Switch - Connecting a 4948 to 3750

[Peter_mlr]

Hi There -

I have got a new 48port Cisco catalyst 4948 switch, which I configured as a VTP client and connected to Cisco 3750 which is a VTP Server (this switch is on production network). I connected port g1/0/48 from 3750 to port g1/48 on 4948 through a straight cable and made both ports as trunk port (I also tried through cross cable). The problem is these two switches are not detecting. For testing I connected a PC directly to one of the port on 4948 (making that a switch port) still the LED on switch didn’t glow up.

Is there any special command needs to be run on 4948 switches to activate its physical ports?

On 3750

Interface GigabitEthernet1/0/33

Switch port trunk encapsulation dot1q

switchport mode trunk

logging event trunk-status

end

SWITCH_3750#show int g1/0/33

GigabitEthernet1/0/33 is down, line protocol is down (notconnect)

Hardware is Gigabit Ethernet, address is 001f.6dfd.c921 (bia 001f.6dfd.c921)

On 4948

!
interface GigabitEthernet1/48
switchport trunk encapsulation dot1q
switchport mode trunk
end

Switch_4948#show int g1/48
GigabitEthernet1/48 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet Port, address is 1cdf.0f85.606f (bia 1cdf.0f85.606f)

Switch_4948#show mac address-table
Multicast Entries
vlan    mac address     type    ports
-------+---------------+-------+--------------------------------------------
   1    ffff.ffff.ffff   system

Pls suggest

[glen.grant]

   No there is nothing special about the 4948 .  Do a show int status on both boxes

and make sure one of them did not err-disable the ports for some reason .  If using straight thru make sure auto mdix is activated on the 3750  and the port settings are auto/auto on both ends .

[Peter_mlr]

Hi, Thanks for your reply.

You can see above that I have copied the interface status and where in both status doesn't seems to be on err-disable. As I mentioned 3750 is already on the production network with many trunks connected to cisco 2960 and other switches through straight cable. With that said, we can make out that auto mdix is already enabled. Since both ports are ‘Gig’ I believe it should negotiate and come up (atleast when I connect a PC to one of the port on 4948 it should have worked. isn’t it? )

Thanks

Peter

[Peter_mlr]

`

[Yogesh Ramdoss]

Peter,

I assume the 4948 switch you have has 1Gig SFP/Fiber uplink ports, not 10Gig.

If possible, llet me know the exact PID and IOS version.

I assume this issue is with one of the 10/100/1000 mbps copprt port. Confirm.

Have you tried to shut/no shut the interface ? Very basic question, still would like

to know. Does any of these ports up and running ?

Earlier, we have seen similar issues reported with fiber ports. Please review

CSCsj67573.

- Yogesh

[Matthew Fieldhouse]

Don't worry, there's nothing wrong with your switch!

Old post, I know - but I'm configuring two 4948's and was a little bit confused when I couldn't connect their Gi 1/48 interfaces together

Here's the solution

The last 4 RJ45 ports Gi1/48 are shared with the 4 SFP ports on the end of the switch.

You have to choose between either the RJ45 or SFP. By default, the switch will use the SFP ports

To get Gi 1/45 - 1/48 working, configure under the interfaces: 'media-type rj45'

[robert.brady]

You sir, are a genius! 

I've just spent the last hour testing ports in our datacentre, testing cables etc before finally coming back to what I know.  Google!

Rob

[joro]

Matthew,

Thank you from me as well. I suspected something like that because of the similarity with 3Com switches but I was google-ing to find the answer for Cisco 4948