Net unreachable

[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: 192.168.1.253
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

bash: /sbin/route: Input/output error

What can I do now?
(Edited)

[Harry Kuhman]

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

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]

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]

[
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]

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]

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]

... 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
ifconfig eth0 mtu 1500(or with whatever your NIC is if not eth0).
If that doesn't work, show us the output of
ifconfig eth0

[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
ifconfig eth0 mtu 1500(or with whatever your NIC is if not eth0).
If that doesn't work, show us the output of
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]

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.


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.


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).


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:


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:
....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:
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]

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 -
/sbin/route: Input/output error and no success when I ping either knoppix.net or www.google.com

Edit: I forgot to say that I couldn't as well ping 72.232.180.133

[Harry Kuhman]

and no success when I ping either knoppix.net or www.google.com
Last time I'm going to ask, what happens when you ping 72.232.180.133 ?

[Harry Kuhman]

Edit: I forgot to say that I couldn't as well ping 72.232.180.133
OK, now we're finally starting to learn something. As I say, you may or may not have a DNS issue, but since this ping should be able to get a response from knoppix.net without doing any DNS lookup, something else is going wrong here.

Which takes us back to the request to post the output of ifconfig, there is a fair chance that will tell us something.

If that isn't helpful, have you used ethereal/wireshark? It could be very handy to run ethereal (I think it's still call that in knoppix) and watch the packets. I'm at a loss to know why you can't ping this site by IP address.

As to other Linux versions not giving you this problem, it might be a kernel version issue. I know there are changes in the kernels that deal with the IPv4 / IPv6 issues that are different in different versions of the kernel, but I think I've only ever seen reports of that affecting DNS, not simple pings. It might also have something to do with your hardware (could be as simple as there being two ethernet interfaces in the computer and you're trying to talk to the one not connected to the modem). But you haven't given us any informantion about your computer and very little about your local network, so there is little we can do to help.

By the way, it's bad form to keep going back and editing old posts rather than making a new post. I wrote my response before you did your last edit. If I had not just happened to look back at the first page of the thread and see that you edited in an answer, I would not have known that you had responded or updated anything. A new post marks the thread as having new information to be read in it, an edit to an old post does not, and you may find yourself waiting a very long time before someone notices that you put the requested information in as an edit rather than a new post, if they catch it at all.

[sauravbhaumik]

Edit: I forgot to say that I couldn't as well ping 72.232.180.133
OK, now we're finally starting to learn something. As I say, you may or may not have a DNS issue, but since this ping should be able to get a response from knoppix.net without doing any DNS lookup, something else is going wrong here.

Okay, then could you please explain where the nameserver is necessary, and where it is not? It would enhance my knowledge.


Which takes us back to the request to post the output of ifconfig, there is a fair chance that will tell us something.
There is a problem doing that; as I said, from the cd, even the root is not able to write up anything on the hard disc. And as I don't have the net connexion from Knoppix, I can't understand how I'd manage to tell you the output - may be I have to write it up in a paper and then tell you - but that would increase the possibility of erroneous information.



If that isn't helpful, have you used ethereal/wireshark? It could be very handy to run ethereal (I think it's still call that in knoppix) and watch the packets. I'm at a loss to know why you can't ping this site by IP address.
Exactly I didn't use any protocol analyzer I believe; I just open up the "Konsole" and write "ping ....".
I can't actually understand why the Knoppix site is preferred for this ping (forgive me, you may find my knowledge too slender to bear with me).


As to other Linux versions not giving you this problem, it might be a kernel version issue.
The kernel of the Knoppix is 2.6.19
The release (what is it?) is 2.86.
The version is 5.1.1


I know there are changes in the kernels that deal with the IPv4 / IPv6 issues that are different in different versions of the kernel, but I think I've only ever seen reports of that affecting DNS, not simple pings. It might also have something to do with your hardware (could be as simple as there being two ethernet interfaces in the computer and you're trying to talk to the one not connected to the modem). But you haven't given us any informantion about your computer and very little about your local network, so there is little we can do to help.

I should tell you about my system. I've 2.4GHz P4 processor; 640 MB ram; my modem is MT882 sterlite, at which you may have a look here : http://calcuttatelephones.com/dataoneinstall/menu.html
I have only one ethernet interface. I connect the jack via lan port and use pppoe as the wan type (in modem configuration).
As to the netwrok and the service provider, you may have some information here http://calcuttatelephones.com/bbandservice.shtml



By the way, it's bad form to keep going back and editing old posts rather than making a new post. I wrote my response before you did your last edit. If I had not just happened to look back at the first page of the thread and see that you edited in an answer, I would not have known that you had responded or updated anything. A new post marks the thread as having new information to be read in it, an edit to an old post does not, and you may find yourself waiting a very long time before someone notices that you put the requested information in as an edit rather than a new post, if they catch it at all.

I am very sorry for that. But I did the last edit because I had not seen any response to the unedited post; and even after doing the edit, there was no response. It is only this morning that I'm seeing any kind of reply here.
However, I am very sorry if I've caused any inconvenience.

[JohnnyH]

...

Which takes us back to the request to post the output of ifconfig, there is a fair chance that will tell us something.
There is a problem doing that; as I said, from the cd, even the root is not able to write up anything on the hard disc. And as I don't have the net connexion from Knoppix, I can't understand how I'd manage to tell you the output - may be I have to write it up in a paper and then tell you - but that would increase the possibility of erroneous information....
I recommend that you write the output of
ifconfig eth0 (or with whatever your NIC is if not eth0) to paper and then tell us anyway.
(Does your machine have a floppy drive ? If so you could copy+paste the output from the screen into a text file, mount the floppy, save the file to the floppy, unmount the floppy, then load the file from the floppy into your internet-enabled system .)

[Harry Kuhman]

Okay, then could you please explain where the nameserver is necessary, and where it is not? It would enhance my knowledge.
DNS or name servers is what translates human readable names (URLs) like Knoppix.net to the numeric IP addresses that are in the address fields of packets as they are routed across the Internet. Rather than asking this and waiting for a response, you could have received plenty of information about it by doing a simple Google search, and it would have been much faster.


There is a problem doing that; as I said, from the cd, even the root is not able to write up anything on the hard disc. And as I don't have the net connexion from Knoppix, I can't understand how I'd manage to tell you the output - may be I have to write it up in a paper and then tell you - but that would increase the possibility of erroneous information.
You have been pointing out this "problem" for a couple of days now, but in the meantime we make no progress at all. I still suggest copying down the information and typing it back in. I guess that I could add the suggestion to preview your typing and proofread for errors.


Exactly I didn't use any protocol analyzer I believe; I just open up the "Konsole" and write "ping ....".
I can't actually understand why the Knoppix site is preferred for this ping (forgive me, you may find my knowledge too slender to bear with me).
The Knoppix site isn't preferred. The first time that I suggested this I simply suggested that you check any site by URL and IP address. You ignored that. So the second time I tried to give very detailed steps. I picked this site because it seemed like an obvious choice, and since I knew it responded to pings (most but not all sites do). And google.com would not have been a good example, since Google translates that one URL to many different IP addresses depending on the location of the user. You might not be able to get to my Google IP address, or it might not respond to a ping. Just better to use a system that I know should work.

Sounds like you don't have any experience with ethereal. I just didn't know what tools you were comfortable with. You did know enough to try the ping; many users with issues like yours don't. So it was worth asking.


I should tell you about my system. I've 2.4GHz P4 processor; 640 MB ram; my modem is MT882 sterlite, at which you may have a look here : http://calcuttatelephones.com/dataoneinstall/menu.html
I have only one ethernet interface. I connect the jack via lan port and use pppoe as the wan type (in modem configuration).
As to the netwrok and the service provider, you may have some information here http://calcuttatelephones.com/bbandservice.shtml
Its good to know your system. I have not yet taken the time to read the links that you provided. You mentioned pppoe. I din't quite follow what you were trying to tell me there. What I'm expecting is that your modem uses pppoe to talk to your ISP (likely over DSL rather than a cable system, although we have seen some non-DSL systems do use pppoe). I'm expecting that you are not running any pppoe software on your computer, when trying to use Knoppix or running any other OS, that the modem is taking care of pppoe for you. If I'm wrong about this please point that out, otherwise you are working similar to many of us (my router takes care of pppoe for me, as my router and my DSL modem are separate devices, but more modern equipment combines these two functions into one box).

[sauravbhaumik]

The output of ifconfig:


eth0 Link encap:Ethernet HWaddr 00:C0:26:21:34:7C
inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255
.255.0
inet6 addr:fe80::2c0:26ff:fe21:647c/64 Scope:Link
UP BROADCAST RUNNING MTU : 1500 Metric : 1
RX packets:1 errors:0 dropped:0 overruns:0 frame:0
TX packets:20 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:60(60.0b) TX bytes:3672(3.5KiB)
Interrupt:21 Base address:0x6c00

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU : 16436 Metric : 1
RX packets:14 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:700(700.0b) TX bytes:700(700.0b)

[sauravbhaumik]

Its good to know your system. I have not yet taken the time to read the links that you provided. You mentioned pppoe. I din't quite follow what you were trying to tell me there. What I'm expecting is that your modem uses pppoe to talk to your ISP (likely over DSL rather than a cable system, although we have seen some non-DSL systems do use pppoe). I'm expecting that you are not running any pppoe software on your computer, when trying to use Knoppix or running any other OS, that the modem is taking care of pppoe for you.

Yes; I am not running any pppoe software, my router takes care of the protocol.

[Harry Kuhman]

The output of ifconfig:.....
Overall this seems OK. It shows that you are sending packets and have received a packet (I'm guessing you did this right after booting into Knoppix and if you had waited a little there would have been even more packets). I don't know anything about the inet6 settings, I'm hoping that someone who does might join in. The MTU of 1500 might end up being a little high and as a pppoe user you may have to drop it (to around 1460), but that certainly isn't what is keeping you from pinging this website so lets ignore that for now.

Anyone else have any insight to offer?

One thing that you might want to try is shut down your computer, cycle power on the modem/router and then after the modem has come back up, boot Knoppix fresh (without starting any other operating system). There have been a few cases where cycling power or even resetting a router were needed to get things working and after the router was reset the problem was not seen again.

[Harry Kuhman]

One additional thought: since you are assigning your network parameters manually rather than by DHCP, next time you set them up use a different IP address in the same range. For example, assuming that it is not in use anywhere else in your local network, assign the IP address of 192.168.1.9 rather than 192.168.1.2. Keep the mask and the broadcast address the same as they are. This would help if there were some sort of strange IP lease problem with the 192.168.1.2 address. This shouldn't be needed, as the router should see the MAC address and understand what is happening, but there is no need to use the 192.168.1.2 address and since it doesn't seem to be working for outside traffic, change it.

If you were using DHCP then I don't think this would have been an issue.