07-16-2008 04:48 AM - edited 03-03-2019 10:45 PM
Good morning,
I will first preface this by saying that my Cisco skills are a bit rusty. While I have a CCNA, that was earned about three years ago and I've only had to use it sparingly since then; a testament to the quality of the product I suppose.
Anyway, here's my issue. At my new job we recently installed a Cisco 3560 to replace some Netgears that were on the network (don't ask why those were there, I really don't know). On the Netgears there were two VLANs setup. One was for the subnet with all the company's core servers (172.20.x.x/16) while the other went to a subnet dedicated to an EMC Celerra SAN system (172.21.10.x/24).
The previous Netgears connected into two different Extreme 24 port switches via 1 gigabit copper ports. The Cisco 3560 we put in their place connect back to one of the Extreme switches. It connects via two copper gigabit connections, one which is on the VLAN for the servers, the other for the VLAN of the EMC device.
I'll include some of the config here.
int g0/1
swithcport access vlan 51
switchport mode dot1q-tunnel
This gigabit port connects back to the Extreme switch which then connects to other switches
g0/24
switchport access vlan 20
switchport access dot1q-tunnel
This one also connects back to the same Extreme switch as g0/1
Interface VLAN1
No ip address
Interface VLAN20
IP address 172.21.10.4 255.255.0.0
Interface VLAN51
ip address 172.20.10.1 255.255.255.0
While the switching is working between all of the devices (hooray!) there are some other issues that have cropped up that I'm uncertain how to handle.
1. I can not seem to telnet into the device. I feel pretty confident that the IP address I gave the two VLANs were not in use but pinging and telnetting to it does not work.
2. On the EMC Celerra device there are actually 4 NICs going into the switch. on the ports those NICS are connected to, I received notifications that a MAC address on g0/3 and g0/4 is "flapping" while the same is being shown on g0/13 and g0/14. Performance doesn't seem to be hurting, but this notification keeps popping up on the switch when I'm plugged in via the console port.
Any help or suggestions would be greatly appreciated. Thanks!
-JLF
07-16-2008 05:04 AM
conf t
vlan 20
vlan 51
int g0/1
no swithcport access vlan 51
no switchport mode dot1q-tunnel
sw tr enc dot1q
sw mo tr
int g0/24
no swithcport access vlan 51
no switchport mode dot1q-tunnel
sw tr enc dot1q
sw mo tr
Interface VLAN20
no sh
Interface VLAN51
no sh
[Pls RATE if HELPS]
07-16-2008 05:08 AM
So, if I understand this correctly:
1. Enter config mode
2. Create the VLANs again?
3. On the g0/1 interface turn off the settings I currently have and setup trunking instead.
4. Do the same on the g0/24
5. Do a no shutdown on both VLANs.
07-16-2008 05:16 AM
You understand correctly.
2. if you already have vlan20 and vlan51 in the vlan database, you may skip the step.
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: