mac-address sticky
no switchport port-security aging static
ip device tracking maximum 0
no ip arp inspection trust
ip arp inspection limit rate 15 burst interval 1
ip arp inspection limit rate 15
load-interval 300
carrier-delay 2
no shutdown
mls qos cos 0
mls qos dscp-mutation Default DSCP Mutation Map
snmp trap mac-notification change added
snmp trap mac-notification change removed
snmp trap link-status
alarm profile ab-alarm
cdp tlv location
cdp tlv server-location
cdp tlv app
arp arpa
arp timeout 14400
spanning-tree port-priority 128
spanning-tree cost 0
service-policy input CIP-PTP-Traffic
hold-queue 75 in
hold-queue 40 out
ip igmp snooping tcn flood
no bgp-policy accounting input
no bgp-policy accounting output
no bgp-policy accounting input source
no bgp-policy accounting output source
no bgp-policy source ip-prec-map
no bgp-policy source ip-qos-map
no bgp-policy destination ip-prec-map
no bgp-policy destination ip-qos-map
!
2803VFDSW01 said:interface FastEthernet1/19
switchport
switchport access vlan 1
switchport private-vlan trunk encapsulation dot1q
switchport private-vlan trunk native vlan tag
switchport mode trunk
no switchport nonegotiate
no switchport protected
no switchport block multicast
no switchport block unicast
no ip arp inspection trust
ip arp inspection limit rate 15 burst interval 1
ip arp inspection limit rate 15
snmp trap mac-notification change added
snmp trap mac-notification change removed
snmp trap link-status
macro description switch-automation
alarm profile ab-alarm
cdp tlv location
cdp tlv server-location
cdp tlv app
arp arpa
arp timeout 14400
spanning-tree link-type point-to-point
spanning-tree port-priority 128
spanning-tree cost 0
hold-queue 75 in
hold-queue 0 out
ip igmp snooping tcn flood
ip dhcp snooping limit rate 4294967295
no ip dhcp snooping trust
no ip dhcp snooping information option allow-untrusted
no bgp-policy accounting input
no bgp-policy accounting output
no bgp-policy accounting input source
no bgp-policy accounting output source
no bgp-policy source ip-qos-map
no bgp-policy destination ip-prec-map
no bgp-policy destination ip-qos-map
!
2803VFDSW02 said:interface FastEthernet1/20
switchport
switchport access vlan 1
switchport private-vlan trunk encapsulation dot1q
switchport private-vlan trunk native vlan tag
switchport mode trunk
no switchport nonegotiate
no switchport protected
no switchport block multicast
no switchport block unicast
ip device tracking maximum 0
no ip arp inspection trust
ip arp inspection limit rate 15 burst interval 1
ip arp inspection limit rate 15
load-interval 300
carrier-delay 2
no shutdown
snmp trap mac-notification change added
snmp trap mac-notification change removed
snmp trap link-status
macro description switch-automation
alarm profile ab-alarm
cdp tlv location
cdp tlv server-location
cdp tlv app
arp arpa
arp timeout 14400
spanning-tree link-type point-to-point
spanning-tree port-priority 128
spanning-tree cost 0
hold-queue 75 in
hold-queue 40 out
ip igmp snooping tcn flood
no bgp-policy accounting input
no bgp-policy accounting output
no bgp-policy accounting input source
no bgp-policy accounting output source
no bgp-policy source ip-prec-map
no bgp-policy source ip-qos-map
no bgp-policy destination ip-prec-map
no bgp-policy destination ip-qos-map
!
I think the way to interpret the cisco config is as follows:
>>switchport mode trunk
This puts the port in trunk mode. Since there is no other command to set the config otherwise, the native vlan on this trunk port would be 1.
>>switchport access vlan 1
This sets the access vlan, IF the port is an access port. However, with the switchport mode trunk command, it is not. Therefore, this has no effect in this config (on this port).
So two of the switches are trunk ports, and the third is an access port. CDP will indicate the native vlan for each port, so you would have a mismatch. The access port will indicate the access vlan and the trunks I expect to advertise a native vlan of 1.
Also the access port does not expect to see spanning tree BPDUs, so is throwing the error you see about inconsistent ports.
As brendan says - don't you want all your inter-switch links to be trunks?