Constant internet connection lost.

Posted on 2006-05-31
Last Modified: 2010-04-08
I have constant internet connection lost.  Could the problem be collisions and deferred as can be seen below?  If so?  How can i correct this.  By the way, I have set

"interface ethernet0 10baset" for 10MBits half duplex and the Adtran 600R(to ISP) is also set at 10baset.

interface ethernet0 "outside" is up, line protocol is up
  Hardware is i82559 ethernet, address is xxxxxxxxxxxxxx
  IP address, subnet mask
  MTU 1500 bytes, BW 10000 Kbit half duplex
        28755 packets input, 17828201 bytes, 0 no buffer
        Received 17 broadcasts, 0 runts, 0 giants
        0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
        28242 packets output, 15903826 bytes, 0 underruns
        0 output errors, 275 collisions, 0 interface resets
        0 babbles, 0 late collisions, 282 deferred
        0 lost carrier, 0 no carrier
        input queue (curr/max blocks): hardware (128/128) software (0/4)
        output queue (curr/max blocks): hardware (0/27) software (0/1)
Question by:liep
    LVL 9

    Expert Comment

    Are you saying you don't get a connection, or it connects then drops out?

    Collisions is high so I would suggest you check the duplex rating on both ends. Are you sure the Adtran is half duplex? If it is auto sense then it would be worth setting the switch (you don't say what it is but looks Cisco IOS) to be full duplex or auto negotiate.

    Can you provide a little more information on the switch type and the settings at teh other end?

    LVL 79

    Expert Comment

    Whenever you have half-duplex connections you will always see some collisions. Your ratio of collisions to total packets is very low and within the acceptible range and should not be causing your situation. Do you see any alarm amber/red lights on the Adtran 600R? I would concentrate on looking at the T1 connections and cabling between the 600R and the wall jack and the SmartJack.

    Author Comment

    Let me rephrase,  it's periodic connection lost.  It has internet connection then drops for about 30 seconds and then there's connection again.  

    > Are you sure the Adtran is half duplex?
    I called up the ISP and they were setting it to 10Mbits Half duplex.
    When I put my outside interface to auto, it gets a couple of carrier lost while putting the outside interface in 10baset will not.

    > Can you provide a little more information on the switch type and the settings at teh other end?
    It's an Adtran Total Access 600R router.

    > Do you see any alarm amber/red lights on the Adtran 600R?
    No, It's green.

    > I would concentrate on looking at the T1 connections and cabling between the 600R and the wall jack and the SmartJack.
    I call our ISP.  They say their side has been showing consistent connection for the last few months with no drops.  They're saying it's our side that has the problem.

    Can it be my firewall not being able to handle heavy loads?  When my connection drop, the firewall seems to die too.  Any telnet connection to the firewall terminated during the drop.  Does this have anything to do with the PIX 501 firewall and its licenses?  I did a "sh xlate" and this is what I currently have.

    pixfirewall1# show xlate
    52 in use, 317 most used
    PAT Global xx.xx.xx.xx(9198) Local
    PAT Global xx.xx.xx.xx(9166) Local
    PAT Global xx.xx.xx.xx(9150) Local
    PAT Global xx.xx.xx.xx(9070) Local
    PAT Global xx.xx.xx.xx(9038) Local
    PAT Global xx.xx.xx.xx(9199) Local
    PAT Global xx.xx.xx.xx(9039) Local
    PAT Global xx.xx.xx.xx(8607) Local
    PAT Global xx.xx.xx.xx(9196) Local
    PAT Global xx.xx.xx.xx(9164) Local
    PAT Global xx.xx.xx.xx(9148) Local
    PAT Global xx.xx.xx.xx(205) Local ICMP id 512
    PAT Global xx.xx.xx.xx(9197) Local
    PAT Global xx.xx.xx.xx(9165) Local
    Global xx.xx.xx.XXX Local Fed-VPN
    PAT Global xx.xx.xx.xx(5866) Local
    PAT Global xx.xx.xx.xx(8602) Local
    PAT Global xx.xx.xx.xx(2619) Local
    PAT Global xx.xx.xx.xx(9176) Local
    PAT Global xx.xx.xx.xx(9128) Local
    PAT Global xx.xx.xx.xx(9048) Local
    PAT Global xx.xx.xx.xx(8440) Local
    PAT Global xx.xx.xx.xx(25) Local
    PAT Global xx.xx.xx.xx(9145) Local
    PAT Global xx.xx.xx.xx(9065) Local
    PAT Global xx.xx.xx.xx(8601) Local
    PAT Global xx.xx.xx.xx(9206) Local
    PAT Global xx.xx.xx.xx(8630) Local
    PAT Global xx.xx.xx.xx(8598) Local
    PAT Global xx.xx.xx.xx(9207) Local
    PAT Global xx.xx.xx.xx(9127) Local
    PAT Global xx.xx.xx.xx(9111) Local
    PAT Global xx.xx.xx.xx(9047) Local
    PAT Global xx.xx.xx.xx(8423) Local
    PAT Global xx.xx.xx.xx(9204) Local
    PAT Global xx.xx.xx.xx(9156) Local
    PAT Global xx.xx.xx.xx(9124) Local
    PAT Global xx.xx.xx.xx(9044) Local
    PAT Global xx.xx.xx.xx(8628) Local
    PAT Global xx.xx.xx.xx(9205) Local
    PAT Global xx.xx.xx.xx(9173) Local
    PAT Global xx.xx.xx.xx(9157) Local
    PAT Global xx.xx.xx.xx(9125) Local
    PAT Global xx.xx.xx.xx(8629) Local
    PAT Global xx.xx.xx.xx(9202) Local
    PAT Global xx.xx.xx.xx(8946) Local
    PAT Global xx.xx.xx.xx(8594) Local
    PAT Global xx.xx.xx.xx(9203) Local
    PAT Global xx.xx.xx.xx(9107) Local
    PAT Global xx.xx.xx.xx(9043) Local
    PAT Global xx.xx.xx.xx(5248) Local
    PAT Global xx.xx.xx.xx(9232) Local
    PAT Global xx.xx.xx.xx(9216) Local
    PAT Global xx.xx.xx.xx(9200) Local
    PAT Global xx.xx.xx.xx(9040) Local
    PAT Global xx.xx.xx.xx(8528) Local
    PAT Global xx.xx.xx.xx(9233) Local
    PAT Global xx.xx.xx.xx(9217) Local
    PAT Global xx.xx.xx.xx(9201) Local
    PAT Global xx.xx.xx.xx(9169) Local
    PAT Global xx.xx.xx.xx(9137) Local
    PAT Global xx.xx.xx.xx(8609) Local

    Is this normal?
    LVL 79

    Accepted Solution

    Perfectly normal pattern of xlates
    If you only have 10 user license, then yes, you may be hitting the license issue, but I would expect it to only affect certain users at a time, not all at once.

    >Can it be my firewall not being able to handle heavy loads?
    You only have a baby 501. It was never designed for heavy loads. It was designed purely for 10 user or less small office with normal web browsing activity and nothing more.

    Author Comment

    That might be it.

    We have 4 offices, and approximately 65 users.  I have been experiencing this problem after the convergence of the other three offices to ours.  Previously, the other 3 offices have their own internet and their own firewall, but I was told to incorporate everything into one.  Meaning all the other offices will access the internet through our main office's PIX 501 firewall and router.

    Do you have any recomendation for a firewall?

    LVL 79

    Expert Comment

    I really like the new Cisco ASA5500 series. I would highly recommend an ASA5510 appliance for you. You can get web content filter module if you want. The whole PIX line will be going away soon,  replaced by the ASA products. The ASA combines the best of PIXv7, VPN3000 and IDS sensor in a modular chassis.

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