I know this is off topic, but this is such a sharp group, and does involve a SuSE box: I went to install a SuSE box onto an existing network. The network has been having horrible lag times, but only periodically. In looking it all over I found a Windows 2000 Pro server they had on the network with 2 NIC cards plugged into the same hub. The NICs get their IP from a router with DHCP, so they each have their own IP but on the same class C. This can't be good. At best I can not see where anything is gained, at worst it may be responsible for the network problems. Before I tell the guy who set it up he is crazy, did I miss something? Greg Engel
Greg Engel wrote:
In looking it all over I found a Windows 2000 Pro server they had on the network with 2 NIC cards plugged into the same hub.
Are you sure it's a hub, and not a switch? Because if it's a hub, then, yes, it doesn't make any sense. If it's a switch, then, some switches can do bandwidth aggregation, if you use more than one network card on a computer. I don't know if Windows can do it (Linux can). You need to have a switch that knows it and an OS that knows it. -- Linux/Unix Systems Engineer http://www.genesys.ro Phone +40723-267961
On Tue, 2003-02-18 at 08:28, Silviu Marin-Caea wrote:
Greg Engel wrote:
In looking it all over I found a Windows 2000 Pro server they had on the network with 2 NIC cards plugged into the same hub.
Are you sure it's a hub, and not a switch?
It is a hub for sure. This is a simple local network with about 10 stations. All access is done using workgroup shared folders, so I can not think that it would have load balancing available. Greg Engel
At 08:45 AM 2/18/2003 -0500, you wrote:
On Tue, 2003-02-18 at 08:28, Silviu Marin-Caea wrote:
Greg Engel wrote:
In looking it all over I found a Windows 2000 Pro server they had on the network with 2 NIC cards plugged into the same hub.
Are you sure it's a hub, and not a switch?
It is a hub for sure. This is a simple local network with about 10 stations. All access is done using workgroup shared folders, so I can not think that it would have load balancing available.
The first thing I would do is replace the hub with a 12 port switch and see how your bandwidth improves. Switches have come down enough in price so that everyone can afford them. A hub operates at Layer 1 of the OSI, and is by definition shared bandwidth, a switch operates at Layer 2 and provides each port with dedicated bandwidth. Enable SNMP on the servers, and see who the bandwidth hog is, then deal with it.
Greg Engel
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The first thing I would do is replace the hub with a 12 port switch and see how your bandwidth improves. Switches have come down enough in price so that everyone can afford them. A hub operates at Layer 1 of the OSI, and is by definition shared bandwidth, a switch operates at Layer 2 and provides each port with dedicated bandwidth.
Enable SNMP on the servers, and see who the bandwidth hog is, then deal with it.
Are the linksys an netgear switches that good. They are about the same cost of hubs by the same company or very close. I have 2 16 port netgear switches an one 8 port netgear switch, then one very old linksys from the very beginning of the network setup left in the picture. Just wondering if they are that good or should I go to better brands in the future when I need to replace them. I started out with the one linksys switch an serval hugs in the beginning. Have only one hub left in the building an its in the back plant offices where production staff offices are.
on the SNMP suggestion you gave the other guy, how do use that. I have snmp installed on my servers here. One is production server an then my test server.
thanks for info. jack
Are the linksys an netgear switches that good. They are about the same cost of hubs by the same company or very close.
I've never used linksys or netgear, we used to used 3Com and Allied Telesyn switches, but those have been replaced by Cisco 3550's and 2950's (backplane is much larger).
I have 2 16 port netgear switches an one 8 port netgear switch, then one very old linksys from the very beginning of the network setup left in the picture. Just wondering if they are that good or should I go to better brands in the future when I need to replace them.
Well, if the switches are working fine, no need to replace them, or replace them one at a time with higher end switches (cisco 2950's cost about 700/800) and do a fine job, and provide the ability to VLAN (traffic isolation), etc. Cisco 3550's are good for your backbone at your office. Also, make sure that you don't have bandwidth/duplex mismatches on your network, this can result in collisions on your network (and you don't even know it). Either set the switch to autosense (if this can be done), or set it to 100mbit/full duplex (on both sides).
on the SNMP suggestion you gave the other guy, how do use that. I have snmp installed on my servers here. One is production server an then my test server.
I use MRTG under linux to pull stats from servers, routers, switches, etc. It will poll anything that is available under SNMP v1/v2 (produces NICE graphs) to see what is going on. If you have a web server, something like WEBALIZER under unix/linux will graph web server statistics for you (does a great job, and is easy to set up). -Bill
On Tue, 2003-02-18 at 11:36, Bill Parker wrote:
Enable SNMP on the servers, and see who the bandwidth hog is, then deal with it.
Along that line, would SNMP clue me in on if there was a bad NIC in the network? I have never actually worked with SNMP. Is it simple to implement under Linux? Greg Engel
Greg,
Enable SNMP on the servers, and see who the bandwidth hog is, then deal with it.
Or install ntop and use that (on the CDs (I think)).
Along that line, would SNMP clue me in on if there was a bad NIC in the network?
SNMP is unlikely to help detect bad remote NICs. If you use intelligent switches or a router they'd probably be able to tell you more.
I have never actually worked with SNMP. Is it simple to implement under Linux?
Yup, have a look at ucdsnmp - it's on the CDs but I think the latest version gets rid of some security issues. Damian -- Damian O'Hara using: SuSE Linux 8.0 12:49pm up 83 days, 3:58, 11 users, load average: 0.08, 0.02, 0.01
* Damian Ohara (daohara1@email.mot.com) [030220 05:12]:
Yup, have a look at ucdsnmp - it's on the CDs but I think the latest version gets rid of some security issues.
No, the latest version (the net-snmp series) doesn't include the audit that our security team did to ucdsnmp last year yet. That's why I haven't updated the package to the net-snmp tree. If you are going to seriously use (i.e., not just snmp v1) snmp and are willing to help test contact me off the list and I'll send you 4.2.6 built for whatever SuSE version you need. It has fixes for lots of non-security related bugs as well. -- -ckm
participants (6)
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Bill Parker -
Christopher Mahmood -
Damian Ohara -
Greg Engel -
Jack Malone -
Silviu Marin-Caea