Does a Firewall slowdown downloading/uploading speed?

Is it true that using a software Firewall will slowdown the download/upload speed?

:spit: :chuck:

It depends on what is being analyzed by the FW, but in general, yes. The degree is based on a number of things like hardware, rules, etc.

Hi,

The horse13 is correct (as usual :p )

It depends on the software..............for example McAfee7 and Zone Alarm do not get on together. realistically, the difference should be milliseconds, but if you have a software incompatibility and the attendant memory leaks, it could be big time.

Sorry mate, need more info. on the hardware and software :)

Good week-end

Johnno

if your worried about downloads taking longer....dont. On your home computer and most corporate networks you will not see any difference. What will really slow your download speed is a worm on your computer scanning for more victims or eating the files that have taken you so long to download. Anyone that tells you they wont use a firewall because it slows down file transfer is a fool.

Quote:

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Anyone that tells you they wont use a firewall because it slows down file transfer is a fool.

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Yes Tedob1, certainly this is true. A person will not notice the difference. I was referring to the extreme technical nature of the question, which the answer, technically, is yes. :)

im not sure this is always the case though i install tiny personal on my comp and it seemed to make my down/upload speed quicker.....

Hmmmm, that would suggest to me that other things are running that were eating up your bandwidth before you installed the personal firewall. Do the logs show anything? Perhaps you have some spyware on your box.

thehorse13 please dont think my reply was aimed at you...or anyone else for that matter. im not desputing the facts. i was quessing at his reason and could be totally off the wall but that needed to be said in case im right.

Yes, but I would say, unless your using a very intensive firewall-IDS hybrid, it's not going to be very noticable.

- Noia

Similar to other posters, but

Quick answer : No

Slow answer
A normal rule-filtering firewall (the kind that post people use) will delay packets being received / transmitted by a very small amount. Not much though. This won't affect the throughput (i.e. download speed), but it will increase the latency very marginally. In practice this effect won't be able to be measured, because the latency increase will be much less than the general latency in the internet in general.

Content-scanning firewalls will significantly slow down downloads, because they have to check everything against some lists and/or rules of things not to download. Different ones work in different ways, hence will probably have different performance characteristics.

If you're worried, try a few different vendors' ones out and measure the speed before implementing such a solution on your network

Slarty

Slarty's comments are interesting. I have seen e-mail servers almost grind to a halt, because of emergency content filtering to block particular virus attacks.

Some organisations get third parties to handle their external e-mail. This includes content filtering and AV scanning. Frequently they use up to four different AVs that are updated hourly. One of these will be a "heuristics" based scanner that looks for "new" viruses based on behavioural analysis.

This slows down your e-mail, but you so not "see" it, as it is happening remotely, and your local server is running "normally" particularly for internal e-mails. You could probably create this yourself if you separated internal and external connectivity.


Cheers

It does slow down your up/down speed but not to a degree that is noticable. It would be also difficult to measure the amount of the slowdown ad there are a lot of other factors tha might contribute to the slowdown. remote server, ISP bandwidth..... It slows down cos the system will have to check the incoming/outgoing traffic with the set of of rules to determine what to allow in and what not to.

Even after saynig all this, i have to add that you will not notice the difference in speed when up/downloading and also there might be other things affecting the speed.

Anyway, its better to have a firewall when you are connected. especially if its been confgiured right

In my experience:

I was running ZA and had everything set up perfectly the way I wanted it. When I got online to play Unreal Tournament 2003 my ping which was usually around 90-130 was up around 330-380 and it sucked big time. Thinking it was a ZA problem I uninstalled it and installed Tiny Personal Firewall with the same results. I assume this is because you are playing with up to 15 (16 counting yourself) players that the firewall is analyzing the data you are getting from them which is a hell of a lot in a big game. After I discovered that this was a problem (for me) I got a router and just locked the bastard down and uninstalled my software firewall. My ping went back to normal but I'm still not that good online in UT2K3 (lol). Like I said this is just my experience.

all you have to do is tell your firewall to let the game thru and you will go back to the normal ping.

Normally a software firewall will utilise much more resources ie CPU, and memory than a hardware firewall. A hardware firewall is a dedicated hardware to do filtering, else on a software firewall, you are running a software on top of the PC. How the CPU,memory resources are allocated are dependant on the OS of the PC.

A general rule of every firewall is this;
1) The more rules you have, the slower your firewall will be.
2) Hardware firewall is always faster than software firewall, but it is more expensive.

I think the best way to put it is:

If you have a well to over-powered system anyway - you'll never notice the differance...

If you have an average built or couple year old sytem - you'll notice a little bit of a differance, but not much...

If you have a system that is outdated or so low on resources its already slow - you'll likely notice a big differance

(And then obviously many varying degrees of severities in between each)

As they tend to effect CPU and Memory more then actual download/upload speeds, but if your CPU is already being overworked, or your systems already low on resources - well then the added load is going to be quite noticable... So obviously, the more overpowered your CPU and the lighter your resource load, the less your going to notice it...

and not to knock what ericc said - but

This is in regards to software firewalls which other then some of the most basic ones, do something differant then hardware firewalls do - which is why its always a good suggestion to run BOTH...

RRP