Internet speed reduce if behind firewall

Posted on 2013-01-05
Last Modified: 2013-01-24
Today one of my client is upgrading their internet plan to more high speed and the download speed is 20 MB ,but we do a test in LAN PC ,the speed we can get is 13MB only but i do a test infront of firewall ,that is no Problem and we can get 20MB ,may i know what are the possible cause for this issue ?
Question by:warriorsTeah
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 25

Expert Comment

by:Tony Giangreco
ID: 38748018
All hardware firewalls have a max limit on throughput speed. 13 meg sonds very low, but it may be your max speed. You can look up the specs of your firewall to verify the throughut max. Your internet connection is probably  7 to 20 down and .768 to 6 up.

You didn't specify what firewall you have.

Most firewalls have a max speed between 100 & 400 Megs. Enterprise firewalls will go higher.

Author Comment

ID: 38748045
Safe@office 500
LVL 10

Accepted Solution

Nancy McCullough earned 500 total points
ID: 38748055
Being that your speed can only be as fast as your slowest connection, and it is quickest in front of the firewall, then yes, it is your firewall - or any connectors to the firewall. Start with the cheapest solutions: check to make sure that your firewall's software is up to date, your cords and cables are secure, you are hard wired and not wireless (wireless has latency). If all is good with those items, start to look at the more expensive things to fix: hardware. Is your firewall max down speed 13 or closer to 20? If the max is slower than you want: replace the firewall.
Flexible connectivity for any environment

The KE6900 series can extend and deploy computers with high definition displays across multiple stations in a variety of applications that suit any environment. Expand computer use to stations across multiple rooms with dynamic access.

LVL 26

Expert Comment

ID: 38749019
Your firewall's specifications say that it can handle traffic far faster than you're getting.

Perhaps you have aggressively set the protection it offers?  Have you tried turning SmartDefense to Minimal, turning of VStream, and disabling the subscription services, to see if any of those are what's causing your slowdown?
LVL 37

Expert Comment

ID: 38749026
going on these specifications, the firewall can handle the throughput, but I would suggest checking what level of packet inspection you are performing on the firewall as this can impact throughput

Author Comment

ID: 38749407
Please guide me how to check what you mention about

Author Comment

ID: 38749412
Packet shaping can be a cause for that or rules in firewall ? What is packet shaping ?
LVL 26

Expert Comment

ID: 38749420
Review the manual for the firewall.  You can find it here:

Expert Comment

by:Sandeep Gupta
ID: 38749997
You need to check if any policing or bandwith is set on the firewall inteface.

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
SonicWall Max Connection Setting 7 44
Unmanaged Switches for Optimized Network Speeds 7 60
OSPF - Convergence & Downtime 9 78
port redirection on cisco asa 5520 5 30
This article offers some helpful and general tips for safe browsing and online shopping. It offers simple and manageable procedures that help to ensure the safety of one's personal information and the security of any devices.
I recently attended Cisco Live! in Las Vegas, a conference that boasted over 28,000 techies in attendance, and a week of hands-on learning hosted by a solid partner with which Concerto goes to market.  Every year, Cisco displays cutting-edge technol…
After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question