topic Port configuration in Switching

Port configuration

saquib.tandel — Thu, 07 Mar 2019 09:04:07 GMT

We got a Scenario and need advice

Port 4/1 on a catalyst switch 4506 was configured for vlan 55. Windows team needs to configure Virtual Machine on the same box and use different vlan for each VM. ( i,e - vlan 55,56,57 can be allowed to use on port 4/1 and communicate with all vlans )

Current Switch-config

vlan 55

name SDG

vlan 56

name IDG

vlan 57

name MDG

inter gigaEthernet 4/1

description connected to HyperV-server

switchport mode access

switchport access vlan 55

What i understand to allow more than one vlan the port should be configured as trunk ports. if the port is connected to a PC then configure it as an access port. On my scenario what should I configure the port.

Thanks

Re: Port configuration

Thotsaphon Lueangwattanaphong — Sat, 02 Jul 2011 13:24:16 GMT

Hi,

VM(NIC support) needs to do VLAN tagging(802.1Q) for you. What you have to do is as follows:

inter gigaEthernet 4/1

switchport trunk encapsulation dot1q

switchport mode trunk

HTH,

Toshi

Port configuration

jimmysands73_2 — Sat, 02 Jul 2011 14:51:53 GMT

Do most NIC do tagging? I was always under the impression that NICs cant tag, that falls on the responsibility of the switch. And another question, by tagging we are telling the upstream switch which MAC address to assocatite to what port and what VLAN that MAC is tied to right?

Thanks,

Jimmy

Port configuration

Reza Sharifi — Sat, 02 Jul 2011 18:06:20 GMT

It it mostly done in a VM environments, where you have multiple NICs team together with multiple vlans. It is called "virtual switch tagging". ESX for example supports only dot1q.

HTH

Reza

Re: Port configuration

Thotsaphon Lueangwattanaphong — Sat, 02 Jul 2011 18:48:24 GMT

Hi Jimmy,

You may think of you have one phisical server that has one physical NIC. You would like to have multiple os/applications on that server. I'd call each OS/Application as guest. Let's say you would like to have 3 guests(virtual machines) on that server. You want to assign a vlan for each guest. You now need to have 3 networks/VLANs on that server. VM can create virtual NICs. You now have 3 virtual NICs for 3 guests on that server. Well, VM can also create a virtual switch. Yes,its all in software. Lets conclude what you already have in software.

1. 1 virtual switch.

2. 3 virtual NICs. 3 networks. 3 vlans. for 3 guests(OS/Applications)

3. Think of connecting 3 virtual NICs to a virtual switch. And assign a vlan to each virtual NIC. Let's say we create vlan 10,20 and 30.

4. Time to think of physical interface (real NIC on the server). You can think of we use a physical NIC as an uplink connected/bound to the virtual switch. Well, we want to carry 3 vlans out of the physical NIC to the network environment(Trunk Port). That's why we need a physical NIC to support VLAN tagging(802.1q).

HTH,

Toshi

Port configuration

jimmysands73_2 — Sat, 02 Jul 2011 23:52:54 GMT

Excellent description, thank you!!!

Re: Port configuration

tmwalsh — Sun, 03 Jul 2011 12:42:49 GMT

Do this all the time, basically need to set up a trunk between the server and the access switch. You'll want to use 802.1Q for the trunk and at least in our case prune the unwanted vlans.

Server nics are capable of teaming in this day and age. Which Hypervisor are you using? Xen, Hyper-v, ESX or some other flavor? You'll want to look at their documentation to determine specific steps needed.

Also, if your using HP Proliant Servers with NIC Teaming with Hyper-v you'll want to look at the sequence for installing hyper-v and the teaming agents. The gist is that the teaming needs to be installed after hyper-v for the vlans to work properly. If you built the server using the HP SmartStart CD you'll need to uninstall both hyper-v and the teaming parts.

Promiscuous mode is also sometimes needed to get all the vlans to be seen.

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