Create a trunk link between a Cisco C3550 and a C2960G Catalyst Switch
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
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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I'm out on site this morning, but when I get back to the office, I'll get sh runs of both switches and sh vlans.
There is a default gateway set that is pingable (192.168.0.220 - this is a core switch that is uplinked from the C2960g) .
I can ping a laptop that is directly connected to the C3550 on port 1. The laptops IP is 172.16.0.82/26.
I don't have 'IP routing' configured on the C3550.
There is a default gateway set that is pingable (192.168.0.220 - this is a core switch that is uplinked from the C2960g) .
I can ping a laptop that is directly connected to the C3550 on port 1. The laptops IP is 172.16.0.82/26.
I don't have 'IP routing' configured on the C3550.
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Please send in the show run of the core switch as well and maybe a little drwaing on how you have connected allt the switches.
The default gateway IP address of your switches needs to be in the same subnet as their IP addresses.
The default gateway IP address of your switches needs to be in the same subnet as their IP addresses.
ASKER
Apologies for the late allocation of points here - There were a number of issues with the network that I came across, mainly due to your suggestions and questions above.
The network was originally configured as follows:
Core Switch (C3550) -> Production Switch (C2960S) -> DR Switch (C3550)
When it should have been configured with the Core Switch routing directly to the Production and DR switches:
Core Switch (C3550) -> Production Switch (C2960S)
Core Switch (C3550) -> DR Switch (C3550)
This solved the routing issue as both Prod and DR switches then had the same gateway IPs.
I was a bit rusty with my networking and had lost the concept of layer 2 and layer 3 VLANs, but once you pointed that out I was able to troubleshoot accordingly.
The trunk ports VLANs were also configured incorrectly so your suggestions also help me resolve that issue.
Thank you.
The network was originally configured as follows:
Core Switch (C3550) -> Production Switch (C2960S) -> DR Switch (C3550)
When it should have been configured with the Core Switch routing directly to the Production and DR switches:
Core Switch (C3550) -> Production Switch (C2960S)
Core Switch (C3550) -> DR Switch (C3550)
This solved the routing issue as both Prod and DR switches then had the same gateway IPs.
I was a bit rusty with my networking and had lost the concept of layer 2 and layer 3 VLANs, but once you pointed that out I was able to troubleshoot accordingly.
The trunk ports VLANs were also configured incorrectly so your suggestions also help me resolve that issue.
Thank you.
What IP address is the default gateway in each VLAN?
On what device is that IP address located?