Connecting stacked switches (SGE2010)

Hi there,
This may seem like a basic question to many of you, but I'm finding it hard to discover any relevant information on the topic.
I have 4 SGE2010P switches stacked together:
What is the best way to create a faster link between the switches? I need more than 1Gbps across them, and I'm not sure of the best way to do this without risking a broadcast storm. I'd preferably like to be able to use some sort of LACP/Etherchannel between Switch 4 and any of the other switches.
Thanks in advance,
Ben.

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If it's performance you seek, change your daisy chain topology to a star configuration, i.e. one switch has direct links to the other 3. If you really believe you need more bandwidth, if the switches support it, you could also make some or all the direct links Etherchannel links. (Insure your hashing algorithm, if configurable, is suitable for your traffic flows.)
Assuming your switches also support STP, for redundancy, in the star configuration, you can interconnect two of your leaf switches (and configure star root to be logical root).
BTW, neither a star topology, or your shown (redundant - physical ring) daisy chain topology have much to do with broadcast storms.

Similar Messages

2960x - stack cables connected while switches power on. SFP ports - status unknown

Connected 2960x uplink using SFP ports both stacks and all 4 ports worked good.
Remote tech connected last stack cable between first and last switch, in 2 different 2960x stacks of switches, while switches were powered on. A longer stack cable was needed. 3 of 4 SFP ports did stopped communicating.
One stack SFP stayed up in switch 2, not master. Completed reload - other SPF connected in switch 4/0/52
Second stack no connection on either SFP, remote tech power cycled switches.
After power cycle one SFP worked in Master 1/0/52, other switches SFP ports show "unknown" when inserting SFP.
Configured port 48 on stack with issue and connected second uplink just fine.
Has anyone experienced this with the SFP's?
- GLC-T P/N 30-1410-03
Looking for documentation on reccommending procedure for connecting stack cables while switches should be powered off or not.
Thanks,

Opened Cisco TAC case. the following bug was found.
the two different HBRN's below require 2 different IOS and they cannot be in same stack.
https://tools.cisco.com/bugsearch/bug/CSCur56395
switch#sh ver | s Hardware Board
Hardware Board Revision Number : 0x05
switch#remote command 2 sh ver | s Hardware Board
Switch : 2 :------------ Hardware Board Revision Number : 0x05
switch#remote command 3 sh ver | s Hardware Board
Switch : 3 : ------------ Hardware Board Revision Number : 0x12
switch#remote command 4 sh ver | s Hardware Board
Switch : 4 :------------Hardware Board Revision Number : 0x12
From Cisco.
Developers have recommended to upgrade the IOS version of switches with a Hardware Board revision Number below 0x10 to the release 15.0(2.0).EX5ES. this is the one attached to this email and should be applied to switch 1 and 2.
For switches with a Hardware Board revision Number above 0x10 to the release 152-2.4.E1ES, which I will send you right away. This should be done on switch 3 and 4.
Now, If you load the engineering special, you will need to do a full power-cycle (physically unplug the power and plug it back in for every single switch). A simple ‘reload’ will not resolve this.
The same must be done on Switch-0. For this stack you will only need to load the image attached to this email since all the Hardware Board revision Numbers are lower than 0x10.
done.

L2 stack switch - to end-user devices

Hi all,
I came across a design in my project today and realize that there are 3 x L2 stack switches which will be connecting to end-user computers.
According to the client, for end-user devices, he intend to just connect 1device/interface.
Q1) I am wondering, in this design, the only intention is to increase the number of interfaces/ports , am i right ? as there is only 1 physical cable for each connected device.
==========================================================================================
In the same design, there is 2 x L3 switches which are meant for core network connecting to servers computers. They are stacked as well.
In this case, etherchannels are configured on the switches and servers which the 2 interfaces in 1 server are connecting to separate switches' interface in the stack.
Q2) Can I check, for this kind of switch stacking setup, are the etherchannels configure as active, active or it can be configure as active,passive ? or it is switches and servers dependable ?
Regards,
Noob

Hi Reza,
Thanks for the reply.
Q1) I am wondering, in this design, the only intention is to increase the number of interfaces/ports , am i right ? as there is only 1 physical cable for each connected device.
That is correct. The end devices (printers, PCs, laptops) usually have one physical cable and you can only connect them to one switch, but sometimes for mission critical environments engineers deploy multiple switches in case one of them goes out for any reason.
What if in the event that 1 of the switch go down, as the switches are stacked, can i just plug out the cable @ interface let's say at switch1 fe0/1 and insert it into switch2 fe0/1 ? (provided it is not occupied)
Q2) Can I check, for this kind of switch stacking setup, are the etherchannels configure as active, active or it can be configure as active,passive ? or it is switches and servers dependable ?
If you issue "sh etherca summay" on the stack, it will show you the port number that are part of that etherchannel. As for active or passive, usually the switch is configured as active and servers as passive but you can also configure both sides as active.
Do you mean on the server side, only 1 port will be receiving/sending information, but on the switch side, each interface at each of the 2 switches is able to receive/send ?
Regards,
Noob

Using 37xx stack switch can I send snmp messages as syslog ?

In my environment, we are having cisco 37xx stack switches, I want to know is it possible to use the switch config to send snmp traps as syslog messages to the Syslog-server.
In our case, we are using siem which has the ability to process syslog messages from different networking switches. What specific event I'm after is related to bandwidth utilization of the interface. It would have been great if there was existing syslog-event for exceeded bandwidth or increase in bandwidth beyond certain bps rate. The only place such information can be obtained is from snmp, but the siem station doesn't understand snmp, So I hope there are some setting which allows the conversion of snmp traps to syslog msg to be forwarded to destination.
Thanks.

The iPad cannot use your Android phone number at all so it will not in any way be associated with the device or your Apple ID. You will be using your Apple ID email address as your connect address to use Messages. If you want to look at it this way, your iPad/iMessages will be associated with your Apple account/Apple ID, not with the Android phone number.
Where some users get into problems is if they go from an iPhone number to an Android phone number. That is not what you are doing.

What is a stacked switch?

Hi,
Can anyone explain what is a stacked switch and what kind of switches can be stacked and why the switched need to be stacked and how they work.
Any links that I can go through to get the details.
Thanks in Advance,
Shyam

Hi
When you talk about stacking the cisco switches, there are two techniques
gigastack :- In this you connect all the switches uplink with gigabit stack GBIC.
guru prasad has given one cisco url for that.
and all the switches that support stackwise technology are now end of sale.
stackwise and stackwise plus :-
Cisco StackWise technology unites up to nine individual Cisco Catalyst 3750 switches into a single logical unit, using special stack interconnect cables and stacking software. The stack behaves as a single switching unit that is managed by a master switch elected from one of the member switches. The master switch automatically creates and updates all the switching and optional routing tables. A working stack can accept new members or delete old ones without service interruption.
http://www.cisco.com/en/US/products/hw/switches/ps5023/products_white_paper09186a00801b096a.shtml
now we can say that we have only one stacking option available that is of stackwise as all model which supported gigstack are now end os sale.
HTH
rate if it helped
rgds
rajat

Connect additional switch to existing switch, receiving vlan mismatch, also want to configure same VLAN's

Hello! I have a network in with a i have a switch stack configured for voice and data. Particularly, both are configured to pass over the same port.
I want to add a temporary switch (different model) to the network and configure it the same way. In particular, I want to see that I can set up the voice/data VLAN's on this new switch and test to confirm all is working. I need an uplink though back to the original switches so that this new switch can get a proper connection.
When I connect the new switch in, I can't seem to get an IP and the CLI keeps showing a "Native VLAN mismatch error" and shows the hostname of the original switch.
So my questions are:
How can I add this temporary switch to the existing switch to get a connection, not as another stacked switch?
How can I configure the voice/data VLAN's on the switch so as to be able to test the voice/data traffic over the same port?

Hi! Yes I did change the native vlan for that particular port on "Sw2" (New switch) to match "Sw1" (existing switch). The Sw2 port shows native vlan inactive though.
Below is an output from them on that port.
(SW1)
Name: Gi3/0/5
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 100 (VLAN0100)
Administrative Native VLAN tagging: enabled
Voice VLAN: 10 (VLAN0010)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
SW2
Name: Gi3/0/5
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 100 (Inactive)
Administrative Native VLAN tagging: enabled
Voice VLAN: 10 (Voice)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

LMS and stacking switches

Hi everyone!
I was having a conversation with a friend and he assured that the LMS is stacking switches with up to 09 switches.
Anyone know if this is true? For all I know this is only done through the special interface stack (as in 3750 and 2960S).

LMS (and Cisco Network Assistant) manages Cisco switch stacks. And, yes, a stack is up to 9 switches.
I'm not sure what you're asking, though. Stacks are built by virtue of physically connecting the StackWise cables and that is independent of what, if anything, is used for network management.

Performance of stacked switch

I'm installing a stack of 3x 3750G switches, which are inter-connected w/ StackWise cables.
Are stacked switches truely act as one switch w/o any performance penalty if a packet has to traverse from one switch to another in the same stack?
Would it be better to arrange the ports together on the same switch if I know they'll mostly generate local traffice among themselves?
Another question I have is sould I try to distribute ports among the stacked switches as much as possible or is the stack really functioning as a unified stack??
For instance, I've got 3x 24-port 3750G's; thus a total of 72 ports. If I currently have only 24 objects (clients or switches), should I plug 8 in each switch or it doesn't make a difference if I plug all 24 objects into the same switch?

A customer asked me this exact question the other day....
The stack has an interconnect speed of 32G. Thus a packet coming in from 1/0/1 going to 3/0/1 will hit the backplane on switch 1 (speed so high you can forget about it for all intents and purposes) traverse the 32G interconnect bus, across the backplane on switch 3 to the egress port. You can consider this almost identical to the 6500 series when using the "classic" series line cards (61xx series) which likewise share a 32G backplane bus.
I have tested this with IXIA gigabit traffic generators which blasted 20 Gig of traffic with 50000 flows across the switch stack. The boxes were solid as a rock. 20Gig is rather a lot of traffic.... !!!
The only occassion when you might have a problem with this architecture is if you have multi gigabit traffic crossing the switch stack that requires QOS priority on an already heavily utilised stack. In that case you could possibly get contention for the stacking bus (unless there is a way of prioritising the traffic gaining access to the stacking bus???? There hasn't been in the past). Cisco's answer to that would be twofold.
1.If you required such traffic patterns with such heavy traffic and QOS requirements then you should be using a 6500 series switch with high end interface blades.
2.That the 3750 supports ingress QOS to precisely address the problem of overloading the switch fabric.
Best regards,
Steve

3750 Stack Switch Issue

Hi
I have Stack of 7 3750 Switches. In that Switch 1 is master with 15 Priority and other switches are Member but because of some reason switch 1 rebooted and then Switch 2 becomes Master because it’s having 14 Priority.
We have 2 uplinks which connected on switch 1 (1/1/1) and switch 6 (6/1/1) Tengig port. Also we have 4 AP connected on switch 6.
So we observed that the Switch 1 came up and after that 3 AP is disconnected from WLC. if we disconnect the uplink port on Switch 1 (1/1/1) AP will connect the WLC and using uplink 6/1/1 but if we connect uplink port 1/1/1 and disconnect the uplink port 6/1/1 all 4 AP will disconnect from Network.
We try to connect the Uplink 1/1/1 to Switch 1 other port 1/1/2 but face the same issue. So we reconnect the port 6/1/1 and used the same link which connect on 1/1/1 to switch 7 (7/1/1) and AP will connect on WLC. So as per this troubleshooting we thought some issue with Network Module or Switch of Switch1.
So we Swap the Network module between Switch1 and Switch7 and connect the uplink on 1/1/1 but face the same issue and if we connect the same uplink on Switch 7 Ap connect to WLC.
So we thought that Switch is having issue. But before raising an RMA for Switch we observer 1 more thing that. Earlier that when the Switch 1 is Master all 4 AP's connected to WLC and working fine but when the Switch1 became rebooted and Switch2 became Master issue started. So we rebooted the Switch 2 and make switch master and found that while connecting on port 1/1/1 of Switch port AP's are able to connect to WLC and Issue resolved.
So I wants to know that is there any requirement that If the high priority switch rebooted and after came up it should not be Master then connected uplink will not work.
Also let us know what’s happen if the high priority switch came up in network. Means it’s will became Master or Menber.

Just now i Found one bug which is matching on our issue.
3750x stack fails to update ARP table after reboot causing traffic loss
BUG ID:-CSCtz98066
Symptoms: When the master switch (Switch A) is reloaded or loses power and
rejoins the stack as a member switch, any traffic stream being sent through
Switch A is unable to be received by the destination because the newly joined
member is not able to establish an ARP entry for the next hop router/switch.
Debugs confirm that Switch A does not send a GARP/ARP for the next hop, though
traffic continues to be sent to the switch.
Conditions: The symptom is observed when only Switch A has a physical
connection between the source and destination router/L3 switch. The newly
elected master (Switch B) does not.
Workaround: Ping destination from Switch A, forcing ARP request/response.
Also affected version is 12.2(58)SE and15.0(1)SE2 and we are using IOS 12.2(58)SE.
So we are going to upgrade the devices by this weekend with IOS 15.0(2)SE5.
Will update you once we upgraded the switches.

ASA Redundant interfaces with stack switches

Hi All,
we have two ASA 5510 connected in failover, and a pair of cisco 2960s switch connected in stack.
Currently one interface of primary ASA is terminated on switch1 and a interface from standby is connected to switch2 as Inside, and switch1 and switch2 are in stack.
for redundancy purpose i want to use multiple interfaces of ASA for inside , so first i thought to use etherchannel , but it has a limitation that , it cannot be terminated on stack switch(as per cisco document http://www.cisco.com/en/US/docs/security/asa/asa91/configuration/general/interface_start.html ).
So my question is :
1. can we use redundant interface feature where 2 physical interfaces combined to a redundant interface (eg interface redundant 1) for inside redundancy purpose.
2. Can these ports from primary/standby ASA terminated on stack switches (2960s), will this work (if the switch with active port goes down, will the other port take over in the redundant interface with the other switch).
I have attached the nw diagram,
Regards,
Ashraf

Hello Ashraf,
1. can we use redundant interface feature where 2 physical interfaces combined to a redundant interface (eg interface redundant 1) for inside redundancy purpose.
Sure, you can. That's the whole purpose of the feature.
2. Can these ports from primary/standby ASA terminated on stack switches (2960s), will this work (if the switch with active port goes down, will the other port take over in the redundant interface with the other switch).
It would make sense if that happens, as the status of the interface will be on a different state than up/up so failover to the other interface will be triggered,
Regards,
Julio

Etherchannel between stack switches[3750] and standalone switch[3560]

Hi,
I have 2*3750 switches in stack as core and 1*3560 switch in access layer. I want to enable ether channel between stack switch[3750A & 3750B] and 3560 switches.
Have connected 2 links from 3560 switch to stack switch, one link to 3750A and other link to 3750B. Will it work in this way as per my requirement?
or i should enabled stacking on 3560 switch too and configure cross-stack ether channel between 3750 stack and 3560 stack. i refered few cisco documents, but the cross stack etherchannel configuration example has 3750 at both end stacks.
Rgds...
VikramS

Hi,
This should work fine as per you set up, the 3750 stack will be acting as one switch, which means that the ether-channel configuration should be straight forward. There is no need to stack the 3560 for this to work, also the 3560 are not stackable.
Hope this helps.

Failed while creating virtual Ethernet switch. Failed to connect Ethernet switch port

Hello Folks
I am completely stuck with the configuration of my virtual networks. I have one logical switch left to add to one of my Hyper-V 2012 R2 hosts when I started getting the error below when I try to add logical switches to either Hyper-V Host. I have been using
the document. 'Hybrid Cloud with NVGRE (Cloud OS)' to implement the virtual networking. Basically using the exact configuration that is in the document. I have added the PA Logical Network and the Network adapters and added the logical switch for it to my
hyper-v 2012 R2 host and everything was fine. I am now trying to add my ISCSI Logical Switch to the host and this is the error I get. My other Hyper-V host I get this error for any logical switch I am trying to add. Can someone help me with this error. I haven't
been able to find any information about it.
Also a some quick info on tracing an error like this so I can figure out what is causing it.
Thsi is my configuration so far
So as far as I know everything is peachy untill the error below. Dead stop now
Error (12700)
VMM cannot complete the host operation on the 08-NY-VHOST01.accounts.ccac-ont.ca server because of the error: Failed while creating virtual Ethernet switch.
Failed to connect Ethernet switch port (switch name = '******', port name = '88C16766-ED02-4AC0-8CD7-660AC9D424DD', adapter GUID = '{FAF431D8-0124-4E40-BB3B-9234BAA02973}'): The system cannot find the file specified. (0x80070002).
Unknown error (0x800b)
Thank you for your time
Christopher
Christopher Scannell

notice your GUID? you may want to consider ensuring that is the same GUID associated in your database. Sometimes during data corruption theres a smidge of a chance your sql database kind of either pulls old guids esp if this was reverted to snapshot
without it being powered off etc.
I would try that first. then i would consider if you get to configure that with your current liscense associated with the host. I would need way more info to help any further

Connecting a Switch to the E4200

Have a Linksys E4200 router located in my basement and I am experiencing a puzzling wired connectivity issue as follows:
Port 1 on the router is for my study, I have no problem getting connection regardless if I use my study's Ethernet jack or if I run a 5 ft. cable (hereinafter THE CABLE) from the router’s port 1 to my laptop (i.e., cabling does not make a difference).
I then connect to router port 1 an EZXS55W Linksys switch (using port 1 on the switch and THE CABLE) and then connect my laptop to port 2 on the switch using a second cable. I am unable to connect to the network/internet even after rebooting both the cable modem and router.
I then reconnect my study to port 1 on the router, I go to my study and connect the study’s Ethernet jack using THE CABLE to port 1 on the switch and using a second cable from port 2 on the switch to my laptop. …. I get an network/internet connection immediately !
Can someone assist with this puzzle ? Has anyone seen this before ? FYI, I have had the exact problem with switches EZXS88W and SE2500 (no longer own this).
Thanks,
Zach
Solved!
Go to Solution.

Sorry but the description of the problem is quite vague and a bit confusing.
To get the switch working properly make sure the router is connected to the uplink port of the switch. Take note: When Uplink port is used, the port adjacent to it becomes inactive (port5) because they are shared. Switches are really pass-through devices so nothing is to be configured.
"Also be aware that on the outside of the box for the EZXS88W switch, there is a picture showing a "Broadband Router" connected to port #1 of the switch. The Uplink is shown as being connected to another switch." The picture shown outside the box refers to how you could connect the switch to other networking devices; router, switch or a hub to expand your network.
Check out these links, hope it could help;
Connecting a Linksys switch to a router
http://homekb.cisco.com/Cisco2/ukp.aspx?pid=93&vw=1&articleid=22996
Checking if the router is working properly when connected to a switch
http://homekb.cisco.com/Cisco2/ukp.aspx?pid=93&vw=1&articleid=22996

Hi, I recently got myself an apple iphone 5s (factory unlocked) phone from the US. However on using the same in India with Vodafone, i am facing a problem where the connectivity keeps switching to EDGE most of the time. Any solutions??

Hi,
I recently got myself an apple iphone 5s (factory unlocked) phone from the US. However on using the same in India with Vodafone, i am facing a problem where the connectivity keeps switching to EDGE most of the time. I have a 3G plan but most of the time it switches automatically to EDGE. Thats when i have to either switch Airplane mode - On/Off and then it acts normal. Any permanant solutions to fix this problem?

Return the iPhone personally or via friend/relative/co-worker who is in
the US. The warranty is valid only in the country of original purchase - the USA
in this case. Apple will not accept international shipments for evaluation nor
will Apple ship out of the country after repair/replacement.
How did the iPhone from the US get to you in India? Reverse that process to
get it back to the US so someone can take it into Apple.

Networking Best Practices - Connecting Two Switches

Connecting two switches together is an easy task, which makes it so frustrating when it doesn’t work. Here we will outline a basic scenario of connecting two switches and achieving connectivity. In these scenarios we will be using commands and settings that will work for most modern PowerConnect switches. However this does not cover all possible scenarios and the commands may differ slightly from switch to switch.
For instance, in most cases you can use General or Trunk mode when connecting two switches. However, on the PowerConnect 62xx series switches, you must use General mode if you want to allow management traffic onto the switch over the PVID. If you use Trunk mode, you will not have the default VLAN on those ports. The ports will only allow tagged traffic.
For more details on the difference between Access, General, and Trunk modes, follow this link.
http://en.community.dell.com/support-forums/network-switches/f/866/p/19445142/20089157.aspx#20089157
It is always a good idea to have the user and CLI guide for your switch, to reference any possible changes in command syntax.
http://support.dell.com/support/edocs/network/
Layer 2
Layer 2 switches operate at the data link layer of the OSI model. Layer 2 is responsible for error checking and transmitting data across the physical media. MAC addressing sources and destination protocols are layer 2 protocols. Layer 2 switches use the MAC address of data packets to determine where those packets should go. It learns the MAC addresses of all devices and creates a segment/forwarding table.
When a switch receives a frame with a destination address that isn't in its forwarding table, the switch forwards the frame to all other ports. If the destination machine responds to the server, the switch will listen to the reply and learn which port the destination machine is attached to. It then adds that MAC address to the forwarding table.
The Dell PowerConnect Layer 2 switches have ports that all operate in VLAN 1 by default. If it is acceptable to have all traffic on the same broadcast domain, then you can simply leave the default alone, connect the two switches and traffic will flow.
If you do not want all traffic on the same broadcast domain, then we need to look at adding additional broadcast domains through the use of VLANs.
We will use 3 VLANs for the following scenario.
VLAN 1=Management
VLAN 2=Client
VLAN 3=Server
To create these VLANs we do the following commands (VLAN 1 is already created by default)
console(config)# vlan database
console(config-vlan)# VLAN 2
console(config-vlan)# VLAN 3
console(config-vlan)# exit
We can then name the VLANs to help keep things organized.
console(config)# interface vlan 2
console(config-vlan)# name Client
console(config-vlan)# exit
console(config)# interface vlan 3
console(config-vlan)# name Server
console(config-vlan)# exit
Once we have the VLANs created we can place a device in that VLAN by placing the port it plugs into, in access mode for the specific VLAN.
So we have a workstation on port e2 we want to be placed in VLAN 2, we would issue the following commands.
console(config)# interface ethernet 1/e2
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 2
console(config-if)# exit
The next port plugs into a server on port e3 we want on VLAN 3, we would issue these commands.
console(config)# interface ethernet 1/e3
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 3
console(config-if)# exit
For the ports connecting the two switches together, we place the ports in trunk mode and specify the native VLAN and allowed VLANs.
For the port e1 that connect the two switches to each other would be configured like this.
console(config)# interface ethernet 1/e1
console(config-if)# switchport mode general
console(config-if)# switchport general allowed vlan add 2,3 tagged
console(config-if)# switchport general pvid 1
console(config-if)# exit
Once these VLANs and port settings are made on both switches. A server connected to switch A on VLAN 3 should be able to communicate with another Server connected to switch B that is also in VLAN 3. Without the use of a router the devices in VLAN 3 will not be able to communicate with devices that are outside of their broadcast domain (i.e. VLAN 2 devices could not reach VLAN 3 devices)
Layer 3 + Layer 2
Until recently, routers were the only devices capable of layer 3 protocols. Switches capable of routing are now available and in widespread use. In most cases we will connect our layer 2 switches to a Layer 3 capable switch to perform our routing for us.
On the layer 3 switches we will use the same VLANs and setup that we did with the layer 2 switches. Then we will add to the configuration.
We can assign an IP address to each switch with the following command.
Switch A
console(config)#ip address 172.16.1.1 255.255.255.0
Switch B
console(config)#ip address 172.16.2.1 255.255.255.0
Then we will enable routing only on Switch A
console(config)# ip routing
Switch A we assign an IP address to VLAN 2 and enabling routing on the VLAN.
console(config)# interface vlan 2
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.20.1 255.255.255.0
console(config-if-vlan2)# exit
Switch A we assign an IP address to VLAN 3 and enabling routing on the VLAN.
console(config)# interface vlan 3
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.30.1 255.255.255.0
console(config-if-vlan2)# exit
On both switch A and switch B we will keep things simple and use interface 1/e1 for the connection between each switch. Setting both switches 1/e1 to general mode, allowing the additional VLAN 2,3, and keeping the PVID of 1.
console(config)# interface ethernet 1/e1
console(config-if)# switchport mode general
console(config-if)# switchport general allowed vlan add 2,3 tagged
console(config-if)# switchport general pvid 1
console(config-if)# exit
We will have one client computer connect to switch A on port 1/e2 and one client connect to switch B on port 1/e2. These ports will be in access mode for VLAN 2, and the config should look like this on both switches.
console(config)# interface ethernet 1/e2
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 2
console(config-if)# exit
We will have another client computer connect to switch A on port 1/e3 and one client connect to switch B on port 1/e3. These ports will be in access mode for VLAN 3, and the config should look like this on both switches.
console(config)# interface ethernet 1/e3
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 3
console(config-if)# exit
On Clients connected to Switch A we will assign an IP address and gateway based on the VLAN they are in access mode for.
Client connected to access port for VLAN 2.
IP Address:172.16.20.11
Default Gateway:172.16.20.1
Client connected to access port for VLAN 3.
IP Address:172.16.30.11
Default Gateway:172.16.30.1
On Clients connected to Switch B we will assign an IP address and gateway based on the VLAN they are in access mode for.
Client connected to access port for VLAN 2.
IP Address:172.16.20.12
Default Gateway:172.16.20.1
Client connected to access port for VLAN 3.
IP Address:172.16.30.12
Default Gateway:172.16.30.1
External Connection
At some point we may want traffic to have an external connection. To do this we can create a new VLAN for our point to point connection from Switch A to our router. We will use VLAN 7 for this and assign an IP address.
console(config)# vlan database
console(config-vlan)# VLAN 7
console(config-vlan)# exit
console(config)# interface vlan 7
console(config-vlan)# name WAN
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 10.10.10.2 255.255.255.0
console(config-if-vlan2)# exit
On our router we will assign an IP address of 10.10.10.1
Then place the port connecting the switch and router into access mode for VLAN 7. In this case we use port e4.
console(config)# interface ethernet 1/e4
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 7
console(config-if)# exit
We will then need to put in a default route with the next hop as the router IP address. This allows the switch to know where to route traffic not destined for VLANs 2, 3, or 7.
console(config)#ip route 0.0.0.0 0.0.0.0 10.10.10.1
Next on the router we’ll need to add a route back so the router knows about the networks attached to switch A. Generally adding a static route on most routers is done with the following command:
ip route {Network} {Wildcard Mask} {Next Hop-IP}
In our case here are the 2 static routes we could use.
Ip route 172.16.20.0 0.0.0.255 10.10.10.2
Ip route 172.16.30.0 0.0.0.255 10.10.10.2
The routing that we enabled on Switch A will enable traffic from the other VLANs to traverse over port 1/e4 to the router, connecting us to external traffic. The routes we added to the router allow the traffic to flow back to the switch over port 1/e4.
Layer 3 + Layer 3
In some situations we have two switches, each setup to route for its own broadcast domain, which we want to connect together. In this situation we no longer have a need to use Trunk or General mode between the switches. Instead we can create a common VLAN that will be used for the connection between the two switches.
To create this VLAN we will run the following commands on both switch A and B
console(config)# vlan database
console(config-vlan)# vlan 6
console(config-vlan)# exit
console(config)# interface vlan 6
console(config-vlan)# name Connection
console(config-vlan)# exit
On switch A we assign an IP address to VLAN 6 and enable routing on the VLAN.
console(config)# interface vlan 6
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.60.1 255.255.255.0
console(config-if-vlan2)# exit
On switch B we assign an IP address to VLAN 6 and enable routing on the VLAN.
console(config)# interface vlan 6
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.60.2 255.255.255.0
console(config-if-vlan2)# exit
On both switch A and B we place the connecting ports into Access mode for VLAN 6.
console(config)# interface ethernet 1/e1
console(config-if)# switchport mode access
console(config-if)# switchport access vlan 6
console(config-if)# exit
We then need to make some changes to switch B now that it is layer 3 and not layer 2 and has its own broadcast domain.
We will enable routing on Switch B
console(config)# ip routing
What used to be VLAN 2 and 3 will now be VLAN 4 and 5 for our separate broadcast domains.
Switch B we assign an IP address to VLAN 4 and enabling routing on the VLAN.
console(config)# interface vlan 4
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.40.1 255.255.255.0
console(config-if-vlan2)# exit
Switch B we assign an IP address to VLAN 5 and enabling routing on the VLAN.
console(config)# interface vlan 5
console(config-if-vlan2)# Routing
console(config-if-vlan2)# ip address 172.16.50.1 255.255.255.0
console(config-if-vlan2)# exit
On Clients connected to Switch B we will assign an IP address and gateway based on the VLAN they are in access mode for.
Client connected to access port for VLAN 4.
IP Address:172.16.40.11
Default Gateway:172.16.40.1
Client connected to access port for VLAN 5.
IP Address:172.16.50.11
Default Gateway:172.16.50.1
The end result should look like this.
Troubleshooting
If we are having issues with connectivity, we may need to place some static routes in place to help traffic to the next hop in the network.
On switch A we configure a static route to help traffic to the next hop in the network, which is the router.
console(config)# ip route 0.0.0.0 0.0.0.0 10.10.10.1
The external router will also need a path defined back to all networks/VLANs.
To check the status of a port we can use the command. Show interfaces detail, this will help us see the port status. For example to check the status of port 48, we would run this command.
console# show interfaces detail ethernet 1/g48
To check routing paths:
console# show ip route
The IP address of the network for each VLAN should be listed as C – Connected. Then also a path or default route to your upstream router.
We can use basic ping commands from a client to help test where connectivity is dropping off at. By doing this we can narrow down where in the network to start troubleshooting.
-Ping from client to default gateway, being the VLAN the client is in access mode for. If this fails then we may need to double check our client settings making sure the proper IP and gateway are being used.
-Ping from client to the ip address of the switch the client plugs into. If this fails we may not have VLAN routing enabled on the VLAN the client is in.
-Ping from client to another client on same VLAN, same switch. If this fails we need to check on client settings, IP address and gateway.
-ping from client to another client on different VLAN, same switch. If this fails we need to double check the VLAN routing commands are in place.
-ping from client to the ip address of the next switch in the network. If this fails then check Trunk port configuration from switch to switch, ensuring the VLAN is added to the Trunk port.
-ping from client to another client on same VLAN, different switch. If this fails, check Trunk port settings.
-ping from client to another client on different VLAN, different switch. If this fails then check trunk settings and VLAN routing configuration.

Derek,
I tried to draw my prefered setup for this network configuration.
I would create a Team with the two 1 GBit NICs and use it for Domain, DNS, Backup and any SystemCenter Agents.
I would also Team the two 10 GBit NICs and than assign it to a Hyper-V Switch for the VMs. In Windows Server 2012 it is posible to create vNICs for the Management OS that use this Hyper-V Switch (Converged Network Design). I would create two vNICs SMB1
and SMB2 to use them for Cluster and Livemigration traffic with SMB Multichannel. If your storage system supports SMB Multichannel you can also use both as storage NICs (but this depends wich vendor you have).
Hope this helps.
Grüße/Regards Carsten Rachfahl | MVP Virtual Machine | MCT | MCITP | MCSA | CCA | Husband and Papa |
www.hyper-v-server.de | First German Gold Virtualisation Kompetenz Partner ---- If my answer is helpful please mark it as answer or press the green arrow.

Connecting stacked switches (SGE2010)

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