05-29-2007 07:47 AM - edited 03-03-2019 05:12 PM
Just curious:
In a 3750 switch, I see in the 'show run' Vlan 1 is configured as 1.1.1.1 IP address.
Why the 'show vlan' below doesn't show fa0/1/24 associated with Vlan1 then? In which vlan is port fa0/1/24 associated with then??
Switch#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- ------------------------------
1 default active Fa1/0/1, Fa1/0/2, Fa1/0/3
Fa1/0/4, Fa1/0/5, Fa1/0/6
Fa1/0/7, Fa1/0/8, Fa1/0/9
Fa1/0/10, Fa1/0/11, Fa1/0/12
Fa1/0/13, Fa1/0/14, Fa1/0/15
Fa1/0/16, Fa1/0/17, Fa1/0/18
Fa1/0/19, Fa1/0/20, Fa1/0/21
Fa1/0/22, Fa1/0/23, Gi1/0/1
Gi1/0/2
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
Switch#
Switch#show ip int brief
Interface IP-Address OK? Method Status Protoc
Vlan1 1.1.1.1 YES NVRAM up up
FastEthernet1/0/1 unassigned YES unset down down
FastEthernet1/0/2 unassigned YES unset down down
FastEthernet1/0/3 unassigned YES unset down down
FastEthernet1/0/4 unassigned YES unset down down
FastEthernet1/0/5 unassigned YES unset down down
FastEthernet1/0/6 unassigned YES unset down down
FastEthernet1/0/7 unassigned YES unset down down
FastEthernet1/0/8 unassigned YES unset down down
FastEthernet1/0/9 unassigned YES unset down down
FastEthernet1/0/10 unassigned YES unset down down
FastEthernet1/0/11 unassigned YES unset down down
FastEthernet1/0/12 unassigned YES unset down down
FastEthernet1/0/13 unassigned YES unset down down
FastEthernet1/0/14 unassigned YES unset down down
FastEthernet1/0/15 unassigned YES unset down down
FastEthernet1/0/16 unassigned YES unset down down
FastEthernet1/0/17 unassigned YES unset down down
FastEthernet1/0/18 unassigned YES unset down down
FastEthernet1/0/19 unassigned YES unset down down
FastEthernet1/0/20 unassigned YES unset down down
FastEthernet1/0/21 unassigned YES unset down down
FastEthernet1/0/22 unassigned YES unset down down
FastEthernet1/0/23 unassigned YES unset down down
FastEthernet1/0/24 unassigned YES unset up up
GigabitEthernet1/0/1 unassigned YES unset down down
GigabitEthernet1/0/2 unassigned YES unset down down
Switch#
Solved! Go to Solution.
05-29-2007 09:34 AM
Marlon
This additional output is quite helpful. It answers my question about trunking - and shows that I did not really ask quite the right question. In your switch there is no configuration of trunking. But trunking negotiation is enabled as shown by:
Negotiation of Trunking: On
The Administrative Mode is dynamic auto and the Operational Mode is trunk. So it looks as though the neighbor has requested trunking using ISL.
So it all looks ok to me. And explains nicely why fa1/0/24 does not show up in the ports in vlan 1 because trunk ports do not show up as members of the VLAN.
HTH
Rick
05-29-2007 07:55 AM
Marlon
I do not believe that you have given us sufficient detail to be able to answer your question. The fact that show vlan does not indicate that fa1/0/24 is in any VLAN makes me assume that the interface is not configured as an access port (in some VLAN) but is configured as a routed port. But the output of show ip interface brief does not indicate that the port has been assigned an IP address. So I am guessing that it is a routed port without any IP address. Perhaps you can post the output of show run for the interface. This would help us to resolve your question.
HTH
Rick
05-29-2007 08:13 AM
As you can see, there is no configuration related to the port fa0/1/24 making it a no switchport (layer 3). Ah, I think if the 'no switchport' was issued on fa0/1/24, that should not show up in the 'show run', right?
Switch#show run
Building configuration...
Current configuration : 1375 bytes
!
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
(...)
interface FastEthernet1/0/9
!
interface FastEthernet1/0/10
!
interface FastEthernet1/0/11
!
interface FastEthernet1/0/12
!
interface FastEthernet1/0/13
!
interface FastEthernet1/0/14
!
interface FastEthernet1/0/15
!
interface FastEthernet1/0/16
!
interface FastEthernet1/0/17
!
interface FastEthernet1/0/18
!
interface FastEthernet1/0/19
!
interface FastEthernet1/0/20
!
interface FastEthernet1/0/21
!
interface FastEthernet1/0/22
!
interface FastEthernet1/0/23
!
interface FastEthernet1/0/24
!
interface GigabitEthernet1/0/1
!
interface GigabitEthernet1/0/2
!
interface Vlan1
ip address 1.1.1.1 255.255.255.0
!
ip classless
ip http server
!
!
(...)
05-29-2007 08:57 AM
Well, if I do 'no switchport' in reality I see that it should appear in thet 'show run'...
05-29-2007 09:15 AM
Marlon
Yes, if you do no switchport that command should show up in the running config. The interface should always show up in the running config, whether it is a switch port or a routed port.
If the output of show run was the original configuration then I am quite puzzled about fa1/0/24. From that configuration I would assume that it was a member of the VLAN. I do not understand why it is not included in the output of show vlan. I notice that it is the only interface that shows as being up. Can you tell us what is connected to that interface? Also is there any configuration of trunks in that configuration?
HTH
Rick
05-29-2007 09:23 AM
If I do 'show cdp neig detail', I see that I have a 3550 switch connected to that port fa1/0/24.
The if I do 'show int fa1/0/24 switchport', I get the output below. The only thing unusual I see is that it is doing isl (instead of dot1q). Not sure if the below can clarify this(?)
Name: Fa1/0/24
Switchport: Enabled
Administrative Mode: dynamic auto
Operational Mode: trunk
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: isl
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
05-29-2007 09:34 AM
Marlon
This additional output is quite helpful. It answers my question about trunking - and shows that I did not really ask quite the right question. In your switch there is no configuration of trunking. But trunking negotiation is enabled as shown by:
Negotiation of Trunking: On
The Administrative Mode is dynamic auto and the Operational Mode is trunk. So it looks as though the neighbor has requested trunking using ISL.
So it all looks ok to me. And explains nicely why fa1/0/24 does not show up in the ports in vlan 1 because trunk ports do not show up as members of the VLAN.
HTH
Rick
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