traceroute bug ?

traceroute bug ?

[Gerold van Dijk]

Why can I NOT do a traceroute specifically within my own (sub)network

207.253.5.64/27

with any distribution of Linux??

Gerold@sicon-sr.com

Re: traceroute bug ?

[Valdis.Kletnieks]

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On Fri, 27 Jan 2006 15:38:23 -0300, Gerold van Dijk said:
> Why can I NOT do a traceroute specifically within my own (sub)network
> 
> 207.253.5.64/27
> 
> with any distribution of Linux??

OK.. I'll bite.  What happens when you try?  And why are you posting here - is
there *any* evidence that there is a Linux kernel bug involved?

The output of 'ifconfig' and 'netstat -r -n' would likely be helpful, as would
proof that the host(s) you're tracerouting from and to are *not* running a
firewall that interferes with the way traceroute functions. (It's amazing how
many people block all ICMP, then wonder why traceroute doesn't work... ;)

Watching the wire with 'tcpdump' and/or 'ethereal' can also help....



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Re: traceroute bug ?

[Jesper Juhl]

On 1/27/06, Gerold van Dijk <gerold@sicon-sr.com> wrote:
> Why can I NOT do a traceroute specifically within my own (sub)network
>
> 207.253.5.64/27
>
> with any distribution of Linux??
>

Because you configured your machines to drop icmp packets perhaps.
Some router on your network may be dropping icmp packets.
You've configured the network incorrectly.
There are several possible reasons, but I don't see what it has to do
with the kernel at this point?

--
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

Re: traceroute bug ?

[linux-os (Dick Johnson)]

On Fri, 27 Jan 2006, Gerold van Dijk wrote:

> Why can I NOT do a traceroute specifically within my own (sub)network
>
> 207.253.5.64/27
>
> with any distribution of Linux??
>
> Gerold@sicon-sr.com
>

Maybe you could explain? Traceroute works fine here....

These are all local:

Script started on Fri 27 Jan 2006 01:53:37 PM EST
[root@chaos client]# traceroute quark
traceroute to quark.analogic.com (10.112.50.12), 30 hops max, 38 byte packets
  1  quark (10.112.50.12)  0.145 ms  0.264 ms  0.174 ms
[root@chaos client]# traceroute boneserver
traceroute to boneserver.analogic.com (10.112.50.10), 30 hops max, 38 byte packets
  1  boneserver (10.112.50.10)  1.633 ms  0.135 ms  0.122 ms
[root@chaos client]# traceroute localhost
traceroute to localhost (127.0.0.1), 30 hops max, 38 byte packets
  1  localhost (127.0.0.1)  0.058 ms  0.045 ms  0.024 ms
[root@chaos client]# traceroute world.std.com
traceroute to world.std.com (192.74.137.5), 30 hops max, 38 byte packets
  1  def-10.112.50.1 (10.112.50.1)  0.625 ms  0.568 ms  0.549 ms
  2  * * *
  3  * * *
  4  *
[root@chaos client]# exit
Script done on Fri 27 Jan 2006 01:55:16 PM EST

Now, with the last one, I attempted to traceroute to something
non-local, outside. The Net Nazis closed all the ports
except mail, ftp, domain, and web so I can't send anything
outside to a non-standard port (like traceroute does) so
it fails with the "* * *"


Cheers,
Dick Johnson
Penguin : Linux version 2.6.13.4 on an i686 machine (5589.66 BogoMips).
Warning : 98.36% of all statistics are fiction.
.

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Thank you.

Re: traceroute bug ?

[Kyle Moffett]

On Jan 27, 2006, at 13:38, Gerold van Dijk wrote:
> Why can I NOT do a traceroute specifically within my own (sub)network
> 207.253.5.64/27

What part of "trace" "route" do you not understand?  If you are  
talking to your own subnet, there are no routers in between, so  
clearly there is nothing to trace.  A packet with TTL 0 is invalid,  
and a packet with TTL 1 will get to the host.

Cheers,
Kyle Moffett

--
Somone asked me why I work on this free (http://www.fsf.org/ 
philosophy/) software stuff and not get a real job. Charles Schulz  
had the best answer:

"Why do musicians compose symphonies and poets write poems? They do  
it because life wouldn't have any meaning for them if they didn't.  
That's why I draw cartoons. It's my life."
   -- Charles Schulz

OT: Re: traceroute bug ?

[ed]

On Fri, 27 Jan 2006 19:57:38 +0100
Jesper Juhl <jesper.juhl@gmail.com> wrote:

> On 1/27/06, Gerold van Dijk <gerold@sicon-sr.com> wrote:
> > Why can I NOT do a traceroute specifically within my own
> > (sub)network
> >
> > 207.253.5.64/27
> >
> > with any distribution of Linux??

> Because you configured your machines to drop icmp packets perhaps.
> Some router on your network may be dropping icmp packets.

I've known some bridging devices have filter rules too.

-- 
Regards, Ed http://www.usenix.org.uk
:%s/Open Source/Free Software/g

Re: traceroute bug ?

[Gerold van Dijk]

Dear Valdis et.al.,

thanks for biting! I really tested this thing thoroughly, with different 
distributions (Red Hat, SuSE 8.0 and 10.0) on different machines with the 
firewalls completely open, and without any router or switch involved: cross 
cable straight from one machine to another!

IF I ONLY CHANGE TO ANOTHER IP BLOCK (E.G. 206.253.5.64/24) OR A PRIVATE 
RANGE (E.G. 192.168.1.0/24) THE TRACEROUTE WORKS FINE! SO IT IS SPECIFICALLY 
THIS 207.253.5.0/24 BLOCK THAT DOES NOT TRACEROUTE WITHIN IT'S OWN RANGE!

Not only the subnetwork 207.253.5.64/27 but the whole class C block 
207.253.5.0/24 !?

Just to be complete: we CAN ping normally within this network!

But the traceroute simple displays "*  *  *" row after row!

Of course it is not that urgent a problem, cause what is the sense of doing 
a traceroute within your own network anyway? But I thought it might be 
useful to report this strange thing!

Thank you all for your time!

Regards,

Gerold H. van Dijk

Research & Training Manager

SICON; Suriname Information &
Communication Network

Verl.Gemenelandsweg 163
Paramaribo, Suriname
South America

(+597)    464791
(+597)    491510 (fax)
(+597)(0) 8579216 (gsm)

gerold@sicon-sr.com
gerold_vandijk@hotmail.com



On Fri, 27 Jan 2006 15:38:23 -0300, Gerold van Dijk said:
> Why can I NOT do a traceroute specifically within my own (sub)network
>
> 207.253.5.64/27
>
> with any distribution of Linux??

OK.. I'll bite.  What happens when you try?  And why are you posting here - 
is
there *any* evidence that there is a Linux kernel bug involved?

The output of 'ifconfig' and 'netstat -r -n' would likely be helpful, as 
would
proof that the host(s) you're tracerouting from and to are *not* running a
firewall that interferes with the way traceroute functions. (It's amazing 
how
many people block all ICMP, then wonder why traceroute doesn't work... ;)

Watching the wire with 'tcpdump' and/or 'ethereal' can also help....