migrating from catalyst Switch 2960 to 3750

[Kouontchou]

Hi all. I'm migrating from a 2960 to a 3750 Switch. I have copy the configurations from the 2960, change the interface labelling (fa1/0 to fa1/0/1) and the switch hostname, pasted the configurations in the new switch but users can not access the network. I verify the VTP configurations and apply them in the new switch but users still not have access to the network. I dont know if i am missing something. I real need your help. Find attached the config file.

[Leo Laohoo]

What troubleshooting have you done?  

The immediate thing that pops out is:  Where's your VLAN???

VLAN 2 is not in the VLAN database.  Therefore I can conclude that the 3750 is running a very old, old IOS (one which does NOT automatically create the VLAN database).

[Kouontchou]

Thanks for your reply.The VLAN configurations are done automatically through VTP when i did the VTP configurations i received all the VLAN configurations.

[Leo Laohoo]

interface GigabitEthernet1/0/1
description To_burfab-3750g-sw-1_Port_G1/0/2
switchport mode trunk

Hold on.  There's something missing with this command.  This link is NOT suppose to work.  

Where is the command "switchport trunk encapsulation dot1q"?

[Kouontchou]

But the link is working with the same config on the old Switch surely using the default ISL encapsulation

[Richard Bradfield]

You have to define the encapsulation dot1q or ISL on the trunk ports

are the radius servers accessible from the 3750?

do users get an IP address on the correct vlan?

is the 3750 switch in the radius database as a network device.?

[Kouontchou]

I will defines the encapsulation.

yes from the switch I can ping the radius server

users didn't receive any ip addresses.

I did not verify the radius database but I think the server will keep the ip address of the 2960 that I have not changed in the 3750. Or the radius server keep instead the hostname that I have changed ?

[Richard Bradfield]

you will most probably need to look into the radius logs to see if the clients attempt authentication and or reason for failure, also where is the DHCP server for the users?

[Kouontchou]

Thanks all for your replies. What I'm wondering is why the same config is working well with the 2960 but not working with the 3750? Apart of the VLAN configurations that may not appear in the startup config of the 2960, what else should I verify? If I deactivate 802.1x authentication can this solve the problem? I will verify the DHCP configurations.

[Richard Bradfield]

Hi,

If you deactivate dot1x you will need to add a "switchport access vlan xx" to the interfaces of the 3750 switch.

[devils_advocate]

You need to look at the logs on the Radius server to see if you can see any authentication attempts. 

[Leo Laohoo]

But the link is working with the same config on the old Switch surely using the default ISL encapsulation

Default?  There is no such thing as ISL being the "default" in Trunking.  

Remember, the command was a cut-and-paste from a 2960.  In Catalyst 2K, Dot1Q is the default command because Catalyst 2K do NOT support ISL.