Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-07-10 15:09:25 -0600, Bob Proulx wrote: but I think that maybe you simply need to remove all of the 'auto' and 'allow-hotplug' lines from the file. Then it won't be started automatically. But I want it to be started automatically on some networks. This is very important as I don't always have physical access to my machine. Personally I think *only* starting it on networks that will use it makes more sense than *always* starting it and killing it off if the configuration decides this is not a dhcp network. This is exactly what my interfaces file does: auto eth0 eth1 mapping eth* script /usr/local/sbin/map-scheme iface eth-casc inet static address 83.149.208.176 netmask 255.255.255.192 broadcast 83.149.208.191 gateway 83.149.208.129 iface eth-dhcp inet dhcp iface eth-ensl inet dhcp iface eth-loria inet dhcp iface eth-nerim inet static address 192.168.0.3 netmask 255.255.255.0 gateway 192.168.0.1 iface eth-uka inet static address 172.20.22.84 netmask 255.255.248.0 broadcast 172.20.23.255 The suffix (casc, dhcp, etc.) is obtained from netenv. On the other networks (i.e. other suffixes), there's no mapping iface, i.e. the Ethernet card is not used. (Note: I use auto eth0 eth1 because the device name depends on the kernel version, and the map-scheme script looks at the MAC address to decide which one should be used.) But if a DHCP client is still running (from the previous environment), it reconfigures the network interface. I've already had this problem, so I know I must kill the DHCP client. This sounds like new information. I am used to always getting to a clean state and then moving through the state diagram to the desired state for that network. Well, killing the DHCP client is a way to have a clean state before reconfiguring the network. Also, even if DHCP is always used, letting the network to be reconfigured automatically when switching network may lead to lost mail for instance, due to race condition. The correct steps are: 1. Bring the network interface down. 2. Update various configuration files (e.g. the new smarthost for the mail). 3. Bring the network interface up. in this order. If step 2 is done after step 3, problems can occur. I believe that is fairly standard in Etch. See the /etc/network/*.d/* files for postfix for example. Unfortunately, exim4[*] doesn't have anything in these directories. Now, I don't think they will solve the problem I've described: if the DHCP client detects a different server and reconfigures the interface, it will not run the scripts from the /etc/network/*.d/* directories (because it works at another level), will it? [*] which I use because this is (was) the default on Debian. -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-07-03 17:33:46 -0600, Bob Proulx wrote: Vincent Lefevre wrote: But then, I don't see why I should use 'allow-hotplug eth0' instead of 'auto eth0'. It is not required to use allow-hotplug but that is the new way of doing things. The new debian-installer will set things up with allow-hotplug. Then machines such as laptops with a pcmcia slot or usb device can have network devices go online and offline in a nice hotplug fashion. Same for any other hotpluggable device. There seems to be a difference. When I used 'allow-hotplug eth0', pump was no longer running. I've done the same test with 'auto eth0' (i.e. boot with the network cable unplugged, then plugged it in again), and 'pump -i eth0' was still running... but after 5 minutes, the interface was still down. 'pump -i eth0 --status' was saying 'Operation failed.' (at boot time, this was normal since the cable was unplugged, but this doesn't explain why it was still saying that more than 5 minutes after plugging in the cable). Running 'pump -i eth0' brought the interface up. So, 1. 'allow-hotplug ath0' doesn't seem to work (either it doesn't start pump or it kills it), but I doubt that pump is the cause since it is still running if I use 'auto eth0'. 2. There's a bug in pump, as it doesn't seem to try again if DHCP is available. -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
Vincent Lefevre wrote: Bob Proulx wrote: That bug may still be open but I have never seen it in any configuration. I think that bug may no longer be there but no one has verified it to root cause and so it has not been closed. There is no discussion after the first report. Is anyone else seeing that bug? I would guess not. I saw it 3 years later. See the merged bug 208605 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=208605 where there is a discussion. Good information. Thanks for posting that pointer. It may be enough if you always use DHCP. But there are still networks without DHCP. Of course. The Etch default is to use network-manager to bring network devices online. See /usr/share/doc/network-manager/README.Debian for full details. I don't want something graphical. Being a non-graphical person myself I can't argue with that. Description: Configure your system for different network environments There are actually a large number of network configuration packages and they have pluses and minuses to each of them. I don't think there is one size fits all for any of them. Some will intrinsically work better in some situations than others will. but I think that maybe you simply need to remove all of the 'auto' and 'allow-hotplug' lines from the file. Then it won't be started automatically. But I want it to be started automatically on some networks. This is very important as I don't always have physical access to my machine. Personally I think *only* starting it on networks that will use it makes more sense than *always* starting it and killing it off if the configuration decides this is not a dhcp network. However it is just a program and if killing it off works better for you then go for it. The netenv utility allows that. Sounds good. Then you won't have to kill the dhcp clients. This is unfortunately wrong. As I've said, there are networks without DHCP (or one which I don't want to use), on which I need to use iface ... inet static. As stated I disagree that it is wrong. If you need it then run it. If you don't need it then don't run it. In your case if you want to start it then decide it needs to be stopped then okay too. Browsing through the alternative packages that are available will show that many people have different ideas on the best way to get the job done. But if a DHCP client is still running (from the previous environment), it reconfigures the network interface. I've already had this problem, so I know I must kill the DHCP client. This sounds like new information. I am used to always getting to a clean state and then moving through the state diagram to the desired state for that network. Dragging forward a previous state would be different. But I don't think it is worth hashing out the details here. You understand what is going on for your situation. I think you have it working for you. Life sounds good! :-) Also, even if DHCP is always used, letting the network to be reconfigured automatically when switching network may lead to lost mail for instance, due to race condition. The correct steps are: 1. Bring the network interface down. 2. Update various configuration files (e.g. the new smarthost for the mail). 3. Bring the network interface up. in this order. If step 2 is done after step 3, problems can occur. I believe that is fairly standard in Etch. See the /etc/network/*.d/* files for postfix for example. Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-07-03 17:44:03 -0600, Bob Proulx wrote: Vincent Lefevre wrote: The problem with dhclient is that it disconfigures the loopback interface under some conditions. A bug is still open after 7 years! http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=65718 That bug may still be open but I have never seen it in any configuration. I think that bug may no longer be there but no one has verified it to root cause and so it has not been closed. There is no discussion after the first report. Is anyone else seeing that bug? I would guess not. I saw it 3 years later. See the merged bug 208605 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=208605 where there is a discussion. Also I need to control whether a DHCP client is running or not, Hmm... Usually saying 'iface eth0 inet dhcp' is enough. When ifupdown runs it will automatically start the installed dhcp client. For me when I did not want that I simply did not configure that device as an 'auto' device and then I could control it completely. It may be enough if you always use DHCP. But there are still networks without DHCP. The Etch default is to use network-manager to bring network devices online. See /usr/share/doc/network-manager/README.Debian for full details. I don't want something graphical. because on another machine (a laptop) I use netenv and DHCP is not used on some networks (BTW, I've already have a killall pump in my netenv scripts on this laptop, and I could probably do the same thing with dhclient). I have not used netenv and I don't know about it Description: Configure your system for different network environments Netenv lets you choose your network environment (and other things) upon boot, which is useful for notebook computers. The difference to similar packages is that it doesn't try to autodetect your environment, but expects your input. You can, however, specify a default or pass it a parameter from the boot prompt to allow for unattended boot. You can also use it to switch between environments without rebooting. Note that there is a timeout, so that the machine will keep the same network environment if it reboots while I'm not in front of it. but I think that maybe you simply need to remove all of the 'auto' and 'allow-hotplug' lines from the file. Then it won't be started automatically. But I want it to be started automatically on some networks. This is very important as I don't always have physical access to my machine. The netenv utility allows that. Then you won't have to kill the dhcp clients. This is unfortunately wrong. As I've said, there are networks without DHCP (or one which I don't want to use), on which I need to use iface ... inet static. But if a DHCP client is still running (from the previous environment), it reconfigures the network interface. I've already had this problem, so I know I must kill the DHCP client. Also, even if DHCP is always used, letting the network to be reconfigured automatically when switching network may lead to lost mail for instance, due to race condition. The correct steps are: 1. Bring the network interface down. 2. Update various configuration files (e.g. the new smarthost for the mail). 3. Bring the network interface up. in this order. If step 2 is done after step 3, problems can occur. -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-07-01 15:57:23 -0400, Celejar wrote: I use dhclient (I know you said in a different message in this thread that you don't like it), which by default does a bunch of DHCPDISCOVERS, and if they all fail, it then goes to sleep (for 5 minutes by default), and then begins the process again when it wakes up. This behavior seems to be exactly what you need; unfortunately, I don't know anything about pump. The problem with dhclient is that it disconfigures the loopback interface under some conditions. A bug is still open after 7 years! http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=65718 Users reported other problems, but perhaps they have been fixed now (I switched from dhclient to pump 3 years ago). Also I need to control whether a DHCP client is running or not, because on another machine (a laptop) I use netenv and DHCP is not used on some networks (BTW, I've already have a killall pump in my netenv scripts on this laptop, and I could probably do the same thing with dhclient). -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-07-02 23:16:22 -0600, Bob Proulx wrote: Vincent Lefevre wrote: This doesn't work. Probably a kernel problem then. I've reported the bug. I doubt this would be related to the kernel in any way. Since this works for other people I can only assume that something specific to your system is messed up. You will need to debug it. Sorry but that is the best advice I can give. OK, I confirm that this is a problem with pump (its man page sucks and I didn't know how it should have behaved) on this particular machine. But then, I don't see why I should use 'allow-hotplug eth0' instead of 'auto eth0'. Normally a dhcp client will retry. This is true of both dhcp3 and pump. On my laptop, when I type pump -i eth0 (the device exists but is down and not connected), I get the error message Operation failed. (as expected), but pump -i eth0 is still shown by ps. So, this confirms what you are saying. But on the other machine (on which I have the problem I mentioned at the beginning of this thread), when I type pump -i eth1 (again, the device exists but is down and not connected), I also get the error message Operation failed. as expected, but pump -i eth1 is no longer running. I think this can explain my problem if it can be confirmed on eth0 too (I'll have to try that). Note: I do not have a /etc/pump.conf file on any machine. There should messages in the /var/log/syslog file with some information about what is happening. I just have: Jul 3 14:11:22 vin pumpd[2478]: PUMP: sending discover And on June 28/29, /var/log/syslog doesn't show anything about pumpd at the time the Ethernet cable was disconnected. Hmm... I have had problems with pump in the past and recommend dhcp3. Basically dhcp3 is the ISC code and pump is the Red Hat code. In my experience people coming from Red Hat to Debian usually prefer pump because it is what they know. In particular, this was a discussion in debian-user-french in June 2004, so with Debian users. -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
Vincent Lefevre wrote: But then, I don't see why I should use 'allow-hotplug eth0' instead of 'auto eth0'. It is not required to use allow-hotplug but that is the new way of doing things. The new debian-installer will set things up with allow-hotplug. Then machines such as laptops with a pcmcia slot or usb device can have network devices go online and offline in a nice hotplug fashion. Same for any other hotpluggable device. But this is not required. You could use 'auto' and then things will happen at boot time (only) the same as it used to do before. For a machine without any hotplugable devices then it shouldn't matter which way things are configured and both should just work. Both configurations just work for me. Note that '/etc/init.d/networking restart' only affects 'auto' devices and not 'allow-hotplug' devices. This makes sense since this is the old way of starting things up at boot time but it can catch people off guard when they have not been exposed to this before. I am sure there is a way to trigger the udev scripts to run the hotplug device scripts too but I don't know how at this moment. But on the other machine (on which I have the problem I mentioned at the beginning of this thread), when I type pump -i eth1 (again, the device exists but is down and not connected), I also get the error message Operation failed. as expected, but pump -i eth1 is no longer running. I think this can explain my problem if it can be confirmed on eth0 too (I'll have to try that). I am not sure why operation failed is expected. I expect that to succeed. Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
Vincent Lefevre wrote: The problem with dhclient is that it disconfigures the loopback interface under some conditions. A bug is still open after 7 years! http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=65718 That bug may still be open but I have never seen it in any configuration. I think that bug may no longer be there but no one has verified it to root cause and so it has not been closed. There is no discussion after the first report. Is anyone else seeing that bug? I would guess not. Also I need to control whether a DHCP client is running or not, Hmm... Usually saying 'iface eth0 inet dhcp' is enough. When ifupdown runs it will automatically start the installed dhcp client. For me when I did not want that I simply did not configure that device as an 'auto' device and then I could control it completely. The Etch default is to use network-manager to bring network devices online. See /usr/share/doc/network-manager/README.Debian for full details. because on another machine (a laptop) I use netenv and DHCP is not used on some networks (BTW, I've already have a killall pump in my netenv scripts on this laptop, and I could probably do the same thing with dhclient). I have not used netenv and I don't know about it but I think that maybe you simply need to remove all of the 'auto' and 'allow-hotplug' lines from the file. Then it won't be started automatically. Then you won't have to kill the dhcp clients. Then you can use netenv to start up the device the same as you have been doing. I would guess anyway. That seems cleaner. Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On Thu, 28 Jun 2007 22:47:09 +0200 Vincent Lefevre [EMAIL PROTECTED] wrote: On a machine in a local network, I have in my /etc/network/interfaces file: auto eth0 iface eth0 inet dhcp But after a power outage, my machine sometimes restarts while the network isn't available yet. In this case, I can no longer ssh to it. And I can't reboot it remotely. How can I make pump (the DHCP client I'm using) to try again periodically? I think I can write a script that tests if pump is running (with the ps command) and can run this script by cron. But is there a better way? I use dhclient (I know you said in a different message in this thread that you don't like it), which by default does a bunch of DHCPDISCOVERS, and if they all fail, it then goes to sleep (for 5 minutes by default), and then begins the process again when it wakes up. This behavior seems to be exactly what you need; unfortunately, I don't know anything about pump. Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ Celejar -- mailmin.sourceforge.net - remote access via secure (OpenPGP) email ssuds.sourceforge.net - A Simple Sudoku Solver and Generator
Re: restarting pump (DHCP) automatically when network unavailable at boot time
Vincent Lefevre wrote: This doesn't work. Probably a kernel problem then. I've reported the bug. I doubt this would be related to the kernel in any way. Since this works for other people I can only assume that something specific to your system is messed up. You will need to debug it. Sorry but that is the best advice I can give. How can I make pump (the DHCP client I'm using) to try again periodically? I think it should already be trying again periodically. It doesn't, even with 'allow-hotplug eth0'. Normally a dhcp client will retry. This is true of both dhcp3 and pump. There should messages in the /var/log/syslog file with some information about what is happening. Perhaps the timeout is very long. You might try dhcp3-client instead. I have had good luck with it. I had problems with it in the past and users recommended pump instead. Hmm... I have had problems with pump in the past and recommend dhcp3. Basically dhcp3 is the ISC code and pump is the Red Hat code. In my experience people coming from Red Hat to Debian usually prefer pump because it is what they know. Note: When I'm in front of the machine, I still want to be able to use it when the network is not available (to do some local work, while waiting for the network to come back). Sure. Laptops operate that way a lot! I have a laptop and I've always had to start pump manually or invoke netenv, depending on the context. Do they use 'allow-hotplug eth0' without anything else? You say that you have always had to do that but I have never had to do that. The dhclient should start automatically. This is further information that something about your system is in an abnormal configuration. Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-06-28 15:17:45 -0600, Bob Proulx wrote: Change the 'auto eth0' line to 'allow-hotplug eth0' instead. That triggers the dhcp to happen when the device becomes available. That will probably workaround whatever problem you are experiencing. The allow-hotplug is now the default in Etch. This doesn't work. Probably a kernel problem then. I've reported the bug. How can I make pump (the DHCP client I'm using) to try again periodically? I think it should already be trying again periodically. It doesn't, even with 'allow-hotplug eth0'. Perhaps the timeout is very long. You might try dhcp3-client instead. I have had good luck with it. I had problems with it in the past and users recommended pump instead. Note: When I'm in front of the machine, I still want to be able to use it when the network is not available (to do some local work, while waiting for the network to come back). Sure. Laptops operate that way a lot! I have a laptop and I've always had to start pump manually or invoke netenv, depending on the context. Do they use 'allow-hotplug eth0' without anything else? -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
On 2007-06-29 12:50:14 +0200, Vincent Lefevre wrote: On 2007-06-28 15:17:45 -0600, Bob Proulx wrote: Change the 'auto eth0' line to 'allow-hotplug eth0' instead. That triggers the dhcp to happen when the device becomes available. That will probably workaround whatever problem you are experiencing. The allow-hotplug is now the default in Etch. This doesn't work. Probably a kernel problem then. I've reported the bug. The bug was closed, so I assume that 'allow-hotplug eth0' is a buggy answer. -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
restarting pump (DHCP) automatically when network unavailable at boot time
On a machine in a local network, I have in my /etc/network/interfaces file: auto eth0 iface eth0 inet dhcp But after a power outage, my machine sometimes restarts while the network isn't available yet. In this case, I can no longer ssh to it. And I can't reboot it remotely. How can I make pump (the DHCP client I'm using) to try again periodically? I think I can write a script that tests if pump is running (with the ps command) and can run this script by cron. But is there a better way? Note: When I'm in front of the machine, I still want to be able to use it when the network is not available (to do some local work, while waiting for the network to come back). -- Vincent Lefèvre [EMAIL PROTECTED] - Web: http://www.vinc17.org/ 100% accessible validated (X)HTML - Blog: http://www.vinc17.org/blog/ Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: restarting pump (DHCP) automatically when network unavailable at boot time
Vincent Lefevre wrote: On a machine in a local network, I have in my /etc/network/interfaces file: auto eth0 iface eth0 inet dhcp But after a power outage, my machine sometimes restarts while the network isn't available yet. That does not seem right to me. I think that with the above it should all work okay. In this case, I can no longer ssh to it. And I can't reboot it remotely. Change the 'auto eth0' line to 'allow-hotplug eth0' instead. That triggers the dhcp to happen when the device becomes available. That will probably workaround whatever problem you are experiencing. The allow-hotplug is now the default in Etch. How can I make pump (the DHCP client I'm using) to try again periodically? I think it should already be trying again periodically. Perhaps the timeout is very long. You might try dhcp3-client instead. I have had good luck with it. I am suspicious that something else is also involved here that is causing confusion as to what is really happening. Note: When I'm in front of the machine, I still want to be able to use it when the network is not available (to do some local work, while waiting for the network to come back). Sure. Laptops operate that way a lot! Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
