Kernel seems to be blocking messages

Kernel seems to be blocking messages

am 21.02.2004 01:45:39 von Paulo Jorge de Oliveira Cantante de Matos

Hi all,
I have a server running 2.6.2-rc1, and I was happily installing
vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
(don't ask me
why) every net connections seem to stop and get blocked. Now I cannot
make any socket connection. For example:

# ping localhost
PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
ping: sendmsg: Operation not permitted
....

Any ideas on how to unblock the situation?

Cheers,
--

Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
Instituto Superior Tecnico - Lisbon
Computer and Software Eng. - A.I.
- > http://mega.ist.utl.pt/~pocm
---
-> God had a deadline...
So, he wrote it all in Lisp!

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 21.02.2004 04:22:53 von asterr

I have seen this when iptables is running and pings are not permissioned.

On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:

> Hi all,
> I have a server running 2.6.2-rc1, and I was happily installing
> vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> (don't ask me
> why) every net connections seem to stop and get blocked. Now I cannot
> make any socket connection. For example:
>
> # ping localhost
> PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> ping: sendmsg: Operation not permitted
> ...
>
> Any ideas on how to unblock the situation?
>
> Cheers,
> --
>
> Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> Instituto Superior Tecnico - Lisbon
> Computer and Software Eng. - A.I.
> - > http://mega.ist.utl.pt/~pocm
> ---
> -> God had a deadline...
> So, he wrote it all in Lisp!
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 21.02.2004 04:22:53 von asterr

I have seen this when iptables is running and pings are not permissioned.

On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:

> Hi all,
> I have a server running 2.6.2-rc1, and I was happily installing
> vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> (don't ask me
> why) every net connections seem to stop and get blocked. Now I cannot
> make any socket connection. For example:
>
> # ping localhost
> PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> ping: sendmsg: Operation not permitted
> ...
>
> Any ideas on how to unblock the situation?
>
> Cheers,
> --
>
> Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> Instituto Superior Tecnico - Lisbon
> Computer and Software Eng. - A.I.
> - > http://mega.ist.utl.pt/~pocm
> ---
> -> God had a deadline...
> So, he wrote it all in Lisp!
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 21.02.2004 15:03:31 von Paulo Jorge de Oliveira Cantante de Matos

Hummm, that's very possible. I'm using iptables and I did tried
somethings with them... I'll see what's happening when I get home from
work.

Thanks a lot... :)
I'll then tell you if you were right.

Cheers,

Paulo Matos

On Sat, 2004-02-21 at 03:22, asterr wrote:
> I have seen this when iptables is running and pings are not permissioned.
>
> On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:
>
> > Hi all,
> > I have a server running 2.6.2-rc1, and I was happily installing
> > vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> > (don't ask me
> > why) every net connections seem to stop and get blocked. Now I cannot
> > make any socket connection. For example:
> >
> > # ping localhost
> > PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> > ping: sendmsg: Operation not permitted
> > ...
> >
> > Any ideas on how to unblock the situation?
> >
> > Cheers,
> > --
> >
> > Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> > Instituto Superior Tecnico - Lisbon
> > Computer and Software Eng. - A.I.
> > - > http://mega.ist.utl.pt/~pocm
> > ---
> > -> God had a deadline...
> > So, he wrote it all in Lisp!
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> >
> >
--

Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
Instituto Superior Tecnico - Lisbon
Computer and Software Eng. - A.I.
- > http://mega.ist.utl.pt/~pocm
---
-> God had a deadline...
So, he wrote it all in Lisp!

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 21.02.2004 15:03:31 von Paulo Jorge de Oliveira Cantante de Matos

Hummm, that's very possible. I'm using iptables and I did tried
somethings with them... I'll see what's happening when I get home from
work.

Thanks a lot... :)
I'll then tell you if you were right.

Cheers,

Paulo Matos

On Sat, 2004-02-21 at 03:22, asterr wrote:
> I have seen this when iptables is running and pings are not permissioned.
>
> On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:
>
> > Hi all,
> > I have a server running 2.6.2-rc1, and I was happily installing
> > vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> > (don't ask me
> > why) every net connections seem to stop and get blocked. Now I cannot
> > make any socket connection. For example:
> >
> > # ping localhost
> > PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> > ping: sendmsg: Operation not permitted
> > ...
> >
> > Any ideas on how to unblock the situation?
> >
> > Cheers,
> > --
> >
> > Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> > Instituto Superior Tecnico - Lisbon
> > Computer and Software Eng. - A.I.
> > - > http://mega.ist.utl.pt/~pocm
> > ---
> > -> God had a deadline...
> > So, he wrote it all in Lisp!
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> >
> >
--

Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
Instituto Superior Tecnico - Lisbon
Computer and Software Eng. - A.I.
- > http://mega.ist.utl.pt/~pocm
---
-> God had a deadline...
So, he wrote it all in Lisp!

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

RE: Kernel seems to be blocking messages

am 21.02.2004 16:11:35 von Armen Kaleshian

Paulo...

As Asterr suggested, you might have a iptable rules that are preventing data
to go through. To clear those rules, try the following:
Iptables -F
Iptables -X
Iptables -P INPUT ACCEPT
Iptables -P OUTPUT ACCEPT
Iptables -P FORWARD ACCEPT

The above wipes out any instance of any rules existing for the time being.
If you restart the server, they'll appear again. In that case, disable
iptables from starting by using chkconfig.

Good Luck! =D

--Armen

: -----Original Message-----
: From: linux-admin-owner@vger.kernel.org
: [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of Paulo
: Jorge de Oliveira Cantante de Matos
: Sent: Friday, 20 February, 2004 19:46
: To: linux-admin@vger.kernel.org; linux-newbie@vger.kernel.org
: Subject: Kernel seems to be blocking messages
:
: Hi all,
: I have a server running 2.6.2-rc1, and I was happily
: installing vpopmail and reading the vpopmail gentoo guide
: (www.gentoo.org). Somehow (don't ask me
: why) every net connections seem to stop and get blocked. Now
: I cannot make any socket connection. For example:
:
: # ping localhost
: PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
: ping: sendmsg: Operation not permitted
: ...
:
: Any ideas on how to unblock the situation?
:
: Cheers,
: --
:
: Paulo J. Matos : pocm [_at_] mega . ist . utl . pt Instituto
: Superior Tecnico - Lisbon Computer and Software Eng. - A.I.
: - > http://mega.ist.utl.pt/~pocm
: ---
: -> God had a deadline...
: So, he wrote it all in Lisp!
:
: -
: To unsubscribe from this list: send the line "unsubscribe
: linux-admin" in the body of a message to
: majordomo@vger.kernel.org More majordomo info at
: http://vger.kernel.org/majordomo-info.html
:


-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 22.02.2004 11:57:36 von Paulo Jorge de Oliveira Cantante de Matos

Hi,

You're right. The problem was the iptables configuration. I've done:
iptables -F
iptables -X

Then to share internet with my clients I've done:
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

however, it seems that it is not working, eth0 is my net connection.
This should work, right? Maybe I'm doing something wrong in my clients
config.

Cheers,

Paulo Matos


On Sat, 2004-02-21 at 03:22, asterr wrote:
> I have seen this when iptables is running and pings are not permissioned.
>
> On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:
>
> > Hi all,
> > I have a server running 2.6.2-rc1, and I was happily installing
> > vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> > (don't ask me
> > why) every net connections seem to stop and get blocked. Now I cannot
> > make any socket connection. For example:
> >
> > # ping localhost
> > PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> > ping: sendmsg: Operation not permitted
> > ...
> >
> > Any ideas on how to unblock the situation?
> >
> > Cheers,
> > --
> >
> > Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> > Instituto Superior Tecnico - Lisbon
> > Computer and Software Eng. - A.I.
> > - > http://mega.ist.utl.pt/~pocm
> > ---
> > -> God had a deadline...
> > So, he wrote it all in Lisp!
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> >
> >
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.linux-learn.org/faqs
--

Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
Instituto Superior Tecnico - Lisbon
Computer and Software Eng. - A.I.
- > http://mega.ist.utl.pt/~pocm
---
-> God had a deadline...
So, he wrote it all in Lisp!

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: Kernel seems to be blocking messages

am 22.02.2004 11:57:36 von Paulo Jorge de Oliveira Cantante de Matos

Hi,

You're right. The problem was the iptables configuration. I've done:
iptables -F
iptables -X

Then to share internet with my clients I've done:
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

however, it seems that it is not working, eth0 is my net connection.
This should work, right? Maybe I'm doing something wrong in my clients
config.

Cheers,

Paulo Matos


On Sat, 2004-02-21 at 03:22, asterr wrote:
> I have seen this when iptables is running and pings are not permissioned.
>
> On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de Matos wrote:
>
> > Hi all,
> > I have a server running 2.6.2-rc1, and I was happily installing
> > vpopmail and reading the vpopmail gentoo guide (www.gentoo.org). Somehow
> > (don't ask me
> > why) every net connections seem to stop and get blocked. Now I cannot
> > make any socket connection. For example:
> >
> > # ping localhost
> > PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
> > ping: sendmsg: Operation not permitted
> > ...
> >
> > Any ideas on how to unblock the situation?
> >
> > Cheers,
> > --
> >
> > Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
> > Instituto Superior Tecnico - Lisbon
> > Computer and Software Eng. - A.I.
> > - > http://mega.ist.utl.pt/~pocm
> > ---
> > -> God had a deadline...
> > So, he wrote it all in Lisp!
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> >
> >
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.linux-learn.org/faqs
--

Paulo J. Matos : pocm [_at_] mega . ist . utl . pt
Instituto Superior Tecnico - Lisbon
Computer and Software Eng. - A.I.
- > http://mega.ist.utl.pt/~pocm
---
-> God had a deadline...
So, he wrote it all in Lisp!

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

RE: Kernel seems to be blocking messages

am 22.02.2004 16:54:46 von Armen Kaleshian

There is one more change you need to make so that you are able to do NAT.

In /etc/sysctl.conf, you need to add/change the line:
net.ipv4.ip_forward = 1

The above might be set to zero, and if it is, change it to 1. Unfortunately,
for this change to take effect, you'd need to reboot the system, but there's
a quicker way. After you add the above line to the file, do the following:

echo "1" > /proc/sys/net/ipv4/ip_forward

If routing has been setup correctly for this machine, then any machine using
it as its router should be able to access the outside.

Make sure that you set some rules for outside traffic, or else potential
crackers could break the machine in little time, especially if you have
services running on the box.

Good Luck!


: -----Original Message-----
: From: linux-admin-owner@vger.kernel.org
: [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of Paulo
: Jorge de Oliveira Cantante de Matos
: Sent: Sunday, 22 February, 2004 05:58
: To: asterr
: Cc: linux-admin@vger.kernel.org; linux-newbie@vger.kernel.org
: Subject: Re: Kernel seems to be blocking messages
:
: Hi,
:
: You're right. The problem was the iptables configuration. I've done:
: iptables -F
: iptables -X
:
: Then to share internet with my clients I've done:
: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
:
: however, it seems that it is not working, eth0 is my net connection.
: This should work, right? Maybe I'm doing something wrong in
: my clients config.
:
: Cheers,
:
: Paulo Matos
:
:
: On Sat, 2004-02-21 at 03:22, asterr wrote:
: > I have seen this when iptables is running and pings are not
: permissioned.
: >
: > On Sat, 21 Feb 2004, Paulo Jorge de Oliveira Cantante de
: Matos wrote:
: >
: > > Hi all,
: > > I have a server running 2.6.2-rc1, and I was happily installing
: > > vpopmail and reading the vpopmail gentoo guide (www.gentoo.org).
: > > Somehow (don't ask me
: > > why) every net connections seem to stop and get blocked. Now I
: > > cannot make any socket connection. For example:
: > >
: > > # ping localhost
: > > PING descartes.geniousdomain (127.0.0.1) 56(84) bytes of data.
: > > ping: sendmsg: Operation not permitted ...
: > >
: > > Any ideas on how to unblock the situation?
: > >
: > > Cheers,
: > > --
: > >
: > > Paulo J. Matos : pocm [_at_] mega . ist . utl . pt Instituto
: > > Superior Tecnico - Lisbon Computer and Software Eng. - A.I.
: > > - > http://mega.ist.utl.pt/~pocm
: > > ---
: > > -> God had a deadline...
: > > So, he wrote it all in Lisp!
: > >
: > > -
: > > To unsubscribe from this list: send the line "unsubscribe
: > > linux-admin" in the body of a message to
: majordomo@vger.kernel.org
: > > More majordomo info at http://vger.kernel.org/majordomo-info.html
: > >
: > >
: > >
: >
: > -
: > To unsubscribe from this list: send the line "unsubscribe
: > linux-newbie" in the body of a message to majordomo@vger.kernel.org
: > More majordomo info at http://vger.kernel.org/majordomo-info.html
: > Please read the FAQ at http://www.linux-learn.org/faqs
: --
:
: Paulo J. Matos : pocm [_at_] mega . ist . utl . pt Instituto
: Superior Tecnico - Lisbon Computer and Software Eng. - A.I.
: - > http://mega.ist.utl.pt/~pocm
: ---
: -> God had a deadline...
: So, he wrote it all in Lisp!
:
: -
: To unsubscribe from this list: send the line "unsubscribe
: linux-admin" in the body of a message to
: majordomo@vger.kernel.org More majordomo info at
: http://vger.kernel.org/majordomo-info.html
:


-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs