set trunk 1/30 desirable negotiate 1-4094 =E2=80=93 (Here is the messup !!= !)
All Access switches connected to Distribution switch, started going down and not reachable =EF=81=8C, parallely we got this STP error In CoreSw
CoreSW > (enable) set trunk 1/30 desirable negotiate 1-4094 Vlan(s) 1-4094 already allowed on the trunk Please use the 'clear trunk' command to remove vlans from allowed list. Port(s) 1/30 trunk mode set to desirable. Port(s) 1/30 trunk type set to negotiate. Core switch> (enable) 2009 Jul 30 21:37:50 DST -07:00 %ETHC-5- PORTFROMSTP :Port 1/30 left bridge port 1/30
2009 Jul 30 21:37:53 DST -07:00 %ETHC-5-PORTTOSTP:Port 1/30 joined bridge port 1 /30 2009 Jul 30 21:37:54 DST -07:00 %SPANTREE-2-RX_1QNONTRUNK: Rcved 1Q- BPDU on non- trunk port 1/30 vlan 50 from 00-19-56-bd-a1-b1 2009 Jul 30 21:37:54 DST -07:00 %SPANTREE-2-RX_1QPVIDERR: Rcved pvid_inc BPDU on 1Q port 1/30 vlan 50 from 00-19-56-bd-a1-b1 2009 Jul 30 21:37:54 DST -07:00 %SPANTREE-2-RX_BLKPORTPVID: Block 1/30 on rcving vlan 50 for inc peer vlan 1 4) So, we reverted all the changes by using the command =E2=80=9Cclear trun= k 1/30=E2=80=9D on CoreSW- 5) Then, took console access to all of these non reachable Acc Switch, there the uplink port was err-disabled with the following logs: Jul 30 21:44:13.616 PDT: %PM-4-ERR_DISABLE: loopback error detected on Gi0/1, putting Gi0/1 in err-disable state . Jul 30 21:44:14.622 PDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down . Jul 30 21:44:15.646 PDT: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to down Re enabled err-disabled ports in all the non reachable access switches with shut, no shut command 6) From the logs from the core switch highlighted above we thought, its due to the native vlan clash, hence we thought of configuring the trunk port=E2=80=99s native vlan as 50 7) So, again logged in Distribution switch and tried with the below commands: interface GigabitEthernet0/49 switchport trunk native vlan 50 switchport mode dynamic desirable switchport trunk encapsulation dot1q switchport trunk allowed vlan 50,56And in CoreSwitch the same command set trunk 1/30 desirable negotiate 1-4094 (Again same issue and these are the errors in Coreswitch this time
Core switch> (enable) 2009 Jul 30 23:40:42 DST -07:00 %SPANTREE-2- RX_1QNO NTRUNK: Rcved 1Q-BPDU on non-trunk port 1/30 vlan 50 from 00-19-56-bd- a1-b1
Core switch> (enable) 2009 Jul 30 23:45:26 DST -07:00 %SPANTREE-2- PORTUNB LK: Unblock previously inc port 1/30 on VLAN 50
Again, all the Access switches connected to Distribution switch-a become not reachable, so again we repeated the same above steps and reverted all the config to the old setup