Weird Internet Connectivities

HI All expert..  I have weird Internet Issue last few days (about two weeks) that I am struggle to find a issue.  We have Sonicwall 3600 and HP switches and Verizon provide 150/150. When Intenet works the speed came up 146/167 but when it is not working correctly 3.5/26. It seems that every morning it happens. i thought it was Sonicwall issue, but Sonicwall engineer can't find anything wrong. However, if I restart the router (Sonicwall), everything comes back to normal. It seems that I have to restart every morning. But this morning, i didn't restart but unplug uplink (Verizon) from Sonicwall and  plug back in and comes back to where it should be.  Any suggestion?
Who is Participating?
MoonLiveConnect With a Mentor Author Commented:
i just want let everyone know what is going on if you are interest. Here is what i found out so far: shows possible issue, but it doesn't solve my issue. Sonicwall techsupport ask me to move WAN interface to other interface. I didn't have to reset the Internet connection to gain speed this morning, so i guess it works for now. It is possible that my default X1 interface has a problem. i will look next few more days and see if the speed retain what it supposed.  Thanks everyone.
DarinTCHSenior CyberSecurity EngineerCommented:
for a test plug a laptop directly into you connection before it runs thru any network device and test speeds

also the logs on both devices should be able to provide you some details

and verizon should be able to test there equipment up to you

they may have a need for a firmware update or they may have performed one recently
I am not very familiar with Sonicwall, but general approach is:

Check speed and duplex, firewall logs and errors on WAN interface and on interface facing HP switches.

Speed should be, most likely (since it is 150Mb), 1Gb and duplex, I guess full (maybe you should configure it manually, not auto (on both sides)).

Also check CPU usage on devices.
Worried about phishing attacks?

90% of attacks start with a phish. It’s critical that IT admins and MSSPs have the right security in place to protect their end users from these phishing attacks. Check out our latest feature brief for tips and tricks to keep your employees off a hackers line!

MoonLiveAuthor Commented:
PredragJovic, it is good point about the speed, but the setup was working for a while. The switches and router has 1G connection. However, have following setup:

Bandwidth Management
 Enable Interface Egress Bandwidth Limitation
 Maximum Interface Egress Bandwidth (kbps): 153600.000000
  Enable Interface Ingress Bandwidth Limitation
Maximum Interface Ingress Bandwidth (kbps): 153600.000000

i wonder if this is causing anything..
Bandwidth limitation is OK. If you don't set it speed limit (configure bandwidth on Cisco devices) and use QoS - QoS most likely will not function properly.

Speed problem occasionally can be caused by network loops (high CPU usage on devices), wrong duplex settings cause many times activated CSMA/CD and it aditionally can cause TCP session to have small TCP windows size (to many errors) etc.

Also problem can be electronic components of device if ti is overheating or something similar. Heating is weakening many electronic components, but typically capacitors are the first with the problem in that case, and that can cause all kind of symptoms. I had some switch with bad capacitors and it was really nightmare until I figure out root cause of the problem and just replace capacitors.
MoonLiveAuthor Commented:
no other solution provided.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.