In article , AcCeSsDeNiEd wrote: :Hi have a switch called A on level/floor A. :Some of it's ports are directly connected to some of our servers and end-users.
:Now, we are also branching out to the floor below us. :I figured to cut costs/time we will uplink a single port from switch A to another Swtich called 'B' :located in floor B.
:Question is, will the performace/speed of users in floor B be slow in accessing the servers on :switch B? Will it result in users B having to share the bandwidth of the single uplink? (e.g :100mbits/100 users)?
Will everything be in the same VLAN? Will everything be in the same IP subnet? If the answer to both is Yes, then the users on switch B will not need to any of the bandwidth of the uplink when they are connecting to servers that are also on switch B. Similarily, the users on switch A will not need to use any of the bandwidth of the uplink when they are connecting to servers that are also on switch A.
If you have users on switch B who are connecting to systems on switch A, or users on switch A who are connecting to servers on switch B, or if different subnets or VLANs are involved and there is only one router (attached to either one of the switches), then all the active connections will share the single link. Whether that is a problem or not will depend upon how much traffic is going over the link.
There are a couple oi issues of varying importance to keep in mind:
- If your users are all using the same nameserver, then the DNS traffic will have to cross the uplink for one of the two groups. Once the IP of the destination system has been determined, user traffic will only have to cross the uplink to get to the appropriate server if the server is on the other floor from the user.
- If you are using NETBIOS, then you should be aware that NETBIOS uses broadcasts, and those broadcasts are going to cross the uplink. Broadcasts are an important part of NETBIOS resource locking, so you can't just filter the broadcasts without unwanted effects. [Well, without -more- unwanted effects, considering it is NETBIOS we're talking about.]
- Internet traffic is going to end up crossing the uplink for one of the two floors, depending where your WAN router is.
- If your filesystem backup device is on the other floor than the device being backed up, then the backup traffic will cross the uplink. Backups can often be automatically scheduled for hours when users won't be working, and so would not interfere with user traffic, but if you have any kind of decent backup device, your backup speeds are going to be limited by the speed of the network. If you have large filesystems, then you might find [as we do] that -user- traffic may rarely need more than the equivilent of 10 Mb/s, but that server-to-server traffic, or especially backups will use the full available bandwidth of the uplink for long periods (generating lots of alarms on whatever program you are using to monitor the health of your network...)