09-25-2013 05:48 AM - edited 03-07-2019 03:40 PM
Hello everyone,
I have a problem getting a trunk port working between a 3750 stack and a 4507 chassis. The 4507 will form my new core but I am trying to configure it along side before testing and rollout but can't get it talking on my management VLAN. I have a VLAN setup as my management network on the 3750 but cannot get it to ping the new 4507, an excerpt from my config is below
interface Vlan21
description Native
ip address 10.50.0.129 255.255.255.128
end
I have also setup the 4507 with VLAN 21
interface Vlan21
ip address 10.50.0.131 255.255.255.128
no ip route-cache
end
VTP has been set to server on the 3750 and client on the 4507 but I still cannot ping the interfaces from each device
Port Config on the 3750
interface GigabitEthernet2/0/24
description Server Core LINK
switchport trunk encapsulation dot1q
switchport trunk native vlan 21
switchport mode trunk
end
Port Config on the 4507
interface GigabitEthernet1/48
switchport trunk native vlan 21
switchport mode trunk
end
Any help would be apprecaited
Thanks
Matt
09-25-2013 11:12 AM
Is the L2 vlan created on both sides ?? Show vlan to verify vlan 21 is operating on both sides, trunk setup looks ok . Is this a client/server setup or transparent ? If client/server check the vtp domain name. L1 connectivity show as active or connected ?
09-25-2013 12:33 PM
You can also check cdp for information, and ip route table. Does the rest of vlans pass from the link?
In vtp check domain, version, authentication.
Also issue the switchport trunk encapsulation dot1q on both interfaces. Check interfaces for config with show interface gig1/48 switchport and post results.
Sent from Cisco Technical Support Android App
09-25-2013 02:09 PM
Looks like your tagging traffic and only have dot1q on one side of the trunk. As Panos mentioned, please configure on both sides and post results.
09-26-2013 02:11 AM
Tagging is set up on both sides on the trunk:
Switch#show int gi1/48 switchport
Name: Gi1/48
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
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 associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
show CDP Neighbours shows nothing
VTP domain and configuration is at same version with the 3750 set as server the the 4507 set as client.
09-26-2013 02:27 AM
You seem to be lacking on layer 2.
can you please confirm the output of "sho vlans" and "sho int trunk" ?
09-26-2013 02:31 AM
4507:
Show vlan -
21 Native active
Show Int Trunk: -
show int trunk
Port Mode Encapsulation Status Native vlan
Gi1/48 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi1/48 1-4094
Port Vlans allowed and active in management domain
Gi1/48 1,21
Port Vlans in spanning tree forwarding state and not pruned
Gi1/48 1,21
3750
Show vlan: -
21 Native active Gi2/0/7
Show Int Trunk: -
brighton_3750_core#show int trunk
Port Mode Encapsulation Status Native vlan
Gi1/0/23 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi1/0/23 1-4094
Port Vlans allowed and active in management domain
Gi1/0/23 1-2,4-7,21,32,49,65
Port Vlans in spanning tree forwarding state and not pruned
Gi1/0/23 1-2,4-7,21,32,49,65
09-26-2013 02:38 AM
and one more :
sho ip int br
09-26-2013 02:39 AM
3750:
Vlan21 10.50.0.129 YES manual up up
4507:
Vlan21 10.50.0.131 YES NVRAM up up
09-26-2013 03:31 AM
Hi Matt
I would start again from scratch.
Reset the config on both ports (unplug the cable from one end first)
#default interface GigabitEthernet2/0/24
#default interface GigabitEthernet1/48
This will reset the config on both ports back to default, i.e nothing.
Then do the following:
interface GigabitEthernet2/0/24
description Server Core LINK
switchport mode trunk
switchport trunk encapsulation dot1q
switchport trunk alllowed vlan 21
interface GigabitEthernet1/48
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan 21
end
You should then be able to access your new core switch from the 3750. Also make sure, Vlan 21 actually exists on the new core switch as a L2 Vlan and the SVI is not shut down.
Thanks
09-26-2013 02:49 AM
Hello,
1- try to apply below simple command to allow vlans to have a traffic thorugh the trunk linmk:
yourdevice(config-if)#switchport trunk allow vlan X,Y,Z .............. apply this command on both trunk interfaces from both devices.
2- for the MLS cisco devices some times you need to apply below command to provide the traffic between different vlans;
# ip routing
- according to the show output the native vlan from both ends still vlan 1 and not vlan 21.
regards,
09-26-2013 02:54 AM
I have allowed specific VLANs on both trunk interfaces and confirmed that ip routing is enabled on both devices.
Still having the same issue
Thanks
Matt
09-26-2013 03:09 AM
Hi,
correct, you allowed the vlans but still vlan 1 is the native vlan from both devices.
can you check this again plerase?
regards,
09-26-2013 03:12 AM
Both sides have been set to native VLAN 21 to test. Still the same result
09-26-2013 03:17 AM
check the native vlan by apllying command show int trunk
and this time try to configure a dynamic routing protocol.
router eigrp 65010
net x.x.x.x
net x.x.x.x
no auto-summary
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