# Ping problem linksys WAG54G



## zillah (Mar 18, 2005)

I have got this scenario. 

I have got my laptop with ADSL connection via LinkSys WAG54G, and My PC with dialup connection . 

From both PCs I can ping any sites on the net, but when I try to ping each other I could not (from PC to laptop, and from laptop to PC), I do not have any firewall on both PC, though I tried to ping gateway for linksys router from the PC, I could not. 

Is there any setting I have to be aware of it


----------



## boshic00 (Mar 3, 2005)

From a security point of view you really do not want the IP address of your computer to be pingable from the internet.

The reason why you cannot ping your laptop is that it has a private, non routeable IP address, generally 192.168.x.x. Your Linksys will also stop pings by default. The same goes for if you are trying to ping the LAN IP address of the Linksys. There is usually an option on the router to allow pings to it's WAN IP address or you can set it to forward all IP packets to your laptop.

As for being able to ping the PC there could be a number of issues including but not limited to...

Your ISP is blocking the pings
Your ISP gave you a non routable IP address

But as I said earlier, you really really do not want your computers to be pingable from the internet. You really should also invest in some firewall software for your computers, especially the PC.

Hope this helps


----------



## zillah (Mar 18, 2005)

Thanks boshic00

1-But I should be able to ping other PC on the same LAN, it shouldnot be any restriction to do that.

2-Who can I access my PCs remotly, if I disabled ping?



> There is usually an option on the router to allow pings to it's WAN IP address or you can set it to forward all IP packets to your laptop.


what is that option?




> Your ISP is blocking the pings


But I can ping any site on net, as I mentioned



> Your ISP gave you a non routable IP address


I have been assigned public IP address dynamically, and I believe that all public IP addresses are routable,,,Am I right?


----------



## boshic00 (Mar 3, 2005)

OK,

Responses...

1 You are correct, if they are on the same LAN you should be able to ping the other computer, however, you mentioned that only one of the computers is connected to router, the other is connected via dial up. If you connected both computers to the router and there are no firelwalls on either computer you should be able to ping between them.

2 By dissabling pings from the internet you make it harder for the bad guys to know that your PC is there. Your computer can still be vulnerable to other attacks if your computer does not have a well configured firewall.

3 I do not have the same model Linksys router as you but under Security mine has an option to allow annonymous internet requests. I have never enabled this but I believe it will allow users on the internet to ping your router and also access the HTML configuration pages.

4 A good ISP will block pings coming into their network form their connections to the internet proper. They will generally allow you to ping out, some do not even allow that.

5 What is the IP address that your ISP gave you? It is possible that they gave you a 10.x.x.x, 172.x.x.x or 192.168.x.x IP address, these addresses are non-routable. To get around this they will perform NAT for you. It all depends on your ISP. Even if the ISP did give you a public IP address it does not mean that it is routable on the WWW, they can be proxying/NATing public IPs also. A lot of private enterprises do this to protect their public IPs from being known on the internet.


----------



## johnwill (Sep 26, 2002)

boshic00 said:


> 4 A good ISP will block pings coming into their network form their connections to the internet proper. They will generally allow you to ping out, some do not even allow that.


HUH? I would drop an ISP that blocked pings coming in like a hot rock! That precludes you having any kind of server, or even using it for diagnostics. And blocking pings going out is even more ridiculous! I know of no ISP that does either, and I'm happy that I don't! What could possibly be the reason to block outgoing pings?


----------



## boshic00 (Mar 3, 2005)

I do not know of any ISPs that will block outgoing pings either, but ISPs have been known to block incoming pings especially if there have been issues with DDOS attacks. Blocking pings into your computer does not stop users accessing your services, web, ftp, ssh etc. And you can also set up monitoring on a different port if you are having issues with ping.


----------



## johnwill (Sep 26, 2002)

However, what's the first thing you do when you're trying to determine if a server is available? PING, that's what.


----------



## boshic00 (Mar 3, 2005)

I agree... it is pretty much the first thing I try followed by a traceroute to find out where things die, but there again, a lot of providers block traceroute too


----------



## johnwill (Sep 26, 2002)

Well, neither Verizon or Comcast do any of that around here, I don't normally run across other suppliers.


----------



## zillah (Mar 18, 2005)

> You are correct, if they are on the same LAN you should be able to ping the other computer


But what you said, is that :



> The same goes for if you are trying to ping the LAN IP address of the Linksys


My uderstanding "The same goes--" is the same ping problem. 

But this is what I disagree with, because we shouldn't have any ping problem with PCs on our LAN.


----------



## boshic00 (Mar 3, 2005)

Hi,

I am obviosly not understanding the way your network is set up. Can you explain what is connected to what and how and what the IP is of each PC?

My understanding from your first post was that one PC was connected to the router and accessed the internet via that router and that the other PC was not connected to the router and connected to the internet via dialup. From my understanding the computers are not on the same LAN and therefore you will not be able to ping between them if one is behind a NATing router.

Thanks


----------



## zillah (Mar 18, 2005)

> I am obviosly not understanding the way your network is set up


You did understand, your description is exactly how my network is set up.




> From my understanding the computers are not on the same LAN and therefore you will not be able to ping between them if one is behind a NATing router.


.

Yes I agree, but I am not trying to ping the private IP (LAN Address), I am trying to ping public IP assigned to my router by ISP via DHCP.


----------



## boshic00 (Mar 3, 2005)

OK, so you want to be able to ping from one machine to the other over the internet?

What are the two IPs involved?

We will have to enable your router to respond to pings, I do not know how to do this for your specific router, but my Netgear has an option to respond to ping on internet port under the WAN setup page. I am sure you can do this for a Linksys also as I used to have one.


----------



## zillah (Mar 18, 2005)

> What are the two IPs involved?


Public IP addresses, for the dialup is 214.164.X.X, and for ADLS router is 215.40.X.X



> I am sure you can do this for a Linksys also as I used to have one.


I will try and let you know. You meant I have to enable ping (echo ping), Didn't you?


----------



## boshic00 (Mar 3, 2005)

Yes, you will need to enable ping/echo ping/ICMP.

Both of those subnets appear to belong to the Department of Defense, according to ARIN. Which ISPs are you using?


----------



## zillah (Mar 18, 2005)

> Both of those subnets appear to belong to the Department of Defense, according to ARIN. Which ISPs are you using?


Actually when I wrote the IP addresses, I was not at home, therefore I tried to remembere what are they, the real IP addresses with value of : 217.165.X.X for ADSL router, and the real IP address of dialup: 213.43.x.x


I copied and pasted the screen for linksys under security*:*


*Firewall Protection::*

Enabled Disabled 


*Additional Filters: *  

Filter Proxy Filter Cookies 

Filter Java Applets Filter ActiveX 

Filter Multicast 


*Block WAN requests:* 

Block Anonymous Internet Requests 



Fisrt- 
I tried unblock last option 



Second- 
I tried to ping from desktop (via dialup), to laptop (ADSL router), still I can not ping!!!!!!, I tried to ping from laptop (ADSL router) to desktop (via dialup), I could ? Why?

Third- 
Enabling and disabling ping on ADSL router it *should affect * only IP address of the router itself, it *should not * affect the gateway of the router,,,,Am I right ? If so, why can not I ping gateway of the router from Desktop (dialup)?


----------



## boshic00 (Mar 3, 2005)

OK, sorry for the delay in response...

So you can now ping in one direction but not the other. Have you tried to access the IP address associated with the router using a web browser, when the block anonymous internet requests is disabled? If that works but you still cannot ping I would try dissabling the firewall, but would not leave it down permanently. Another thing you could try, though I do not recommend this, is to dissable the firewall on both the router and your computer and direct your router to use your computer's IP address as the DMZ.

You are right, you have no control over the gateway of the router. That is controlled by your ISP.


----------



## zillah (Mar 18, 2005)

1-


> Have you tried to access the IP address associated with the router using a web browser, when the block anonymous internet requests is disabled


I tried this, it did not work.


2-


> I would try dissabling the firewall, but would not leave it down permanently


I tried this, with disabling the option above (when the block anonymous internet requests is disabled),,,,it did not work.


3-


> Another thing you could try, though I do not recommend this, is to dissable the firewall on both the router and your computer and direct your router to use your computer's IP address as the DMZ.


I have not firewall on my PCs (Desktop and laptop). Could you please expalin this :

direct your router to use your computer's IP address as the DMZ.


4- Still I can ping from the laptop (ADSL router) to Desktop (dialup ), but not vice versa!!!


5- Why cannot I ping DNS for my router (DNS:194.227.x.x), from Desktop (Dialup)?!!!!. It should work without any problem


----------



## johnwill (Sep 26, 2002)

Are you really trying to ping the DNS address? You want to ping the router's IP address, not the DNS address.


----------



## zillah (Mar 18, 2005)

> Are you really trying to ping the DNS address? You want to ping the router's IP address, not the DNS address.


I mentioned this, just to let you know. Not because I am looking to ping DNS


----------

