Packet trace 2960 switch dropping packets

[imood]

Why does a 2960 switch drop packets from a layer 3 switch, with the message "switch does not have the Vlan indicated on the IEEE 802.1q frame tag. It drops the frame" in packet tracer, all vlans and inter vlan routing was configured? 

[David Ruess]

Only thing I can think of is the interface in the screenshot (FastEthernet0) is not the interface connected to the switch. I assume it is. You can try to put your PT file in here to see if someone can take a deeper look at it. Are other devices getting IPs from their respective pools?

[David Ruess · Accepted solution]

OK I was able to take a look. After seeing the full configs and setup I don't think that will work. Apologies I gave you some wrong information based on some assumptions. I have attached the PT file configured a bit differently.

The reason it wasn't processing the packet is because the switch is using a trunk port (to allow all VLANs to get an IP from it) but the server doesn't know how to process VLAN tags so it drops it. It needs its own subnet. Also you configured the .193 address as the helper which is the DG of the DHCP server. You need the IP of the DHCP server itself.

Changes I made:

Configured the DHCP server port on SW3 as an access port assigned to VLAN 40.

Configured the helper address of 192.168.1.195

PC0 was able to get an IP address after that. I ahve attached the PT file.

I aslo fixed a couple other things. The connection between R0 and the MLS was not in the same subnet. You were using a /30 but the interfaces IPs were in different /30 networks. I made them the same. Also your OSPF config on the MLS was configured wrong (if you were trying to advertise those VLAN subnets). You were activating OSPF on interfaces that didnt exist.

For example you had:

network 192.168.2.0 0.0.0.63 area 0

when the interface was the 192.168.1. subnet. I added the .1 interfaces but left the .2 interfaces if you want to check it out

Hope that helps

-David

[imood]

Thanks it worked, I replicated it on the other side, you forgot to mention you changed the DHCP server to into G0/2

[David Ruess]

Apologies. It was late and was moving a couple things around to try and test them. At one point I think I created a DHCP server attached to the router and changed the helper addresses and advertised that into OSPF. Glad its working now.