it's switches like these that make me pull out my hair!

This is a brand-new, 15 minute old 2950 switch and I go to connect the 3750G to a 2950, setup the SVI and assign the ip address to vlan 100 and connect it up to the 3750G and I get a native vlan mismatch. For the lab I've been using the vlan 1 as the native vlan and didn't change it across the board, but for some odd reason the 3750G was set to 100 as the native.

So I literally had to force the native with the switchport trunk native vlan 1 command for it stick, but I didn't try this at 1st cause I was like wtf I didn't set the native vlan on purpose because it was using the default....

I'm honestly truly perplexed as how how the frig this happened and why I need to specifically set the native vlan.I even went as far on the 2950 to do 'erase startup-config' and do 'delete flash:vlan.dat'.

I really have no idea wtf cause this, anyone?

anyways, the core/distro/access layer lab is all done, been doing it since 3:45 am this morning. Also had to touch my VMware lab cause I'm **** about wiring and network-design when it comes to my labs... Going to a barbecue, but now it's finished, but serious this issue for the past two hours was making me pull out my hair.

3750G-Bottom-Left#show cdp nei
3750G-Bottom-Left#show cdp neighbors de
3750G-Bottom-Left#show cdp neighbors detail

Device ID: Switch
Entry address(es):
IP address: 192.168.102.5
Platform: cisco WS-C2950C-24, Capabilities: Switch IGMP
Interface: GigabitEthernet1/0/2, Port ID (outgoing port): FastEthernet0/23
Holdtime : 125 sec

Version :
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA2, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Sun 07-Nov-04 23:14 by antonino

advertisement version: 2
Protocol Hello: OUI=0x00000C, Protocol ID=0x0112; payload len=27, value=00000000FFFFFFFF010221FF000000000000000652C10C40FF0000
VTP Management Domain: ''
Native VLAN: 100 (mismatch)
Duplex: full
Management address(es):
IP address: 192.168.102.5
--More--

3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#show running-config
Building configuration...

Current configuration : 2718 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname 3750G-Bottom-Left
!
boot-start-marker
boot-end-marker
!
!
username trevor privilege 15 password 7 094F471A1A0A
!
!
no aaa new-model
switch 1 provision ws-c3750g-24ts
system mtu routing 1500
authentication mac-move permit
ip subnet-zero
ip routing
!
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
!
!
interface Loopback0
ip address 4.4.4.4 255.255.255.255
!
interface GigabitEthernet1/0/1
!
interface GigabitEthernet1/0/2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,35-37,100,200,300,400
switchport mode trunk
!
interface GigabitEthernet1/0/3
!
interface GigabitEthernet1/0/4
!
interface GigabitEthernet1/0/5
!
interface GigabitEthernet1/0/6
!
interface GigabitEthernet1/0/7
!
interface GigabitEthernet1/0/8
!
interface GigabitEthernet1/0/9
!
interface GigabitEthernet1/0/10
!
interface GigabitEthernet1/0/11
!
interface GigabitEthernet1/0/12
!
interface GigabitEthernet1/0/13
!
interface GigabitEthernet1/0/14
!
interface GigabitEthernet1/0/15
!
interface GigabitEthernet1/0/16
!
interface GigabitEthernet1/0/17
!
interface GigabitEthernet1/0/18
!
interface GigabitEthernet1/0/19
!
interface GigabitEthernet1/0/20
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,35-37,100,200,300,400
switchport mode trunk
!
interface GigabitEthernet1/0/21
!
interface GigabitEthernet1/0/22
!
interface GigabitEthernet1/0/23
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,35-37,100,200,300,400
switchport mode trunk
!
interface GigabitEthernet1/0/24
switchport mode access
description 'uplink-to-management'
!
interface GigabitEthernet1/0/25
!
interface GigabitEthernet1/0/26
!
interface GigabitEthernet1/0/27
!
interface GigabitEthernet1/0/28
!
interface Vlan1
ip address 192.168.115.32 255.255.255.192
!
interface Vlan36
ip address 172.16.10.13 255.255.255.252
!
interface Vlan37
ip address 172.16.10.21 255.255.255.252
!
interface Vlan100
ip address 192.168.102.1 255.255.255.0
!
router ospf 1
log-adjacency-changes
network 172.16.10.0 0.0.0.31 area 0
network 192.168.102.0 0.0.0.255 area 0
network 192.168.106.0 0.0.0.255 area 0
!
ip classless
ip route 192.168.102.0 255.255.255.0 192.168.102.5
--More--
ip http server
ip http secure-server
!
!
ip sla enable reaction-alerts
!
!
!
line con 0
exec-timeout 0 0
logging synchronous
login local
line vty 0 4
exec-timeout 0 0
logging synchronous
login local
line vty 5 15
exec-timeout 0 0
logging synchronous
login local
!
end

3750G-Bottom-Left#
3750G-Bottom-Left#

*Mar 1 02:46:55.209: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/2 (100), with Switch FastEthernet0/23 (1).

3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#
3750G-Bottom-Left#show cdp neighbors detail

Device ID: 3750G-Top-Right

3750G-Bottom-Left#ping 192.168.102.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/4/9 ms
3750G-Bottom-Left#ping 192.168.102.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
3750G-Bottom-Left#

2950:

-Left GigabitEthernet ip address 192.168.115.47 255.255.255.192
no ip route-cache
shutdown
!
interface Vlan100
ip address 192.168.102.5 255.255.255.0
--More--
no ip route-cache
!
ip default-gateway 192.168.102.1
ip http server

Switch#
Switch#
Switch#
*Mar 1 02:46:55.209: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/2 (100), with Switch FastEthernet0/23 (1).
*Mar 1 02:46:55.209: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/2 (100), with Switch FastEthernet0/23 (1).
*Mar 1 02:46:55.209: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/2 (100), with Switch FastEthernet0/23 (1).
Switch#
Switch#
Switch#
Switch#show ru
Switch#show running-config
Building configuration...

Current configuration : 2512 bytes
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Switch
!
!
ip subnet-zero
!
vtp mode transparent
!
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
!
!
vlan 100
name vlan-100
!
interface FastEthernet0/1
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/2
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/3
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/4
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/5
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/6
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/7
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/8
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/9
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/10
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/11
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/12
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/13
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/14
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/15
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/16
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/17
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/18
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/19
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/20
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/21
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/22
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/23
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/24
--More--
*Mar 1 02:46:55.209: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/2 (100), with Switch FastEthernet0/23 (1). .

Switch#
Switch#wr
Building configuration...

00:29:58: %SYS-5-CONFIG_I: Configured from console by console
00:29:58: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to down[OK]
Switch#
Switch#
Switch#
Switch#
Switch#
00:30:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to upconfig t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#
Switch(config)#inter fa0/23
Switch(config-if)#switchport trunk native vl
Switch(config-if)#switchport trunk native vlan 1
Switch(config-if)#exit
Switch(config)#exit
Switch#w
00:30:55: %SYS-5-CONFIG_I: Configured from console by consoler
Building configuration...
[OK]
Switch#
Switch#
Switch#
Switch#
Switch#show cdp
Switch#show cdp ne
Switch#show cdp neighbors de
Switch#show cdp neighbors detail

Device ID: 3750G-Bottom-Left
Entry address(es):
IP address: 192.168.115.32
Platform: cisco WS-C3750G-24TS, Capabilities: Router Switch IGMP
Interface: FastEthernet0/23, Port ID (outgoing port): GigabitEthernet1/0/2
Holdtime : 145 sec

Version :
Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.2(53)SE1, RELEASE SOFTWARE (fc2)
Technical Support: Support and Documentation - Cisco Systems
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Fri 12-Mar-10 15:50 by prod_rel_team

advertisement version: 2
Protocol Hello: OUI=0x00000C, Protocol ID=0x0112; payload len=27, value=00000000FFFFFFFF010220FF0000000000000013C4448080FF0000
VTP Management Domain: ''
Native VLAN: 1
Duplex: full
Management address(es):
IP address: 192.168.115.32

Switch#
Building configuration...

Current configuration : 2524 bytes
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Switch
!
!
ip subnet-zero
!
vtp mode transparent
!
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
!
!
vlan 100
name vlan-100
!
interface FastEthernet0/1
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/2
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/3
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/4
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/5
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/6
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/7
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/8
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/9
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/10
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/11
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/12
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/13
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/14
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/15
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/16
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/17
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/18
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/19
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/20
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/21
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/22
switchport access vlan 100
switchport mode access
!
interface FastEthernet0/23
switchport trunk allowed vlan 1,100,300
switchport mode trunk
!
interface FastEthernet0/24
!
interface FastEthernet0/25
!
interface FastEthernet0/26
!

Switch#
Switch#ping 192.168.102.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms
Switch#ping 192.168.102.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
Switch#

Switch con0 is now available

Press RETURN to get started.

Switch>
Switch>enable
Switch#
Switch#
Switch#ping 192.168.102.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
Switch#ping 192.168.102.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
Switch#show cdp neigh
Switch#show cdp neighbors de
Switch#show cdp neighbors detail

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Comments

Dieg0M

The 2950 port connecting to the 3750G was probably set to an access port, so the CDP frames were being sent as untagged from VLAN 100 and this is why you saw it being the native VLAN. You could of set the 3750 side as trunk with VLAN 100 being the native VLAN and the 2950 as an access port in VLAN 100 and that would of worked. I wouldn't recommend this as you will only be able to transport 1 VLAN.

Deathmage

Dieg0M wrote: »

The 2950 port connecting to the 3750G was probably set to an access port, so the CDP frames were being sent as untagged from VLAN 100 and this is why you saw it being the native VLAN. You could of set the 3750 side as trunk with VLAN 100 being the native VLAN and the 2950 as an access port in VLAN 100 and that would of worked. I wouldn't recommend this as you will only be able to transport 1 VLAN.

Indeed that was my reasoning. Only 1 vlan works correctly in a trunk the 2950 I've seen. Maybe I need some 2960's. I think these 2950's have out lived there age.

I suppose this labbing you see things all the time you don't expect to see. I think the error before was just my sign to take a break, was going at it for 10 hours straight. Went to a family reunion instead and had a blast minus nearly hitting a freaking bear in the middle of the road, shout-out to Michelin Pilot Sport A/S 3's and Brembo brakes for the instant 65 mph to 15 pm zig-zag maneuver within 150ft.

I'm determined to put in the hours toward labbing for the next attempt. I want to eat,sleep, crap cisco till then...

alxx

I find short and sweet with goals to be achieved for each session(with time limits) rather than a marathon session works better for me.

Plan the session, broken down into tasks/parts, with a list of commands for each part, along with tests for each part so you can confirm it worked or not.