Use uplink port as access port 2960 1

[CDIV]

Dear all,

I have 2 SW 2960 ( 48 X 1G+ 4 Uplink SFP)

My question is: is it possible to use one uplink port sfp in trunk mode (to link between the 2 switches) and a second uplink SFP in access mode to connect it to a storage Server.

Thank you in advance for your help

 

[iggsterman]

You should be able to. It's just a port.

 

[ADB100]

Yes. There are no differences when configuring uplink ports or access ports. There may be some architecture differences internally - i.e. buffer space, ASIC connections etc. However you can apply the same configuration to a 10/100/1000 copper port as you can to a SFP port. If fibre isn't needed for your uplinks (i.e. the switch or router you are connecting to is closeby and copper will do) then we have lots of customers just using one of the copper ports as an uplink. We also have customers using the uplink SFP ports to connect individual hosts that are located more than 100m away and the only option is fibre and a media converter.

Andy

 

[CDIV]

Hello ,
Thank you for your help.
I follow your recommendation.
Now I'm using G1 1/0/49 as uplink trunk mode. And 1/0/50 in access mode to a storage Server dell R530.
And it work perfectly.

So I still not sure about linking one access port GE (SW A) vlan30 to another access port GE in SW B default
Vlan1.
Also if possible to help me to perform a bandwith speed test from computer 1 to the server.

Thank you in advance

Karim

 

[ADB100]

You can link the two switches together over access ports, however STP will treat the ports differently as STP will be running. You can also configure the ports as trunks if you want the same VLANs available on both switches. Just ensure your trunking configuration is the same on each side of the link.
For speed tests either copy a file of a known size, time it and do the math to work out the Mbps you are getting. You could also use something like IPERF to do raw speed testing but you would need IPERF on both the server and the client, plus if its Windows then IPERF isn't the best under Windows. A stright copy of a large file should give you a good indication of what speed you are getting.

Andy

 

[iggsterman]

Hello Andy, why would not STP be running and why would it treat the ports differently? I did not follow.

 

[ADB100]

By default unless you turn off spanning-tree (per VLAN) the switch sends BPDU's out each interface to build and negotiate the Spanning-Tree Topology - root, root ports etc. An end device doesn't usually run STP so a switch will detect this and consider it an 'edge' port. If you link two switches together then STP BPDU's are sent and they will work out who is the root for the STP and then put the ports in the relevant state. If you create a loop in the topoogy - i.e. you link the switches together with two cables then STP will disable one of them (put it into blocking state).

STP has been around for YEARS and has evolved somewhat from 802.1D to 802.1W (Rapid STP) and 802.1S (MST) as well as proprietary versions such as Cisco's default PVST & Rapid PVST. There are also tweaks vendors have added to get around default STP state timers. Your best bet would be to just have a read - Google is your friend here....

 

[iggsterman]

I know what STP is. I asked for the meaning of
"however STP will treat the ports differently as STP will be running"
1. Why wouldn't STP be running, per vlan or not, rapid or not?
2. Why would STP treat the ports "differently"? Same speed ports will have the same path costs.
I am not nit picking. I am trying to understand if three's something I am missing here.

 

[ADB100]

STP might not be running if it is disabled on the VLAN? The original poster didn't post any configurations so how do we know whether STP is running? We also don't know the software release so the default STP mode might not be PVST+ - it could be Rapid PVST+ which detects ports differently - i.e. P2p Edge ports, P2p ports etc.
Linking two switches together is different from linking a workstation to a switch as far as STP is concerned. There are a whole bunch of best practises that should ideally be followed here. However that's not what the original poster was asking.

 

[CDIV]

Thank you so much for your help.