VLAN trunking between Cisco 2950 and linux box

donglee · 03-26-2014, 07:59 AM

I'm having trouble to configure these two. Let me know if there are any online resources, though I've tried.

Cisco WS-C2960-24TT-L is a 24 port switch.
I'd like make port 2 for trunking of vlan 2 and 5.
Here vlan 2 will have port 3, 4 and
vlan 5 will have port 5, 6, 7, 8.

I've added two vlan at eth1 of my linux box using following commands:
vconfig add eth1 2
vconfig add eth1 5

eth1.2 Link encap:Ethernet HWaddr 00:E0:4C:56:29:9D
inet addr:10.0.0.33 Bcast:10.0.0.63 Mask:255.255.255.224

eth1.5 Link encap:Ethernet HWaddr 00:E0:4C:56:29:9D
inet addr:10.0.0.129 Bcast:10.0.0.159 Mask:255.255.255.224

Now, from a host 10.0.0.35/27 connected to cisco2950 port 3, I can ping 10.0.0.34 but cannot reach 10.0.0.33 and

From linuxbox 10.0.0.33/27 I can't ping 10.0.0.34 or 10.0.0.35.
Interesting things is that I can see the packets trying from 10.0.0.35 using
tcpdump -i eth1

Little help will be highly appreciated.

Thanks.

Ser Olmy · 03-26-2014, 09:02 AM

Make sure the trunk port is manually configured to act as a trunk (switchport mode trunk), because neither of the dynamic modes will work. Also, check that neither 2 nor 5 is the "native VLAN" for the trunk port.

If it still doesn't work, post the output from show interfaces trunk and show running-config (sanitized if necessary).