Performance issues



  • Hello all,

    I am just wondering what general troubleshooting techniques people are using for performance issues?

    I have a PIII 500 with 386MB of RAM.  I have four 3com cards divided into a LAN, WAN, DMZ, and Wireless networks.

    The WAN card is plugged into the cable modem.  Any traffic we measure from the DMZ or LAN or Wireless to the WAN is very slow.  We measure this by going to speedtest.net.  We are lucky if we get 1MB download.

    However, if we plug directly in the cable modem, we get the full 5MB download speed.

    I am leaning towards a NIC problem.  I believe that they are somewhat old.  I am willing to replace them.  But if there is something I can do to fix them first, I would prefer that.

    Also, in the error log I am getting the following messages:
    Apr 18 15:41:14 php: : Hotplug event detected for xl0 but ignoring since interface is not set for DHCP
    Apr 18 15:41:14 php: : Hotplug event detected for xl0 but ignoring since interface is not set for DHCP
    Apr 18 15:41:13 check_reload_status: rc.linkup starting
    Apr 18 15:41:13 kernel: xl0: link state changed to UP
    Apr 18 15:41:12 kernel: xl0: link state changed to DOWN

    I have also turned off PnP.

    Any ideas or suggestions?

    Thanks!

    Jeremy



  • May sound strange but try a longer ethernet cable.

    Many drivers have short cable bugs.



  • strange but I have to agree. we first started evaluating pfsense a couple months ago and saw very poor performance to/from 3com nic and any other nic. which was weird b/c we'd figured it should be more solid than e.g. realtek.

    not sure if we were using short cable in those tests. (I do have some vague recollection of the short cable error) anyway, in tests we switched to a $5 refurb intel 82559 and life was good.

    so far fxp is the best of course, but also experienced no problems with vr, rl, or sis.

    these are damned useful when you can find them in stock:
    http://www.geeks.com/details.asp?invtid=A-3905
    maybe it's a "router card" in microsoft-land, but basically it's an 8139 with integrated realtek 4-port switch chip. obviously you can't hope for amazing performance but it serves a purpose fairly well.



  • The most common performance issues are:

    • duplex mismatch

    You seeing errors or collisions on your Status-> Interfaces page? Does the duplex seem to be what it should be? (which will depend on what you're plugged into)

    • undersized hardware

    not the case here.

    • bad NIC or cable, or something else causing excessive interface errors

    You'll see if this may be an issue on Status -> Interfaces.



  • Well, all of the cables are 10 foot cables.  We have tried different ports on the cable modem.  We have tried different cables.

    I have also looked to see if there was any errors on the interfaces.  Actually that was the first thing that I did.  There were none.

    I believe that they are 3com 905cs, but not positive.

    I thought that it could be duplex/speed mismatches as well.  That is usually one of the first things I check when I see network performance issues.  However, the cable modem is owned by the cable company.  So, we dont' have any access to it.  It is set to auto.  So is the card.

    I was thinking of picking up some of these:  http://www.newegg.com/Product/Product.aspx?Item=N82E16833166004 .

    They use a realtek chip in them.



  • You have 3Com NIC's, getting anything with a Realtek chipset would be taking a major step back. Those are substantially slower than 3Com cards. If you're going to switch NIC's, switch to Intel. That's about the only way to move up.

    You sure you don't have a duplex mismatch? It sounds very much like you do. Not just concerned with WAN, but check all other interfaces as well. If everything's auto it should be fine.



  • I will check it again tomorrow.

    But I am sure that there were no errors on the Status:interfaces page.



  • I bet it's a duplex mismatch. Look for collisions. The 3Coms are probably at half, and the cable modem at full. I had a ton of trouble with poor performance from the 3Com 3c905c's in Windows 98 computers years ago. They really didn't like to go full duplex unless connected to a 3Com switch. Even when set to full duplex instead of auto, they would either not connect at all, or would run half duplex and really slow. Replacing them with cheapy 8139 Realteks actually fixed the problem for us back then. I would recommend Intel's though. I've been able to get some of the Realtek gigabit NICS to work really well with PF, but had nothing but trouble out of others. You also might try setting the media type to full and see if that helps in FreeBSD, but it didn't help us in Windows.



  • Ok,

    Here is what happened.  Well, my boss already had ordered the Rosewill cards.  So, we put them in today.  Same problem.

    So, the first thing I think of is duplex mismatch.  I open up the console on both the firewall and the two switches for the LAN and DMZ.  They are older Cisco 1900 switches.  No errors anywhere.  So, I get a cross over cable and plug into the actual cards from my PC.  Speeds are now acceptable.  So, I am really confused.  Use the wireless, which is a Linksys WAP.  Speeds are acceptable.  So, it is definitely something with the Cisco switches.

    So, I try plugging into ports other than the uplink ports.  The firewall renegotiates to 10 full from the 100 full.  Still the same problem.  So, I am thinking that something on the switches are screwed.  We are ready to go out and purchase some new, cheap, non mananged switches.  I have one last idea, reset the switches to factory default.

    That solves all the problems.  In fact, it solves problems that I did not know existed because apparently the lan was slow without the firewall in the mix.

    I did not do the initial config of the switches.  I am not sure what they were configured to be doing.  But, it was slowing down traffic all across the board.  Even from port 1 to port 2.  After the reset, everything is flying.

    Still never saw any errors.

    Thanks for everyone's help!!



  • Never heard of such an issue with a switch, though it's been a LONG time since I've even seen, much less worked with, a 1900. Those aren't great switches, you can pick up something like a HP 2400 or 2500 or Cisco 2924 for really cheap on ebay.



  • Yeah,

    I have been trying to convince him to just go get some cheap unmanaged gig switches.  But I think he likes the fact that he can manage the current ones.  Which is nice in an enterprise environment.  But, in ours, I don't think that it is necessary.

    I talked to a friend of mine about it.  He suggested that perhaps spanning tree was set up on the switches at one point was really confused.  Who knows.

    But, apparently it has been this way since before I got there six months ago.



  • Managed gig switches aren't even all that pricey anymore unless you need a bunch of ports. I have a managed gig switch at home, though it was purchased by a pfsense supporter. Netgear GSM712, it's a great switch, and you can pick one up off ebay for ~$150 shipped if not less for 12 gig ports. Roughly the same price as a 24 port HP or Cisco 10/100 switch. I've also had good luck with Dell PowerConnect switches and they're cheap on ebay as well.

    With replacements under $200 it's not even worth arguing over, pick up some modern switches and and dump the 1900's in the trash. Managed switches are ALWAYS good, not just in big environments. I won't even use an unmanaged switch at home.  ;D


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