05-12-2010 03:39 PM - edited 03-06-2019 11:03 AM
First time poster here and I am stumped! I have two Catalyst 4006 switches that are on different floors of the same building. I want to replace one of the switches with a smaller switch, a WS-C2960g-8tcl. They are connected via fiber. I was able to connect the new 2960 switch to the Catalyst 4006. VTP is on for the 4006. On the 2960 I verified VTP is being received and the VLANs are listed properly. On the 2960 I assigned ports 1-7 to VLAN 24 port 8 is the SFP. On ports 1-7 I am not receiving IP addresses. I turned trunking on and off, no change either way. Does anyone have any ideas? I can post configurations if needed.
Thanks,
Michael
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05-12-2010 03:50 PM
First time poster here and I am stumped! I have two Catalyst 4006 switches that are on different floors of the same building. I want to replace one of the switches with a smaller switch, a WS-C2960g-8tcl. They are connected via fiber. I was able to connect the new 2960 switch to the Catalyst 4006. VTP is on for the 4006. On the 2960 I verified VTP is being received and the VLANs are listed properly. On the 2960 I assigned ports 1-7 to VLAN 24 port 8 is the SFP. On ports 1-7 I am not receiving IP addresses. I turned trunking on and off, no change either way. Does anyone have any ideas? I can post configurations if needed.
Thanks,
Michael
Michael
Is the DHCP server in vlan 24 ? If so can you make sure vlan 24 is allowed on the trunk link. If the DHCP server is on a different vlan then where is the vlan 24 L3 interface and does it have an "ip helper-address" command configured.
Can you answer the above and post out of "sh int trunk" from the 2960G.
Jon
05-12-2010 03:50 PM
First time poster here and I am stumped! I have two Catalyst 4006 switches that are on different floors of the same building. I want to replace one of the switches with a smaller switch, a WS-C2960g-8tcl. They are connected via fiber. I was able to connect the new 2960 switch to the Catalyst 4006. VTP is on for the 4006. On the 2960 I verified VTP is being received and the VLANs are listed properly. On the 2960 I assigned ports 1-7 to VLAN 24 port 8 is the SFP. On ports 1-7 I am not receiving IP addresses. I turned trunking on and off, no change either way. Does anyone have any ideas? I can post configurations if needed.
Thanks,
Michael
Michael
Is the DHCP server in vlan 24 ? If so can you make sure vlan 24 is allowed on the trunk link. If the DHCP server is on a different vlan then where is the vlan 24 L3 interface and does it have an "ip helper-address" command configured.
Can you answer the above and post out of "sh int trunk" from the 2960G.
Jon
05-12-2010 04:24 PM
DHCP is not on the same subnet. The old 4006 that I am replacing was on Vlan 24 and it was working then. I also tried manually assigning an IP that is in the VLAN 24 range but to no avail.
Here are the results from the 2960:
sw7.1#sh int trunk
Port Mode Encapsulation Status Native vlan
Gi0/8 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi0/8 1-4094
Port Vlans allowed and active in management domain
Gi0/8 1-10,24,32-33,50-54,99-101
Port Vlans in spanning tree forwarding state and not pruned
Gi0/8 1-10,24,32-33,50-54,99-101
05-12-2010 04:33 PM
Can you post config of 2960 + "sh ip int brief" off 2960G.
Also post config from 4006. I'm assuming the 4006 is routing for the vlans ??
Jon
05-12-2010 06:06 PM
On the 2960 ports make sure you have portfast turned on for ports 1-7 . If you can't statically assign one and get around then the trunk is most likely not working correctly . If you can post the uplink configs for the 2960 and the config on the 4006 .
05-13-2010 02:33 PM
Eureka, I figured it out! The router module on the 4006 that is being replaced was handling the routing for VLAN 24. When I looked at the gig interface that I was plugged into I noticed that VLAN 24 was not defined as a sub interface. I assigned the ports on the 2960 to VLAN 50, which was defined as a sub interface, DHCP and IP traffic began to function. Now I know that my trunk is working properly. When I go to decommission the 4006 I will add a Vlan 24 sub interface to the remaining 4006.
Thanks, Jon and Glen for your help I truly appreciate it!
Michael
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