Netcomm NB5

[fcug]

I need some advice on Port Forwarding a Netcomm NB5 ADSL2+ Modem/Router in Australia.
The portforward.com website shows Azureus and other file transfer programs as
"source IP address and source netmask as 0.0.0.0"
The Netcomm NB5 defaults the " destination netmask as 255.255.255.255 " and
can't be changed (see attachment), are these addresses correct

[Variable]

This looks correct. What you are saying is ..allow any IP address to connect to 192.168.1.136 only on TCP port 49152.

A destination mask of 255.255.255.255 means only the IP specified. You cannot port forward traffic to more than one internal IP.

[fcug]

Thanks Variable, I was unsure about destination mask!

[Daniel-Man]

hi guys, wouldn't this mean that any hacker can go straight through your computer if they use a port sniffer and find port 49152 open???

[Variable]

No, it doesn't. You’re giving a hacker too much credit. But it is certainly a risk. Any application running on your PC opens ports that it listens on. I don't know how old you are but, if you can remember a movie showing a telephone switchboard, where an Operator sat in front of a board with holes in it and moved wires around to make connections for phone calls. This is what ports are like. Applications use different ports, some are defined and some are ephemeral. An example of ports are http port 80 and DNS which is port 53. Every application has code written for it and the code does certain things. This is where vulnerabilities come in. Imagine a application with poorly written code that could allow a clever person to exploit the code by crafting a special set of instructions; they then send those instructions over the listening port. Depending on the exploit you can get different results. For example, A chat application may not have the ability to do any harm to your machine even if there is poorly written code that is exploited. But programs that have a great deal of power on your machine, that are linked with many other applications and the OS, say for instance, Internet Explorer, poorly written code can cause some real problems. The issue is one of complexity and functionality. The more feature rich and user friendly an application is, the greater the likelihood that it is complex; creative minds can find segments of this code that can be exploited.

[Daniel-Man]

Is 192.168.1.136 the IP address of the computer on your network? In my case I'm guessing it's 192.168.1.100 as that's the one that's been assigned? For protocol is it just TCP that needs to be selected or TCP and UDP also?

[Daniel-Man]

Just applied the settings, OMG I'm finally getting some decent Azureus speed!!!! 50-100KB/s and most of them are green instead of yellow or red!!!! One of the d/ls even getting up to 140KB!!! I think the settings have finally been configured properly, at last!!!

I have noticed though my total download speed is between 250-300KB, (my connection can usually support about 700-800KB/s) but my Internet explorer browsing is taking longer for pictures and pages to download. Has anyone experienced this? and knows how to fix it?

I remember this happened last time I tried to configure my port forwarding too, which is why I turned it off last time.

[Variable]

So you are downloading a bunch of files with a p2p program and you wonder why Internet Explorer is slower loading pictures?

[Daniel-Man]

Yes that is correct! I don't understand why IE is going so slow!!