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Create a trunk link between a Cisco C3550 and a C2960G Catalyst Switch

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Last Modified: 2013-07-02
Hi,

I'm trying to configure a trunk link between a Cisco C3550 (FastEthernet) and a C2960G (Gigabit) Catalyst switch, but I'm having issues. We have 5 subnets in our network infrastructure:

Subnet1: 172.16.0.0        255.255.255.192 - Production Mgmt Servers/devices
Subnet2: 192.168.0.0      255.255.255.0     - Production virtual servers
Subnet3: 172.16.0.64      255.255.255.192 - DR Mgmt Servers/devices
Subnet4: 192.168.100.0  255.255.255.0     - DR virtual servers
Subnet5: 192.168.1.0      255.255.255.0     - PCs/Laptops

The switch IPs are:
Prod-SW-01: 172.16.0.1
DR-SW-01: 172.16.0.65

I have configured 4 VLANs on each switch:

int vlan 100
int vlan 101
int vlan 200
int vlan 201

On the C2960G (Prod-SW-01), I have configured the downlink port as follows:

interface GigabitEthernet1/0/24
 description Trunk to DR-SW-01
 switchport trunk allowed vlan 100,101,200,201
 switchport mode trunk
 speed 100
 duplex full

On the C3550 (DR-SW-01), I have configured the uplink port as follows:

interface FastEthernet1/0/24
 description Trunk to Prod-SW-01
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 100,101,200,201
 switchport mode trunk
 speed 100
 duplex full

From the C3550 switch (DR-SW-01), I can ping devices on VLAN 100 and 101.
From the C2960G on VLAN 100, I can ping telnet to the switch, but cannot ping any directly connected device on VLAN200 (172.16.0.64/26).

The only thing I can see that's different is that the C3550, being an older switch prompts me to configure a VLAN encapsulation type when I attempt to make a port a trunk. The C2960G does not require this. I'm not sure if this is the problem!

Any ideas how I should go about this, change this or troubleshoot this?

Thanks,
Fin
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