Net unreachable

**sauravbhaumik** · 09-21-2007, 07:11 AM

I booted from the KNOPPIX V5.1.1CD, and got everything fine except the net.
I do Netcardconfig, and put the following:
IP: 192.168.1.2
Netmask: 255.255.255.0
Broadcast address: 192.168.1.253
Default gateway: 192.168.1.1
Nameserver: 208.67.222.222

And then is gives an error saying /sbin/route: Input/output error

And after that I can't ping www.google.com; but I can ping my modem's page 192.168.1.1

When as root I do /sbin/route it gives

Code:

bash: /sbin/route: Input/output error

What can I do now?
(Edited)

**Harry Kuhman** · 09-21-2007, 07:17 AM

Originally Posted by sauravbhaumik

I booted from the KNOPPIX V5.1.1CD, and got everything fine except the net.
I do Netcardconfig, and put the following:
IP: 192.168.1.2
Netmask: 255.255.255.0
Broadcast address: 192.168.1.153
Default gateway: 192.168.1.1
Nameserver: 208.67.222.222

And then is gives an error saying /sbin/route: Input/output error

And after that I can't ping www.google.com; but I can ping my modem's page 192.168.1.1

When as root I do /sbin/route it gives

Code:

bash: /sbin/route: Input/output error

What can I do now?

Where did you get that broadcast address? It's wrong, makes no sense based on the IP and net mask. Try 192.168.1.255 . However, that may well not be your only problem. You seem to have a local private network (based on the IP). Why do you have to do a netcardconfig at all and not just configure by DHCP?

**sauravbhaumik** · 09-21-2007, 07:21 AM

Originally Posted by Harry Kuhman

Where did you get that broadcast address? It's wrong, makes no sense based on the IP and net mask. Try 192.168.1.255 . However, that may well not be your only problem. You seem to have a local private network (based on the IP). Why do you have to do a netcardconfig at all and not just configure by DHCP?

Sorry for printing mistake!
I tried to write 192.168.1.253.
However, I tried the different Broadcast addresses:
192.168.1.255
192.168.1.253
192.168.1.254
255.255.255.255

None worked!

**sauravbhaumik** · 09-21-2007, 07:25 AM

Originally Posted by Harry Kuhman

[
Where did you get that broadcast address? It's wrong, makes no sense based on the IP and net mask. Try 192.168.1.255 . However, that may well not be your only problem. You seem to have a local private network (based on the IP). Why do you have to do a netcardconfig at all and not just configure by DHCP?

Actually, my internet is given by BSNL's ISP; it is NOT a private network I believe. I use mainly Ubuntu; and I put IP, netmask, default gateway and two dns. It works just fine!

But I can't understand what is going on in Knoppix.
In my modem configuration I always disable DHCP.

Could you kindly instruct me further?

**Harry Kuhman** · 09-21-2007, 07:29 AM

Originally Posted by sauravbhaumik

I tried to write 192.168.1.253.
However, I tried the different Broadcast addresses:
192.168.1.255
192.168.1.253
192.168.1.254
255.255.255.255

None worked!

Well, once again where did you get 192.168.1.253 ? It's wrong. With that mask and that IP, the broadcast address has to be 192.168.1.255. You are not likely to figure out what else is wrong if you use a bad broadcast address. Use the one I said to use. As I said, you may well have other problems, but you have to get the parameters that you are inputting correct.

So given that problem, I have to wonder if your DNS server is wrong also. But without more information about what you local network is made from I don't know that I can be of much more help. Trying pinging Internet sites that you know by both URL and IP address, if URL pings fail and IP address pings work then it is almost certainly a DNS issue. Got to get some sleep (2:30 AM here), so I will not be responding again for a while.

**sauravbhaumik** · 09-21-2007, 07:40 AM

Originally Posted by Harry Kuhman

Well, once again where did you get 192.168.1.253 ? It's wrong. With that mask and that IP, the broadcast address has to be 192.168.1.255. You are not likely to figure out what else is wrong if you use a bad broadcast address. Use the one I said to use. As I said, you may well have other problems, but you have to get the parameters that you are inputting correct.

So given that problem, I have to wonder if your DNS server is wrong also. But without more information about what you local network is made from I don't know that I can be of much more help. Trying pinging Internet sites that you know by both URL and IP address, if URL pings fail and IP address pings work then it is almost certainly a DNS issue. Got to get some sleep (2:30 AM here), so I will not be responding again for a while.

As I said, I tried the Broadcast address 192.168.1.1, as you said; but nothing improved.
However, as to the dns I'd say that it is open DNS; and in any OS with BSNL internet service provider these dns work fine!

Rather than Broadcast or dns, I would request you to concentrate (of course, after a good sleep) on this:
bash: /sbin/route: Input/output error

Kindly take cognisance.

**JohnnyH** · 09-21-2007, 08:56 AM

Originally Posted by sauravbhaumik

... And after that I can't ping www.google.com; but I can ping my modem's page 192.168.1.1 ...

... then try sending the command

Code:

ifconfig eth0 mtu 1500

(or with whatever your NIC is if not eth0).
If that doesn't work, show us the output of

Code:

ifconfig eth0

**sauravbhaumik** · 09-21-2007, 10:02 AM

Originally Posted by JohnnyH

Originally Posted by sauravbhaumik

... And after that I can't ping www.google.com; but I can ping my modem's page 192.168.1.1 ...

... then try sending the command

Code:

ifconfig eth0 mtu 1500

(or with whatever your NIC is if not eth0).
If that doesn't work, show us the output of

Code:

ifconfig eth0

Well, you see, I am working with the live cd. And the knoppix live cd doesn't allow me write anywhere on the hard disc. So I can't copy paste the output. Better you tell me how to do it (i.e. copy-paste on the hard disc). I don't have the net connexion from Knoppix ( that is "the" problem) and I have to write these messages from windows or Ubuntu.

**Harry Kuhman** · 09-21-2007, 02:00 PM

Originally Posted by sauravbhaumik

As I said, I tried the Broadcast address 192.168.1.1, as you said; but nothing improved.

I didn't say to use 192.168.1.1 for a broadcast address, I said 192.168.1.255. This is the only broadcast address that can be valid for that combination IP and mask. Your getting this wrong again does give me concern about what other numbers you have wrong.

Originally Posted by sauravbhaumik

Well, you see, I am working with the live cd. And the knoppix live cd doesn't allow me write anywhere on the hard disc. So I can't copy paste the output. Better you tell me how to do it (i.e. copy-paste on the hard disc). I don't have the net connexion from Knoppix ( that is "the" problem) and I have to write these messages from windows or Ubuntu.

There is not that much ifconfig information that you couldn't simply write it down and then type it in of you want help. Yes, there are other ways, but this would be the simplest. Of course, it's pretty important that you transcribe the data correctly.

Originally Posted by sauravbhaumik

In my modem configuration I always disable DHCP.

Why? I always enable it (even when I want to assign particular IP addresses to some of my systems).

Originally Posted by sauravbhaumik

Actually, my internet is given by BSNL's ISP; it is NOT a private network I believe.

ALL IP addresses in the 192.168.xxx.xxx range, as well as all 10.xxx.xxx.xxx addresses and 172.16.0.0 - 172.31.255.255 are private IP addresses. There are some other less common private IP ranges, but these first two are the most common. These addresses can not be routed to across the Internet. A router at the edge of the public Internet translates these private non-routable addresses to one or more assigned public IP addresses. This system is referred to as NAT. Some IP's cut corners by assigning private IP addresses (and do the NAT translation at the ISP's office on their routers). This saves them on needing lots of public addresses, but seriously restricts what the end user can do on the Internet. However, that doesn't seem to be the case, since you also say:

Originally Posted by sauravbhaumik

And after that I can't ping www.google.com; but I can ping my modem's page 192.168.1.1

Since you have a modem that has a setup page at 192.168.1.1, it seems extremely likely (ok, certain) that this modem is the NAT router and that it is being assigned a public IP address by the Internet Service Provider. It then gives out private 192.168.1.xxx addresses to all local systems and uses NAT translation to support one or more systems on the local private network. This is a very well understood and good technique (I wouldn't run a home system without a NAT router, I even travel with one just in case.) NAT protects you from a lot of inbound Internet attacks. The modem includes a NAT router and is the interface between your private network and the Internet. You modem likely will display to you your public IP address (as will some sites that you connect to such as www.ipchicken.com ), in your case I would suggest that your public IP address is something like 59.93.xxx.xxx. DO NOT use this address as you configure Linux, let the modem/router take care of that translation.

You seem to have completely ignored my suggestion:

Originally Posted by Harry Kuhman

....Trying pinging Internet sites that you know by both URL and IP address, if URL pings fail and IP address pings work then it is almost certainly a DNS issue.....

This seems strange, since you indicate that you know how to ping and you want help, but if any of it wasn't clear I would have expected you to ask, not ignore the suggestion. Let me restate it to make it extremely simple:
ping knoppix.net
That should fail, based on what you already told us. next
ping 72.232.180.133
If that works, you absolutely have a DNS issue. If the second ping here fails also, then you might still have a DNS issue, but you have some other problem that should be resolved first.

If you think that I'm ignoring your statement:

Originally Posted by sauravbhaumik

Rather than Broadcast or dns, I would request you to concentrate (of course, after a good sleep) on this:
bash: /sbin/route: Input/output error

you would be correct, I am.

**sauravbhaumik** · 09-21-2007, 04:01 PM

Originally Posted by Harry Kuhman

Originally Posted by sauravbhaumik

As I said, I tried the Broadcast address 192.168.1.1, as you said; but nothing improved.

I didn't say to use 192.168.1.1 for a broadcast address, I said 192.168.1.255. This is the only broadcast address that can be valid for that combination IP and mask. Your getting this wrong again does give me concern about what other numbers you have wrong.

Sorry for I've typed nonsense again!
I tried "as you instructed" i.e., I set as the broadcast address 192.168.1.255.
I may be typing wrong again, so let me restate:
I set as the Broadcast address 192.168.1.255

But the same problem again -

Code: