7 Replies Latest reply on May 21, 2010 4:13 PM by kuludown

    SG560U extremely slow internet

      just installed an sg560u... this is a new install with NO prior config to upgrade from. out of the box, it had firmware 4.0.0, which we immediately upgraded to 4.0.6. got the unit configured and installed last wendesday. this unit replaced an old router on which the internet speeds were normal to fast.

      ever since, the internet has been really slow. usually the router looks fine in the status until it has been running for a few min, then it pegs at 100% cpu usage [30%user; 68% kernel]. after it has been running for an hour or so, the router becomes so slow that there is no internet traffic.

      after rebooting the router, the whole scenario starts over!

      this office has a dedicated T1. an internet speed test from a computer on the network shows about 0.68 Mb/s down and 0.54 Mb/s up.


      any ideas?

        • 1. Re: SG560U extremely slow internet

          You probably need to contact technical support with a latest tech support report. Initially it seems to be a configuration issue.


          Do you have QOS autoshaper enabled?

          For test, try disabling the VPN services (pptp/ipsec/l2tp).


          when the unit pegs up to 100% or about to reach 100, try to login via telnet/ssh and run the following commands:


          ps -a   -- to show all running processes


          top   -- a utility like task manager in windows


          cpu -r   -- to get live cpu usage information



          Try to find out which process is consuming memory/cpu too much.


          Sending the output of these commands (with screenshots) will help the support to find out the root cause of your problem.

          • 2. Re: SG560U extremely slow internet

            no autoshaper, content filtering, or rules are enabled. l2tp was not enabled, pptp and ipsec were. i disabled both and found no change in performance.

            called support and they couldn't figure it out. they are supposedly escalating the call but i haven't heard anything in over a day.



            Message was edited by: kuludown on 4/7/10 4:40:19 PM CDT



            on 4/7/10 4:40:34 PM CDT
            • 3. Re: SG560U extremely slow internet

              Are you equipped to do a simultaneous packet capture both ahead of and behind the firewall (but not capturing using the firewall itself) during the period you experience the problem?


              An examination and comparison of the two captures may point to what the nature of the slowness is (packet loss/retransmission, DNS, arp, filtering, etc).


              A SHORT (a few seconds) on the SG560U itself might be useful, but if the problem is a switch-loop/broadcast storm on one of the two sides of firewall, the capture can very quickly become too large and cause you to lose web access to the firewall (requiring a reboot).


              Captures made with a seperate PC listening on both sides using Wireshark or tcpdump would be most effective.

              • 4. Re: SG560U extremely slow internet

                Can you Personal Message me the support ticket number ?

                • 5. Re: SG560U extremely slow internet

                  I am having the same issue. Is there a resolution to this. I am running firmware 4.07. CPU sits at 100 percent 35%usr and 65%kernel. I cannot seem to run the "Top" or "CPU" commands from SSH or Telnet to get the CPU info


                  # ps
                    PID USER       VSZ STAT COMMAND
                      1 root       428 R    /bin/init
                      2 root         0 SW<  [kthreadd]
                      3 root         0 SWN  [ksoftirqd/0]
                      4 root         0 SW<  [events/0]
                      5 root         0 SW<  [khelper]
                     37 root         0 SW<  [kblockd/0]
                     47 root         0 SW<  [khubd]
                     66 root         0 SW   [pdflush]
                     67 root         0 SW   [pdflush]
                     68 root         0 SW<  [kswapd0]
                    116 root         0 SW<  [aio/0]
                    172 root         0 SW<  [mtdblockd]
                    219 root         0 SW<  [scsi_eh_0]
                    220 root         0 SW<  [usb-storage]
                    242 root         0 SW<  [kjournald]
                    246 root         0 SW<  [loop0]
                    255 root       540 S    watchdog /dev/watchdog
                    274 root       552 S <  /sbin/udevd --daemon
                    403 root         0 SW<  [ixp400_eth]
                    405 root         0 SW<  [ixp400_eth]
                    529 root         0 SW   [crypto]
                    530 root         0 SW   [crypto_ret]
                    693 root      1664 S    statsd daemon
                    871 root       368 S    /bin/inetd
                    872 root       472 S    /bin/flatfsd
                    873 root       552 S    /sbin/syslogd -n
                    874 root       544 S    /sbin/klogd -n
                    875 root       368 S    /bin/cron
                    876 root       768 S    /bin/ifmond
                    877 root      1708 S    /bin/acld
                    879 root         0 SW   [ixp400 eth1]
                    882 nobody     472 S    /bin/dnsmasq -k -T 0 -b -l /etc/config/dhcpd.leases -
                    885 root       720 S    /bin/ntpd -g -n -Q -U 60
                    886 root       952 S    /bin/nflogd -p -d -c
                    923 root         0 SW   [ixp400 eth0]
                    943 root       836 S    /bin/pppd file /etc/config/pppoe.eth1
                  6309 root      5780 S    sshd: root@pts/0
                  8008 root       556 S    -sh
                  26283 nobody       0 Z    [sh]
                  26945 root       684 S    /bin/httpd /home/httpd
                  26948 root       680 S    /bin/httpd /home/httpd
                  27034 root       680 S    /bin/httpd /home/httpd
                  28020 root         0   []
                  28021 root         0   []
                  28022 root       544 R    ps
                  28023 root         0   []
                  28024 root         0   []
                  # cpu
                  -sh: cpu: not found
                  # top
                  -sh: top: not found

                  • 6. Re: SG560U extremely slow internet

                    resolved ?

                    • 7. Re: SG560U extremely slow internet

                      yes, we got it resolved...this is the workaround:


                      under network setup\lan settings we had an entry for the router's internal IP address listed as the dns and possibly as the gateway. after removing these entries, the cpu went back to normal and internet speeds work like they should.