Cisco – XenServer 6.0.2 and Cisco 3550 vlan configuration

ciscocisco-catalystvlanxenserver

I am running a couple of xenserver 6.0.2 hosts with multiple vm's on them. All the xen hosts have 4 physical network ports connecting to the cisco. Each port is untagged in xen but is tagged to a vlan inside the cisco (with access mode vlan x). This is working as expected for quite some time now.

However now I would like to use one of the interfaces for multiple vlan's.

I created a new network in Xen with vlan tag 4.

The config in the cisco is (for all ports with the extra vlan in xen):

interface FastEthernet0/5
  switchport trunk encapsulation dot1q
  switchport trunk native vlan 3
  switchport trunk allowed vlan 3,4
  switchport mode trunk
  spanning-tree portfast trunk

I created 2 test vm's (on different hosts) and added the new network to them. However they cannot see (or ping) each other. I also cannot ping the cisco on its ip in vlan4.

Am i missing something? I couldn't find good documentation / tutorials online.

Edit:

I make an image hoping to explain more. (http://i45.tinypic.com/33epowi.png)
VM 2 and VM 5 should be in vlan 3 (maybe untagged)
VM 3 and VM 4 should be in vlan 4
there should be no communication being possible between the vlan's
The vlan should be configured in Xen so the client cannot change it.

in my current setup, only vm 2 and 5 can communicate, 3 and 4 are isolated from everything.

Best Answer

It turns out that the configuration on the cisco was correct.

On of the VM's I used for testing had a corrupted xen tools install, causing the network drivers of the internal vlan to fail. After I installed a new vm, everything worked as it should.

Related Solutions

Vlan Tagging at Access Port in Switch

switchport trunk encapsulation dot1q does not apply to access mode ports.

Vlan Tags are only pushed on the packet if it comes in untagged and egresses a trunk port; otherwise, the packet's vlan is simply tracked internally in the switch. Packets ingress to an access vlan port are tagged with that same vlan on the trunk port. The only exception is a packet that is on the trunk port's native vlan (default, vlan 1 on Cisco switches)

This answer on stackoverflow should clarify

Cisco – VLAN trunking between Juniper EX -> Cisco Catalyst -> and Cisco Router

You stated that ports 3 and 42 were configured on the Catalyst switch, but then provided configurations for ports 46 and 48. The configuration you posted for port 46 should be applied to port 3 that connects to the EX2200. Your router's connection is unchanged, so hopefully we can assume that configuration is fine.

Now, on the EX2200, the following lines of code would be appropriate to do the following:

ge-0/0/0 - trunk allowing the same vlans as defined above on port 46

ge-0/0/6 - access port on VLAN80

set vlans vlan80 vlan-id 80
set vlans vlan82 vlan-id 82
set vlans vlan83 vlan-id 83
set vlans vlan93 vlan-id 93
set vlans vlan289 vlan-id 289
set interfaces ge-0/0/0 description uplink-to-catalyst 
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vlan80
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vlan82
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vlan83
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vlan93
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vlan289
set interfaces ge-0/0/6 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/6 unit 0 family ethernet-switching vlan members vlan80

Some other suggestions for you:

1) Turn on LLDP on your switch so you can do a show lldp neighbors and see where your connections go.

2) Don't use RSTP for spanning tree on the juniper switch, it doesn't play nice with Cisco that well, use VSTP instead. If you end up with a ton of vlans, you might even need to use MSTP.

3) Turn off chassis alarm for the management ethernet if you're not using it.

On the EX2200:

delete protocols rstp
set protocols vstp vlan all bridge-priority 4k
set protocols lldp interface all
set chassis alarm management-ethernet link-down ignore

On the Catalyst (if it supports it)

lldp run

Related Topic