Accepted Solutions
Hi Scott,
You had some questions, which I have copied in red.:
1. Will the SG-200 allow you to trunk multiple VLANS to another switch? Absolutely
2. If it does - how? I have been through the documentation and it doesn't explicitly mention 'multiple' VLANS with LAG.
I have attached the Admin guide. The rules for LAG are defined at the bottom of page 82 of the attached document.
The 200 series supports four LAGs or in other words four Link aggregagted groups.
3. Is trunking possible through one LAG (say 6 ports) which passes all VLANS on the switch? Yes as the Admin guide suggests of page 83 , "
Assign up to eight active member ports to the static LAG"
So the primary question is whether what I want to achieve is possible on this switch. The reason I am trying to do this is of course redundancy. Carrying a VLAN over two switches is better. I just need to trunk properly between these.
I personally prefer to trunk over lags a different way, especially since you are only trying to achieve redundancy and higher aggregated bandwidths between switches. This is also relevant to the 300 series as the 300 series product is just a more feature rich product.
You want to ;"I would like to trunk between the VLANS using LAG with LACP. For example Switch A ports 1-22 are VLAN 1 and then 23-24 is the trunking for this. 25-34 is VLAN2 and trunking is 35-36. VLAN 3 is 37-48 and trunking 49-50. I seemed to be able to get VLAN 1, the default, trunking but not VLAN 2."
What about using the higher number ports for uplinking between switches, I have no particular reason for using these ports except they are on the right side of the switch.
Switch A Switch B
ports ports
vlan 1 1-24,47-48 1-24,47-48
vlan2 25-34 25-34
vlan3 35-46 35-46
LAG ports 49-50 49-50
The advantage of this is that now you have two ports load balancing traffic between the two 200 series switches. I could have more if i want, but i want to keep my example simple.
Create a Static LAG, by the sound of it you've done this already.
I just used my 300 series (SF300-48p)switch as a demo, as i don't have a 200 series switch. Configuration should just about be just about identical. In my case I have four GiG ports GE1 to GE4. I will use GE1 and GE2 as my two members of a LAG group 1. Might sound a bit confusing , but follow along below.
Added two ports to the LAG, note in the example below GE1 and GE2 are not connected to another switch , so they showup as standby ports;
Also my 300 series switch supports eight LAG groups, hence the numbers 1 to 8 as shown in subsequent screen captures.
Now that my LAG is created, you will note in the screen capture below that, VLAN1 is added automatically to LAG 1 as untagged frames.
Note: the circled Item, I selected LAG from that drop down menu and then clicked Go.
Note: 1 in the red rectangular box represents LAG group 1, which is made up of GE1 and GE2
Now I add VLAN 2 to the LAG group 1 by selecting VLAN 2 then selected LAG and then clicked go, the following screen came up.
I clicked on the tagged radio button in the rectangle above, to allow VLAN 2 to send tagged ethernet frames over the LAG group 1.
And so on , for other VLANs i migth have.
My methodology or train of thought, was to allow vlan1 to just send untagged frames over the LAG group 1, but any other subsequent VLANs will be tagged over the LAG group 1.
You should be able to do exactly the same thing on the other 200 series switch.
in my example I then just grab a couple of CAT6 or CAT5e cables and connect GE1 on one 200 series switch to Ge1 on the other 200 series switch
I then connect GE2 on one 200 series switch to Ge2 on the other 200 series switch.
Now I have Link aggregation and load balancing working between switches.
Hope this helps
regards Dave
Hi Scott,
You had some questions, which I have copied in red.:
1. Will the SG-200 allow you to trunk multiple VLANS to another switch? Absolutely
2. If it does - how? I have been through the documentation and it doesn't explicitly mention 'multiple' VLANS with LAG.
I have attached the Admin guide. The rules for LAG are defined at the bottom of page 82 of the attached document.
The 200 series supports four LAGs or in other words four Link aggregagted groups.
3. Is trunking possible through one LAG (say 6 ports) which passes all VLANS on the switch? Yes as the Admin guide suggests of page 83 , "
Assign up to eight active member ports to the static LAG"
So the primary question is whether what I want to achieve is possible on this switch. The reason I am trying to do this is of course redundancy. Carrying a VLAN over two switches is better. I just need to trunk properly between these.
I personally prefer to trunk over lags a different way, especially since you are only trying to achieve redundancy and higher aggregated bandwidths between switches. This is also relevant to the 300 series as the 300 series product is just a more feature rich product.
You want to ;"I would like to trunk between the VLANS using LAG with LACP. For example Switch A ports 1-22 are VLAN 1 and then 23-24 is the trunking for this. 25-34 is VLAN2 and trunking is 35-36. VLAN 3 is 37-48 and trunking 49-50. I seemed to be able to get VLAN 1, the default, trunking but not VLAN 2."
What about using the higher number ports for uplinking between switches, I have no particular reason for using these ports except they are on the right side of the switch.
Switch A Switch B
ports ports
vlan 1 1-24,47-48 1-24,47-48
vlan2 25-34 25-34
vlan3 35-46 35-46
LAG ports 49-50 49-50
The advantage of this is that now you have two ports load balancing traffic between the two 200 series switches. I could have more if i want, but i want to keep my example simple.
Create a Static LAG, by the sound of it you've done this already.
I just used my 300 series (SF300-48p)switch as a demo, as i don't have a 200 series switch. Configuration should just about be just about identical. In my case I have four GiG ports GE1 to GE4. I will use GE1 and GE2 as my two members of a LAG group 1. Might sound a bit confusing , but follow along below.
Added two ports to the LAG, note in the example below GE1 and GE2 are not connected to another switch , so they showup as standby ports;
Also my 300 series switch supports eight LAG groups, hence the numbers 1 to 8 as shown in subsequent screen captures.
Now that my LAG is created, you will note in the screen capture below that, VLAN1 is added automatically to LAG 1 as untagged frames.
Note: the circled Item, I selected LAG from that drop down menu and then clicked Go.
Note: 1 in the red rectangular box represents LAG group 1, which is made up of GE1 and GE2
Now I add VLAN 2 to the LAG group 1 by selecting VLAN 2 then selected LAG and then clicked go, the following screen came up.
I clicked on the tagged radio button in the rectangle above, to allow VLAN 2 to send tagged ethernet frames over the LAG group 1.
And so on , for other VLANs i migth have.
My methodology or train of thought, was to allow vlan1 to just send untagged frames over the LAG group 1, but any other subsequent VLANs will be tagged over the LAG group 1.
You should be able to do exactly the same thing on the other 200 series switch.
in my example I then just grab a couple of CAT6 or CAT5e cables and connect GE1 on one 200 series switch to Ge1 on the other 200 series switch
I then connect GE2 on one 200 series switch to Ge2 on the other 200 series switch.
Now I have Link aggregation and load balancing working between switches.
Hope this helps
regards Dave
Hi Stephan,
Toms spot on, even though the Cat4948 is a real beast with lots of functionality built in, it does not supported STACKING between the 4948.
When you "stack" two or more switches together, like with the Sx500, 2960S, 3750X. ...all switches in a stack act as a single switch unit. The Cisco Stack provides a unified data plane, unified configuration, and single IP address management for a group of switches. .This then allows for adding a LAG between switches in a stack. So a LAG as shown below to a STACK of switches will work
If the CAT 4948 supported Stacking you could LAG a SG200 between the stacked switches, because a LAG group only works between one switch to another. With the case of a "stacking" switch, the switches in a stack appear/behave as one switch .
Since the 4948 doesn't support stacking, Tom is dead right, in your case you really have two distinct CAT4948 switches wired together.
If you then decide to link to each CAT4948 from the SG200 switch, but you will need Rapid Spanning tree running on the switches to block one of the GbE links from the SG200 or a loop will result. If spanning tree or the variant Rapid spanning tree isn't used a broadcast storm will surely result.
The bottom line is, LAG from the SG200 will not work to the CAT4948, the way you would like it to work..
regards Dave
