Begginer question

[frl]

Hi,

we have a simple network of 2 servers and 25 clients. Now we have a 10Mb network with 3 10Mb 3Com non-manageable hubs.
We are upgrading the network to 100Mb. So we will replace the 3Com hubs with two Cisco Catalyst 2950T with 24 ports and EI.
Can someone get me some advice what to look for, how to set it up,etc... I don't have a lot of experience with manageable switches.
Thanks!

 

[SF18C]

I would start with

http://www.cisco.com/en/US/products/hw/switches/ps628/ps631/index.html

You haven't stated if you plan to use VLANS or what your WAN/Routing situation looks like so its hard to say. But basically if you do nothing other than turn them on and plug in your end systems they should switch packets with no major set up.

SF18C
CCNP, MCSE, A+, N+ & HPCC

"Tis better to die on your feet than live on your knees!"

 

[frl]

Thanks for your reply,

we connect to our WAN and Internet through a router. We will use switches just for our office behind the router. I am just interested in how you manage this manageable switches (software, browser?), because until now we used just the non manageable ones here in our location.
I heard you can do a lot of things with them, like monitor traffic per port or specify bandwidth per port. I am just wondering how difficult is to set up things like this?

 

[davemiller]

you will need to configure the switches each with an ip address in vlan1. you could browse to the switch, but this can be a denail of service risk. i telnet to all switches from a secure and designated host. you can also use the console ports since your lan is probably all in the same closet. i would avoid 3com. cisco is great ($500 for a 2950 24x10/100). dell may be worth a look. a switch doesn't come with the software to do trend analysis. that software is typically 3rd party and will reside on a server. the app will retrieve the switch stats via snmp. although with your lan size it might not be worth the cost/effort. your bottleneck is typcially your wan circuit/router.

 

[frl]

I installed the switches and they work OK. Have one question. How do you see/monitor the traffic on the port that is connected to the router through which we connect to internet.
I would basicly like to see what is our traffic to outside-internet. How do you do that on Cisco 2950T?

Thanks!

 

[baddos]

frl... For your environment, a simple crossover cable between the two switches should be enough. You might want to use port security or something down the road, but right now you should be good.

The only thing you really need to do is turn on spanning-tree portfast on every port (except the crossover cable ports).

To administer the switch plug your com port into the console port on the switch. The manual that comes with the switch will tell you all you need to know.

 

[frl]

I have the switches connected with the crossover cable allready. I can telnet to the switches for administration, so I think I don't need to go to console port.

I would like to know how can I (which commands) monitor the traffic on the specific port.

Thanks!

 

[NetEng631]

You can use Perl with NET::SNMP to poll the mibs or get a freeweare software like MRTG or others.

I know the 6500 support NetFlow I dont think any of the smaller switches do.

NetEng

 

[Syty]

Your router will support NetFlow if your IOS is great enough.

If you have a 3rd party "sniffer" and you are keeping all clients on VLAN1, then simply to to the interface that your "admin workstation" resides on and give the following commands.

interface f0/xx <----- Admin workstation Port
port monitor VLAN1

Due to collision domains, you will only see the broadcast traffic from all other ports if you do not turn on port monitoring.

Just look at it from the point of view that Your Port will monitor any other PORT in VLAN1, to include any traffic coming from/to your switch IP itself. Examples would include detecting anyone else trying to telnet your switch.

NOTE: Using a 3rd party sniffer will be getting A LOT! of traffic if you are not filtering and looking for specific traffic.

NetEng631 is on point for auditing traffic over time or establishing network management.

A stand alone sniffer is good for troubleshooting, etc...

Good Luck.

 

[frl]

Thanks for your replies guys!!

I downloaded and installed MRTG and tried it on an old router and it works fine.

I have problems runing it on the Cisco 2950T switch. In the documentation it says that my community name is probably wrong.
How do I see a community name of the switch? How do I set/change the community name?

Thanks!!

 

[NetEng631]

You have to configure the switch for SNMP. Go to CCO (the cisco web site) and search on how to enable SNMP. You basically need to set up a community string, its easy.

 

[frl]

Thanks,

I have found it on the Cisco pages.