[opensuse] Intermittent network access problem
Hi, i installed 11.1 (64bits) with KDE4.1 and recently i started having the following problem. It seems that as soon as the network starts (or i restart it) everything works fine. But after i wait a few seconds i simply can't ping any IPs, then after a few seconds i can ping them again and so on. There doesn't seem to be a fixed interval of time for this happen. One thing i noticed is that this happens less frequently when accessing IPs from the same network as me. Also, this doesn't happen on my home network, only at work. It looks liek routing trouble but the routing tables i get from the route command are the same at the time i have full network access and when the problem occurs. I'd really appreciate some ideas on this. Thanks. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Well, awnsering my own question and after 2 days of fighting this
problem some guy just came to my pc and solved it in two seconds.
It seems that someone here decided to use a fixed IP and chose the IP
that the dhcp was always assigning to my mac address. So, it was
simply an IP conflict.
Still, shouldn't a nice popup show up indicating this error ? That
would have saved my two days of problems.
On Wed, Jan 7, 2009 at 1:08 PM, Hugo Palma
Hi,
i installed 11.1 (64bits) with KDE4.1 and recently i started having the following problem. It seems that as soon as the network starts (or i restart it) everything works fine. But after i wait a few seconds i simply can't ping any IPs, then after a few seconds i can ping them again and so on. There doesn't seem to be a fixed interval of time for this happen.
One thing i noticed is that this happens less frequently when accessing IPs from the same network as me. Also, this doesn't happen on my home network, only at work.
It looks liek routing trouble but the routing tables i get from the route command are the same at the time i have full network access and when the problem occurs. I'd really appreciate some ideas on this.
Thanks.
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hugo Palma wrote:
Well, awnsering my own question and after 2 days of fighting this problem some guy just came to my pc and solved it in two seconds. It seems that someone here decided to use a fixed IP and chose the IP that the dhcp was always assigning to my mac address. So, it was simply an IP conflict.
Still, shouldn't a nice popup show up indicating this error ? That would have saved my two days of problems.
The problem is how to detect this situation. Some DHCP servers will ping an address, before issuing one, though I don't think that would work, on a renewal. Also, with switches, it's difficult to even watch the network, to see if someone has grabbed your address. All you can do, if you suspect this, is have someone else ping your IP address, to verify the MAC address. -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Wed, Jan 07, 2009 at 08:49:39AM -0500, James Knott wrote:
Hugo Palma wrote:
Well, awnsering my own question and after 2 days of fighting this problem some guy just came to my pc and solved it in two seconds. It seems that someone here decided to use a fixed IP and chose the IP that the dhcp was always assigning to my mac address. So, it was simply an IP conflict.
Still, shouldn't a nice popup show up indicating this error ? That would have saved my two days of problems.
The problem is how to detect this situation. Some DHCP servers will ping an address, before issuing one, though I don't think that would work, on a renewal. Also, with switches, it's difficult to even watch the network, to see if someone has grabbed your address. All you can do, if you suspect this, is have someone else ping your IP address, to verify the MAC address.
/etc/sysconfig/network/config:CHECK_DUPLICATE_IP has to be "yes" by default. At the moment this is no and this is wrong in the majority of cases. But a change will only address the issue on the low level. We also need to inform the user about the address conflict. Lars -- Lars Müller [ˈlaː(r)z ˈmʏlɐ] Samba Team SUSE Linux, Maxfeldstraße 5, 90409 Nürnberg, Germany
Lars Müller wrote:
On Wed, Jan 07, 2009 at 08:49:39AM -0500, James Knott wrote:
Hugo Palma wrote:
Well, awnsering my own question and after 2 days of fighting this problem some guy just came to my pc and solved it in two seconds. It seems that someone here decided to use a fixed IP and chose the IP that the dhcp was always assigning to my mac address. So, it was simply an IP conflict.
Still, shouldn't a nice popup show up indicating this error ? That would have saved my two days of problems.
The problem is how to detect this situation. Some DHCP servers will ping an address, before issuing one, though I don't think that would work, on a renewal. Also, with switches, it's difficult to even watch the network, to see if someone has grabbed your address. All you can do, if you suspect this, is have someone else ping your IP address, to verify the MAC address.
/etc/sysconfig/network/config:CHECK_DUPLICATE_IP has to be "yes" by default. At the moment this is no and this is wrong in the majority of cases.
But a change will only address the issue on the low level. We also need to inform the user about the address conflict.
Lars
I hadn't heard of that option. Is packet sockets enabled by default? What happens if a duplicate is found? What happens if a DHCP address has been assigned and then someone manually assigns that address on another computer, which IIRC is the case in the original message? -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Wed, Jan 07, 2009 at 09:35:23AM -0500, James Knott wrote: [ 8< ]
I hadn't heard of that option. Is packet sockets enabled by default?
In current kernels it's available as a module loadable at runtime.
What happens if a duplicate is found?
IIRC while setup a found duplicate causes the setup to stop.
What happens if a DHCP address has been assigned and then someone manually assigns that address on another computer, which IIRC is the case in the original message?
This is a more complex situation and I'm not sure if we're able to do anthing than logging and informing the user. Might we use dbus to pass a message to the end user sitting in front of the session? Lars -- Lars Müller [ˈlaː(r)z ˈmʏlɐ] Samba Team SUSE Linux, Maxfeldstraße 5, 90409 Nürnberg, Germany
Lars Müller wrote:
On Wed, Jan 07, 2009 at 09:35:23AM -0500, James Knott wrote: [ 8< ]
I hadn't heard of that option. Is packet sockets enabled by default?
In current kernels it's available as a module loadable at runtime.
What happens if a duplicate is found?
IIRC while setup a found duplicate causes the setup to stop.
What happens if a DHCP address has been assigned and then someone manually assigns that address on another computer, which IIRC is the case in the original message?
This is a more complex situation and I'm not sure if we're able to do anthing than logging and informing the user.
Might we use dbus to pass a message to the end user sitting in front of the session?
Lars
This still leaves the issue of the computer knowing there's a duplicate IP address on the network. When a duplicate IP is on the network, other computers, routers, servers etc., may get confused about which is the correct computer and send packets to the wrong one. How would the "real" one detect this, as opposed to some other network issue? Would a ping to it's address even get to the NIC? -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Can't the process that requests the IP from the DHCP server use ARP to
check if the returned IP is already taken just before registering
itself with that IP ?
On Thu, Jan 8, 2009 at 12:36 PM, James Knott
Lars Müller wrote:
On Wed, Jan 07, 2009 at 09:35:23AM -0500, James Knott wrote: [ 8< ]
I hadn't heard of that option. Is packet sockets enabled by default?
In current kernels it's available as a module loadable at runtime.
What happens if a duplicate is found?
IIRC while setup a found duplicate causes the setup to stop.
What happens if a DHCP address has been assigned and then someone manually assigns that address on another computer, which IIRC is the case in the original message?
This is a more complex situation and I'm not sure if we're able to do anthing than logging and informing the user.
Might we use dbus to pass a message to the end user sitting in front of the session?
Lars
This still leaves the issue of the computer knowing there's a duplicate IP address on the network. When a duplicate IP is on the network, other computers, routers, servers etc., may get confused about which is the correct computer and send packets to the wrong one. How would the "real" one detect this, as opposed to some other network issue? Would a ping to it's address even get to the NIC?
-- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hugo Palma wrote:
Can't the process that requests the IP from the DHCP server use ARP to check if the returned IP is already taken just before registering itself with that IP ?
As I mentioned earlier, the DHCP server may already do that, when first issuing an address. However, the OP was running into problems when he already had a valid IP address, which someone was then manually assigning to another computer. In this case, the computer would be asking itself. How far down the stack will the arp request for your own address go? -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
I know, but like you say, i was talking about the network process on
the linux box doing that and not relying on the dhcp server to check
it.
How do i test that ? I'm neither a linux or network expert user, just
know the concepts.
On Thu, Jan 8, 2009 at 3:10 PM, James Knott
Hugo Palma wrote:
Can't the process that requests the IP from the DHCP server use ARP to check if the returned IP is already taken just before registering itself with that IP ?
As I mentioned earlier, the DHCP server may already do that, when first issuing an address. However, the OP was running into problems when he already had a valid IP address, which someone was then manually assigning to another computer. In this case, the computer would be asking itself. How far down the stack will the arp request for your own address go?
-- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hugo Palma wrote:
Hi,
i installed 11.1 (64bits) with KDE4.1 and recently i started having the following problem. It seems that as soon as the network starts (or i restart it) everything works fine. But after i wait a few seconds i simply can't ping any IPs, then after a few seconds i can ping them again and so on. There doesn't seem to be a fixed interval of time for this happen.
One thing i noticed is that this happens less frequently when accessing IPs from the same network as me. Also, this doesn't happen on my home network, only at work.
It looks liek routing trouble but the routing tables i get from the route command are the same at the time i have full network access and when the problem occurs. I'd really appreciate some ideas on this.
Thanks.
What does traceroute say? Can you ping your own IP address? Flakey hardware? -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
I've solved it like i described in the previous email, thanks anyway
for replying.
Have one more question, where can i report this feature request ?
The feedback should have been much better, there wasn't even a log on
/var/log/NetworkManager indicating any kind of error.
On Wed, Jan 7, 2009 at 1:43 PM, James Knott
Hugo Palma wrote:
Hi,
i installed 11.1 (64bits) with KDE4.1 and recently i started having the following problem. It seems that as soon as the network starts (or i restart it) everything works fine. But after i wait a few seconds i simply can't ping any IPs, then after a few seconds i can ping them again and so on. There doesn't seem to be a fixed interval of time for this happen.
One thing i noticed is that this happens less frequently when accessing IPs from the same network as me. Also, this doesn't happen on my home network, only at work.
It looks liek routing trouble but the routing tables i get from the route command are the same at the time i have full network access and when the problem occurs. I'd really appreciate some ideas on this.
Thanks.
What does traceroute say? Can you ping your own IP address? Flakey hardware?
-- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (3)
-
Hugo Palma -
James Knott -
Lars Müller