Can static pap ip affect router???

[joyce]

New problems....after setting up dmz host in router, the dmz kept changing every few days. Last night Viatalk set me up with a static ip for the adapter. This morning, my calls started dropping in the middle, just like cell phone calls. I noticed at the same time the call dropped, I could not connect to the internet, however my computer showed no icon for the lan or wan being down. My cable company swears no problems...

Any ideas anyone????

[jnuzzi]

If your computer is connected to the router and the router is powered on you will not see any connection errors on your computer even if the router's connection to the internet is down. If you cannot open up Google or Yahoo at the same time that your call drops then you almost certainly have a connection issue.

What are the specifics of your setup (router model, cable modem model, ISP, etc.)?

[DracoFelis]

New problems....after setting up dmz host in router, the dmz kept changing every few days. Last night Viatalk set me up with a static ip for the adapter. This morning, my calls started dropping in the middle, just like cell phone calls. I noticed at the same time the call dropped, I could not connect to the internet, however my computer showed no icon for the lan or wan being down.
What's the DHCP range of your router? i.e. Did you make sure that the IP address that was set in your VT adapter, wasn't an IP address that your router would later try giving to your computer?

If not, that could explain your problem. Because if you didn't do this, than your router would think it was free to assign to some other device (such as your computer) the IP address you put in your VT adapter. And when two (or more) network devices think they are the same IP address (on the same LAN segment), than your network will not be happy in the least...

In general having two devices (such as your computer and your VT adapter) assigned the same IP address, is going to cause you all kinds of networking problems. So while assigning a static IP can be good (from a stability standpoint), you have to be sure that the static IP you pick follows all of these properties:

1) The IP address you pick has to be one that your LAN can use. Since many home routers have a built in netmask of 255.255.255.0, that would mean that the 1st three numbers of the IP address picked, have to match what your LAN uses.

2) The IP address you pick must not be one that any other device (including the router itself) already has assigned to it on your LAN.

3) The IP address you pick shouldn't be the "broadcast" address on your LAN (with most routers/LANs, this means don't make the last digit of the IP address 255).

4) And finally the one that is easiest to forget about: You want to make sure any DHCP server on your LAN (with most home LANs their DHCP server is also their router) is told to never assign that IP address you picked. If you don't do this, than at some point in the future your DHCP server might assign that IP address to some other internet device (for example, your PC), because the DHCP server thinks that address is "unused" (because the DHCP server itself didn't assign it). And if/when that happens, two devices on the same network will both think they are the same IP address (which is "a bad thing" from a networking standpoint).

[connervt]

What draco said at the end of his post is why I don't give devices that attach to my network static addresses. Rather, I allow my router control, by "reserving" a different static address for each device's MAC.

When one of my devices comes on to the network, the router always gives it the same address, the DHCP lease never expires, and any port forwarding and/or QoS rules are always applied correctly.

If a temporary, new device is added (like a friend's laptop), it can then be assigned an address dynamically that will not interfere with my router's configuration.

If I take one of my devices (laptop, WiFi phone, ATA) to another network, it is already set to get an address dynamically, and I don't have to change/change back anything.

[jnuzzi]

I will second connervt's suggestion. This is exactly what I do on my network.

[joyce]

I think you guys are probably above my head, BUT:

I am running a wired Linksys BEFSR41 version 2.1. I have given my computer a static address of 192.168.1.2. I have assigned dmz host of 192.168.1.100. This was assigned by VT. They then made this a static address so I would not have to go in and keep changing the dmz host.

[connervt]

It's not that bad. A little basics:

Most home routers are used as a DHCP server, which function is to automatically assign IP addresses to all devices on the network which your router is responsible for (the router's "sub-net"). It makes sure that all addresses are unique (no two devices have the same address). Things get confused when two devices share the same address.

A DHCP server does a few other things, but these are not important to this discussion at the moment.

Now, there are several strategies for the network administrator (in this case, you at home) to handle IP addressing on your network:

-- Let the DHCP server (your router) and your devices (ATA, computers, etc) do it all automatically. This is what the majority of home users do.

-- Set a static (fixed) IP address on the desired device itself. This would be telling your PAP2T that it's address is 162.198.10.15, and it can't be anything else. This works fine most of the time, if there are rarely changes to your network.

-- Reserve IP address in the DHCP server (your router) for your device (typically be it's unique MAC address ID). The router will set aside the reserved address (for example,162.198.10.15), and never give this address out to any other device.

I tend to use a combination of the first and third method. The problem with setting the static address in the device (ATA or computer) itself is if the static address you had set has already been assigned to another device, because it asked for an IP address first. The best case is that the second one is not allowed to connect to the network. Sometimes misbehaved devices will cause problems on the network, constantly asking to be assigned their IP address.

Hope that makes it a little clearer.

[joyce]

Thanks for that. In this case, since the network has only two computers and pap, and one of the computers and the pap have been assigned seperate static ip addresses, I assume I will be all right.

VT has emailed me that they have made some adjustments on their end to my adapter this morning, and service seems to be better, at least I have had no more dropped calls. I am still experiencing some choppiness.

[DracoFelis]

What draco said at the end of his post is why I don't give devices that attach to my network static addresses. Rather, I allow my router control, by "reserving" a different static address for each device's MAC.
I tend to do that approach too, at least for some of my devices. But I have a router with the open source http://www.dd-wrt.com firmware in it, so its DHCP server is smart enough to do a static reservation (by MAC address). However, the DHCP server in many (most?) home routers isn't smart enough to handle static reservations.

So with many home routers, you have to use the "static IP" (on the device itself), if you want to avoid the addresses shifting around on their own (because with many home routers, their DHCP servers don't understand static reservations!

Thankfully, static IPs can be safely mixed with DHCP dynamic, if you do it correctly. The main thing you have to watch for, is to make sure that no static IP is ever attempted to be assigned by DHCP. And since almost all home routers out there let you set the top/bottom IP range that will be handled by their (built in) DHCP server, this is reasonably trivial to do.

For example, if your router is on the often popular 192.168.1.x network, than you could just tell your router's DHCP server to only hand out addresses 192.168.1.150 to 192.168.1.250. If you did that, than you would be free to safely assign (as a "static IP" in the devices themselves) all the addresses between 192.168.1.2 and 192.168.1.149. i.e. you give about 1/2 of your total LAN address space to your router's DHCP server, and leave the other 1/2 for static IPs you may want to assign to various specific computers or other network devices (including possibly your VT VoIP adapter).

As long as you are somewhat careful about doing this right, than no two devices will every be assigned the same IP address, and therefore no networking problems due to IP address conflicts!