Re: dhcpcd timeout

[Victor Gaydov <victor gaydov gmail com>]

On Tue, 22 Jun 2010 17:25:32 -0700
Dan Williams <dcbw redhat com> wrote:

> On Tue, 2010-06-22 at 17:39 +0400, Victor Gaydov wrote:
> > On Tue, 22 Jun 2010 01:21:29 -0700
> > Dan Williams <dcbw redhat com> wrote:
> > 
> > > On Fri, 2010-06-11 at 12:42 +0400, Victor Gaydov wrote:
> > > > On Fri, 04 Jun 2010 19:23:55 -0700
> > > > Dan Williams <dcbw redhat com> wrote:
> > > > 
> > > > > On Thu, 2010-06-03 at 10:34 +0400, Victor Gaydov wrote:
> > > > > > Hello,
> > > > > > 
> > > > > > After upgrade from 0.7 to 0.8 NetworkManager compiled with
> > > > > > dhcpcd can't start connection because of dhcpcd timeout. Is
> > > > > > it a way to change this timeout?
> > > > > > 
> > > > > > Notes:
> > > > > >  - NetworkManager compiled with dhclient works fine
> > > > > >  - dhcpcd executed manually work fine
> > > > > >  - it seems that lease-time from /etc/dhcp/dhcpd.conf
> > > > > > doesn't matter when dhcpcd is executed by NM
> > > > > > 
> > > > > > Log attached.
> > > > > 
> > > > > Is there any chance you could run wireshark on the interface
> > > > > and see if any DHCP packets get out?  This is quite odd and
> > > > > it would point to either a misconfiguraton of dhcpcd on NM's
> > > > > part (maybe sendign the wrong command-line arguments) or it
> > > > > could point to a problem in dhcpcd.  It might also be useful
> > > > > to strace dhcpcd to see what it's doing.
> > > > > 
> > > > > The logs show the problem, but don't really provide any
> > > > > insight into what might be going on.  The other alternative
> > > > > may be to recompile NM and send any debugging or verbose
> > > > > command-line arguments that dhcpcd might use to get more
> > > > > output from it about the issue.
> > > > > 
> > > > > Dan
> > > > > 
> > > > > 
> > > > 
> > > > Hello! Sorry for delay.
> > > > 
> > > > The problem was related to timeouts: 45s is not enough. I
> > > > changed DHCP_TIMEOUT in sources and added '-t' option to dhcpcd
> > > > and everything works fine. Is it a way to change dhcp timeout
> > > > in config file?
> > > > 
> > > > PS. Debug log is attached. I can also send wireshark log if
> > > > necessary - yes, DHCP packets are getting out.
> > > 
> > > So in this case the server is just very, very slow to respond?
> > > Is the network heavily loaded?  Or is the DHCP server heavily
> > > loaded?  I'm not really opposed to upping the timeout by a small
> > > amount, but if the DHCP server isn't responding within a certain
> > > timeframe, there's clearly something wrong with the network,
> > > whether that timeframe is 45 seconds, 60 seconds, or whatever.
> > > At this point, upping the timeout isn't really guaranteed to fix
> > > the problem anyway if it's this bad already...
> > > 
> > > What DHCP timeout worked for you?
> > > 
> > > Dan
> > > 
> > > 
> > > 
> > 
> > Timeout varies from 30 seconds to a minute. It is desktop computer
> > and ADSL modem; provider is "stream" (http://www.stream.ru).
> > Dhclient sends a few (about 3 of 4) queries before server responds.
> > 
> > I can provide any details, if necessary, but in any case I'm not
> > able to configure anything except client side. I think
> > NetworkManager's restrictions looks quite artificial: yes, it may
> > be something wrong with network, but it's more flexible to allow
> > user to configure it by himself.. Anyway, NM compiled with dhclient
> > works fine, so there are no problems for me.
> 
> So dhclient works fine with the default 45 second timeout, but dhcpcd
> does *not* work with the 45 second timeout?
> 
> Dan
> 

After some testing, no, dhclient also sometimes doesn't work. But for
some reason dhcpcd fails more often than dhclient.

-- 
Victor Gaydov.