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Posted

Hi All

 

I am hoping someone can help me setup our switches we have a procurve 9304 connected to servers then we have fibre links to each blocks switch which is a 2650 or 4108. What is the best way to setup the switches at the moment they are all setup as they were when they left hp except I have given them all static ip addresses. The mac address tables seem really messy some ports are reporting mutiple mac address on them and the ports that are the fibre links report almost every mac address in the school as being attached to them. Can I clear the mac address tables? Should the fibre link ports be reporting hundreds of mac addresses or not should they not just report the mac address of the switch they are connected to.

 

Any help would be great

 

Thanks

 

Carl

Posted
Is it good or bad the switches knowing all mac addresses? Can we clear mac address tables? so old entries are removed.
Posted (edited)

Are you actualy having any problems? As Andy has said all MACs should be listed, not just the ones connected direcly to the switch.

 

Is it good or bad the switches knowing all mac addresses? Can we clear mac address tables? so old entries are removed.

 

It's good, if the switches don't know the MACs they don't know which port to bung the data down.

 

Most switches the MAC table clears when you reboot the switch, but it'll fill back up very quickly.

Edited by K.C.Leblanc
Posted

Yes, switches are supposed to know where all the mac addresses on a LAN are. Clearing the arp tables would do nothing as they would simply rebuild over time.

 

The only reasons you would want to do something about this is if your large arp tables are exceeding the memory in your switch(es). This will result in poor performance and/or crashing switches. The other reason is if you are having excessive broadcast traffic caused by ARP who-has requests.

 

Both situations can be alleviated by carving up your physical lan into several VLANs. Usually based on physical location (i.e. one VLAN per building/floor/department) and using your central switch as your router.

Posted
we are having some problems with network. First thing in morning people log on and don't get shared drives and problems with wake on lan. We were worried if all switches knew all mac address the magic packet for wake on lan is getting sent to the wrong place and ageing before it gets to the right place. We are unsure if it network switch related or not but thought now is a good time to check the switch and network setup.
Posted
If i was to create Vlans for each building will it cause problems with rm cc3 we have had problems in the past with rstp upsetting RM
Posted
Rapid Spanning Tree Protocol has nothing to do with VLANs. I imagine the problem you had in that case is that you were setting RSTP on edge ports.
Posted

hi carlday

 

You do not want to clear the Mac address table as its used to forward frames to the right port! Mac address however should age out of CAM when not used.

As for your switch configuration you may want to configure VLAN (subnet your network) and some kind of anti loop feature such as STP

 

VLAN's are usually recommended to break up your broadcast domain and save bandwidth!

 

how large is your network (e.g how many nodes)?

Posted
we are having some problems with network. First thing in morning people log on and don't get shared drives and problems with wake on lan. We were worried if all switches knew all mac address the magic packet for wake on lan is getting sent to the wrong place and ageing before it gets to the right place. We are unsure if it network switch related or not but thought now is a good time to check the switch and network setup.

 

How many nodes have you got?

 

What bandwidth can the ports on the servers containing the shared drives use? ie. 100Mbit 1000Mbit etc...?

Posted

I would highly recommend connecting your servers at 1gbps as well as subnetting your network e.g VLANS

 

I believe its recommended to start subnetting when your reach around 100 nodes. I take it you have a flat network with no subnets?

Posted

Hi

 

We have a flat network no vlans. Does RM CC3 let you connect servers at 1gb also will rm build under a network with Vlans.

 

Carl

Posted
I would highly recommend connecting your servers at 1gbps as well as subnetting your network e.g VLANS

 

I believe its recommended to start subnetting when your reach around 100 nodes. I take it you have a flat network with no subnets?

 

I agree with this. 100Mbps is not really enough sometimes. We sometimes manage to hit 300Mbps on our file servers etc... for ~300 nodes.

 

And the background ARP traffic will be using a fair amount also. VLANs are your friend here.

Posted
Hi

 

We have a flat network no vlans. Does RM CC3 let you connect servers at 1gb also will rm build under a network with Vlans.

 

Carl

 

CC3 should have no interaction with the actual hardware of the server - this will be handled by windows itself. So yes, it will handle it.

 

On the CC3 issue, I'm not sure - there are a few mentions of it on the forums here, one person saying it required a few changes to hosts files but that's about it.

Posted

Carl

 

I'm going to be a dissenting voice on this one. I really can't see VLANs being the answer to your problems. We're running a procurve based network here and have a vlan over twice the size of your whole network with no problems and no excessive broadcast traffic.

 

IMHO your first task is to get your servers connected at gigabit speed.

 

If you're concerned about broadcast/arp traffic levels, install a sniffer (wireshark etc) on a pc and see what's on the wire. If there is really an excessive amount of broadcasts you need to track down where they're coming from and sort that out.

 

None if this is to say that vlans aren't useful - they just aren't the way to solve your immediate problem.

Posted
Carl

 

I'm going to be a dissenting voice on this one. I really can't see VLANs being the answer to your problems. We're running a procurve based network here and have a vlan over twice the size of your whole network with no problems and no excessive broadcast traffic.

 

IMHO your first task is to get your servers connected at gigabit speed.

 

If you're concerned about broadcast/arp traffic levels, install a sniffer (wireshark etc) on a pc and see what's on the wire. If there is really an excessive amount of broadcasts you need to track down where they're coming from and sort that out.

 

None if this is to say that vlans aren't useful - they just aren't the way to solve your immediate problem.

 

You will still be wasting a lot of bandwidth on broadcast traffic slowing your network!

Posted (edited)
You will still be wasting a lot of bandwidth on broadcast traffic slowing your network!

 

That depend on your definition of 'a lot' ;) It's reasonably busy here at the moment and i'm seeing 0.1% broadcast packets on the links to our servers. Why would you expect to see anything more than a few arp packets and dhcp requests?

Edited by keithu
typo

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