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Cisco 2948 Switch

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crmayer

Programmer
Joined
Nov 22, 2002
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I have a problem with a Cisco 2948 Switch. We just purchased it today due to expansion and moving to a new building. I have 4 HP Pro Curve 2524 switches, and this Cisco one now. I have daisy chained them together and any PC that is connected to the Cisco switch can not access anything on the network.
The NIC light is lit and the port light is lit, but it will not obtain an IP.
Now for the dumb question, I know very little about Cisco, but should this thing be ready out of the box, or is there some configuring that should be done before it will work?
 
It depends on how your switched network is configured at the moment.

If you have deployed a VTP domain and segmented the network using layer 2 VLANs, then yes it is entirely plausible the Cisco switch will need configuring accordingly.

If the rest of your non-Cisco switches have also been deployed 'out of the box' then potentially I'd have thought the Cisco would be able to integrate with them (albeit I don't know what the default settings are for HP switches).

Reviewing the configuration of the existing switches will likely be the best way forward. Try and determine if multiple VLANs are being deloyed, whether trunks have been setup on the physical port between them and what the VTP domain settings are.
 
If you can manually assign an address and get to the network ok then you just a have a spanning tree issue . On "all" user ports on the Cisco switch issue the "set port host" command . This turns on portfast and turns off trunking and channeling for the user ports . By default portfast is not turned on for cisco switches thus when a nic powers up it has to wait for spanning tree to go thru the full bringup which is around 50 seconds thus dhcp times out waiting and will not pull an address .
 
You may also want to ensure that the port(s) uplinked to the other switches are not trying to dynamically trunk. Out of the box, cisco switches come set with:

switchport mode dynamic desirable

This will cause the switch to negociate a trunk with the other side if possible. In a perfect world, the switch would see it was impossible and set itself up for:

swithport mode access

But the world is not perfect.

Like KiscoKid, I don't know how HP works out the box. But if you are indeed running vlans, be sure to set your trunk to dot1q encapsulation, as ISL is cisco proprietary!!

switchport trunk encapsulation dot1q
switchport mode trunk <if the trunk is not negociating properly>

Otherwise if you are not using vlans, then switchport mode access will force your switch to uplink similar to a hub.
 
Thanks for all the help, but my knowledge with cisco is VERY limited. We had to have somebody from the place we purchased this thing from come out and fix it. Since we had about 20 clients on this switch, I had to have it running my Monday morning.

Again, thanks for all the help.
It ended up being something with the VLAN settings.
 
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