| Author |
Message |
nick
Guest
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 Posted:
Wed Jan 12, 2005 9:03 pm Post subject:
Linux PC cannot ping, but Windows can? |
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I have a small network at home, using NAT. (192.168.1.*). I can ping, ssh
(everything) my office PC using the Windows PC at home. However, the Linux
PC always get the error: No such process.
Sounds very strange to me. Any clue? |
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Il Padrino
Guest
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| Posted:
Thu Jan 13, 2005 11:50 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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* On Wed, 12 Jan 2005 11:03:54 -0500, nick wrote:
| Quote: | I have a small network at home, using NAT. (192.168.1.*). I can ping, ssh
(everything) my office PC using the Windows PC at home. However, the Linux
PC always get the error: No such process.
Sounds very strange to me. Any clue?
|
Do you mean "SIOCDELRT : No Such Process" ?
Do you get any network card messages when you boot?
Fluffy |
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Il Padrino
Guest
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| Posted:
Thu Jan 13, 2005 5:24 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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* On Thu, 13 Jan 2005 09:30:57 -0500, nick wrote:
| Quote: | All my home PCs are using a Beklin Router/Wireless. I didn't notice any
network card messages - I didn't change anything.
I just get "ssh: connect to host 24.60.200.104 port 22: Connection timed
out" if I try to ssh from office pc to my home PC (I did the port forward on
my home router).
|
You connect from work and the connection times out. Does your work allow
outbound TCP port 22? Can you see the DNAT (port forward) in the logs
on your router or in the logs on your linux box... does your linux box
allow inbound port 22?
What is the output of /sbin/ifconfig -a on your linux box? |
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nick
Guest
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| Posted:
Thu Jan 13, 2005 7:30 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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"Il Padrino" <fuggedabowdit@baciamolemani.org> wrote in message
news:cs5na8$2ol$3@custnews.inweb.co.uk...
| Quote: | Do you mean "SIOCDELRT : No Such Process" ?
Do you get any network card messages when you boot?
Fluffy
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All my home PCs are using a Beklin Router/Wireless. I didn't notice any
network card messages - I didn't change anything.
I just get "ssh: connect to host 24.60.200.104 port 22: Connection timed
out" if I try to ssh from office pc to my home PC (I did the port forward on
my home router).
However, I get the following result if I run the following commands on my
Linux machine.
[bry@localhost Incoming]$ ssh 128.197.213.162
ssh: connect to host 128.197.213.162 port 22: No such process
[bry@localhost Incoming]$ ping 128.197.213.162
connect: No such process
[bry@localhost Incoming]$ rdesktop 128.197.213.162
ERROR: connect: No such process
[bry@localhost Incoming]$
But Windows PCs works fine (Windows PC can ping, terminal service my office
PC without any problem).
Could it be the firewall of my company? |
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nick
Guest
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| Posted:
Thu Jan 13, 2005 10:44 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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Should be my company's firewall because my Home Linux box can access PCs
that are not in my company and vice verse.
What's interesting is how my company firewall only block Linux PCs.
The ifconfig -a return on my home Linux PC:
eth0 Link encap:Ethernet HWaddr 00:10:5A:7A:5D:32
inet addr:192.168.2.200 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1067570 errors:0 dropped:0 overruns:0 frame:0
TX packets:1153199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:297279768 (283.5 MiB) TX bytes:767698853 (732.1 MiB)
Interrupt:9 Base address:0x2000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:5318 errors:0 dropped:0 overruns:0 frame:0
TX packets:5318 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4078594 (3.8 MiB) TX bytes:4078594 (3.8 MiB)
"Il Padrino" <fuggedabowdit@baciamolemani.org> wrote in message
news:cs6arv$8h3$1@custnews.inweb.co.uk...
| Quote: | * On Thu, 13 Jan 2005 09:30:57 -0500, nick wrote:
All my home PCs are using a Beklin Router/Wireless. I didn't notice any
network card messages - I didn't change anything.
I just get "ssh: connect to host 24.60.200.104 port 22: Connection timed
out" if I try to ssh from office pc to my home PC (I did the port forward
on
my home router).
You connect from work and the connection times out. Does your work allow
outbound TCP port 22? Can you see the DNAT (port forward) in the logs
on your router or in the logs on your linux box... does your linux box
allow inbound port 22?
What is the output of /sbin/ifconfig -a on your linux box?
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Moe Trin
Guest
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| Posted:
Fri Jan 14, 2005 5:59 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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In article <cs3hpo$be8$1@news3.bu.edu>, nick wrote:
| Quote: | I have a small network at home, using NAT. (192.168.1.*). I can ping, ssh
(everything) my office PC using the Windows PC at home. However, the Linux
PC always get the error: No such process.
|
Not enough information - sounds as if the Linux box isn't configured.
| Quote: | Sounds very strange to me. Any clue?
|
280428 Jan 13 13:55 HOWTO-INDEX
40490 Jun 22 2000 Home-Network-mini-HOWTO
684614 Nov 9 2003 IP-Masquerade-HOWTO
17605 Jul 21 22:32 Masquerading-Simple-HOWTO
It also helps to tell people what kind of setup you are using, and in the
case of Linux, what specific distribution and release.
Old guy |
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Il Padrino
Guest
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| Posted:
Fri Jan 14, 2005 9:53 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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* On Thu, 13 Jan 2005 12:44:08 -0500, nick wrote:
| Quote: | Should be my company's firewall because my Home Linux box can access PCs
that are not in my company and vice verse.
What's interesting is how my company firewall only block Linux PCs.
The ifconfig -a return on my home Linux PC:
eth0 Link encap:Ethernet HWaddr 00:10:5A:7A:5D:32
inet addr:192.168.2.200 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1067570 errors:0 dropped:0 overruns:0 frame:0
TX packets:1153199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:297279768 (283.5 MiB) TX bytes:767698853 (732.1 MiB)
Interrupt:9 Base address:0x2000
|
And what does /sbin/route display? and host.conf.. resolv.conf etc.. can
you ssh to www.[some-random-url-thatworks].co.uk? You should get
connection refused
Highly unlikely that they block "Linux boxen" since apart from certain
packet characteristics it would require a very fast CISCO with lots of
memory and some quite complicated rules.. and the linux box could be
modifed in seconds to circumvent anything in place.
I remember the days when ISPs tried to block people running masquerading
linux boxen based on outbound port addresses. Simple kernel recompile
and voila.. ISP defeated.
I'm sure you most likely have cocked something up somewhere.
Are you runing iptables? What are you outbound rules if so... |
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John Mason Jr
Guest
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| Posted:
Fri Jan 14, 2005 1:22 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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nick wrote:
| Quote: | Should be my company's firewall because my Home Linux box can access PCs
that are not in my company and vice verse.
What's interesting is how my company firewall only block Linux PCs.
|
<snip>
Try tcptraceroute, might help to see where things are blocked
http://michael.toren.net/code/tcptraceroute/
John |
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nick
Guest
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| Posted:
Mon Jan 17, 2005 11:21 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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Looks I didn't explain the issue well:
- Both my home Windows (192.168.2.89/24) and Linux (192.168.2.200/24) PC are
behind my home router.
- My home Windows PC can ping (ssh, do everything) my office PC and other
computers.
- But home Linux PC *cannot* ping (ssh, whatever) my office PC (error: xxxx:
No such process). However, it can ping (ssh, whatever) other computers
without any problem.
Looks the firewall in my office blocked only Linux hosts?
"nick" <nbdy9.removethis@hotmail.com> wrote in message
news:cs3hpo$be8$1@news3.bu.edu...
| Quote: | I have a small network at home, using NAT. (192.168.1.*). I can ping, ssh
(everything) my office PC using the Windows PC at home. However, the Linux
PC always get the error: No such process.
Sounds very strange to me. Any clue?
|
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Arthur Hagen
Guest
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| Posted:
Tue Jan 18, 2005 7:19 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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nick <nbdy9.removethis@hotmail.com> wrote:
| Quote: | Looks I didn't explain the issue well:
- Both my home Windows (192.168.2.89/24) and Linux (192.168.2.200/24)
PC are behind my home router.
- My home Windows PC can ping (ssh, do everything) my office PC and
other computers.
- But home Linux PC *cannot* ping (ssh, whatever) my office PC
(error: xxxx: No such process). However, it can ping (ssh, whatever)
other computers without any problem.
Looks the firewall in my office blocked only Linux hosts?
|
There's no way your office firewall can tell whether the ICMP ECHO_REQUEST
packet used in a ping comes from a Linux box or a Windows box.
Simply put, you have something configured wrong on your end, either on your
home router or your Linux box. Due to the error message, it's almost
certainly the latter. I would suspect ipfilter (although it would be useful
in narrowing down your problem to know exactly what "xxxx" is).
That it only happens when contacting your office I would *guess* is because
either your home router or your office router is misconfigured, and blocks
certain ICMP packets, most likely ICMP type 3 (host unreachable), and more
to the point, type 3 code 4 (packet needs to be fragmented, but the
do-not-fragment bit is set). This is used by PMTU path discovery and
blackhole detection, which is enabled by default on most Linux distros, but
has to be manually enabled under Windows.
Even if this is the root cause of the problem, the "No such process" errors
still signifies at least one misconfiguration on your Linux box.
--
*Art |
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nick
Guest
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| Posted:
Tue Jan 18, 2005 8:19 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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Thanks. I did more test:
I tried to ping two computers in my office on my home PCs. One of my office
computers is a web server running Win 2000 Server, another is a PC running
Win XP. They are in the same subnet.
My home Windows PC can ping both my office computers without any problem.
But my home Linux PC can only ping the Win 2000 Server (as well as other
hosts on Internet and other protocals). It got the error message "connect:
No such process" when ping my office Win XP PC only.
Also, my home PC can access my office WinXP PC without any problem if I use
"ssh -L 8888:My_Office_XP:80 another_host_on_the_net" to do port forward.
(by using http://localhost:8888). However, direct try http://My_Office_XP
will get "no such process".
Could you advice how to fix the problem if my home Linux's configuration has
problem? Or the firewall in my office is misconfigured?
Thanks,
"Arthur Hagen" <art@broomstick.com> wrote in message
news:cshrnd$jiq$1@cauldron.broomstick.com...
| Quote: | nick <nbdy9.removethis@hotmail.com> wrote:
Looks I didn't explain the issue well:
- Both my home Windows (192.168.2.89/24) and Linux (192.168.2.200/24)
PC are behind my home router.
- My home Windows PC can ping (ssh, do everything) my office PC and
other computers.
- But home Linux PC *cannot* ping (ssh, whatever) my office PC
(error: xxxx: No such process). However, it can ping (ssh, whatever)
other computers without any problem.
Looks the firewall in my office blocked only Linux hosts?
There's no way your office firewall can tell whether the ICMP ECHO_REQUEST
packet used in a ping comes from a Linux box or a Windows box.
Simply put, you have something configured wrong on your end, either on
your
home router or your Linux box. Due to the error message, it's almost
certainly the latter. I would suspect ipfilter (although it would be
useful
in narrowing down your problem to know exactly what "xxxx" is).
That it only happens when contacting your office I would *guess* is
because
either your home router or your office router is misconfigured, and blocks
certain ICMP packets, most likely ICMP type 3 (host unreachable), and more
to the point, type 3 code 4 (packet needs to be fragmented, but the
do-not-fragment bit is set). This is used by PMTU path discovery and
blackhole detection, which is enabled by default on most Linux distros,
but
has to be manually enabled under Windows.
Even if this is the root cause of the problem, the "No such process"
errors
still signifies at least one misconfiguration on your Linux box.
--
*Art
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Arthur Hagen
Guest
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| Posted:
Tue Jan 18, 2005 6:01 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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nick <nbdy9.removethis@hotmail.com> wrote:
[chop]
All of which is consistent with a misconfigured router that doesn't send
through ICMP Host Unreachable packets when the host tries to discover how
big packets it can send.
| Quote: | Could you advice how to fix the problem if my home Linux's
configuration has problem? Or the firewall in my office is
misconfigured?
|
All the necessary information for the latter is in my posting. Exactly how
to change the configuration is, of course, device specific, and I didn't
bring my crystal ball. Look for options like "block all ICMP" and make sure
that those options are NOT checked. At the very least, ICMP type 0, 1, 3,
4, 8 and 11 should be passed through.
For the former, the exact problem has to be determined before it can be
fixed. You could turn off PMTU discovery, and not see the errors again, but
that would be hiding the problem and not solving it.
Regards,
--
*Art |
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Eirik Seim
Guest
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| Posted:
Tue Jan 18, 2005 11:50 pm Post subject:
Re: Linux PC cannot ping, but Windows can? |
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On Mon, 17 Jan 2005 21:19:25 -0500, Arthur Hagen wrote:
[snip]
| Quote: | There's no way your office firewall can tell whether the ICMP ECHO_REQUEST
packet used in a ping comes from a Linux box or a Windows box.
|
While I agree it seems to be something wrong with the home router/fw
in this case, there are in fact ways a firewall can allow "linux" to
access certain network services, and deny "windows".
From http://www.openbsd.org/faq/pf/filter.html#osfp
pass in on $ext_if any os OpenBSD keep state
block in on $ext_if any os "Windows 2000"
block in on $ext_if any os "Linux 2.4 ts"
block in on $ext_if any os unknown
Google keywords: Passive Operating System Fingerprinting
--
New and exciting signature! |
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Arthur Hagen
Guest
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| Posted:
Wed Jan 19, 2005 4:07 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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Eirik Seim <eirik@mi.uib.no> wrote:
| Quote: | On Mon, 17 Jan 2005 21:19:25 -0500, Arthur Hagen wrote:
[snip]
There's no way your office firewall can tell whether the ICMP
ECHO_REQUEST packet used in a ping comes from a Linux box or a
Windows box.
While I agree it seems to be something wrong with the home router/fw
in this case, there are in fact ways a firewall can allow "linux" to
access certain network services, and deny "windows".
From http://www.openbsd.org/faq/pf/filter.html#osfp
pass in on $ext_if any os OpenBSD keep state
block in on $ext_if any os "Windows 2000"
block in on $ext_if any os "Linux 2.4 ts"
block in on $ext_if any os unknown
Google keywords: Passive Operating System Fingerprinting
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That would block TCP but not ICMP, though. And the OP has problems
*pinging* too.
--
*Art |
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Eirik Seim
Guest
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| Posted:
Thu Jan 20, 2005 2:18 am Post subject:
Re: Linux PC cannot ping, but Windows can? |
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On Tue, 18 Jan 2005 18:07:29 -0500, Arthur Hagen wrote:
| Quote: | Eirik Seim <eirik@mi.uib.no> wrote:
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[ about http://www.openbsd.org/faq/pf/filter.html#osfp ]
| Quote: | Google keywords: Passive Operating System Fingerprinting
That would block TCP but not ICMP, though. And the OP has problems
*pinging* too.
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Hrm, I must have missed the part where it said "will not work
on other protocols". Thanks for pointing that out.
--
New and exciting signature! |
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