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GUADEC PSA: WiFi fails due to dhclient lease miscalculation

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http://blogs.gnome.org – The DHCP server at GUADEC apparently gives out infinite leases, which have a value of 0xFFFFFFFF (in seconds).  Leaving aside the question of whether infinite leases are actually a good idea at a conference where many people come and go (hint: they usually aren’t),  why won’t it just @#%@#%!&&* connect? By default NetworkManager uses dhclient for DHCP, and that usually works fairly well.  It’s a well-understood program developed by the ISC that’s used by millions every day.  But dhclient apparently fails with infinite leases.  Here’s the dhclient code (General)

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Submitted by hwq123 on 07/25/2012 – Made popular on 07/25/2012

Stories similar to GUADEC PSA: WiFi fails due to dhclient lease miscalculation

I use dhcp in /etc/network/interfaces: auto eth0 iface eth0 inet dhcp No network-manager installed.

This makes the dhclient run with option "-1":dhclient3 -e IF_METRIC=100 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0 dhclient manpage: The -1 flag will cause dhclient to try once to get a lease.

I have a Lucid 64bit server implementation. I appear to have two versions of dhclient3 running at all times as shown below. I wonder whether this is normal and if not if there is a solution to fix? As can be seen both instances are attached to the same interface i.e.

I need to retrieve the DHCP option 130 from my DHCP server on a Windows 2008 server.

I managed to get it on linux with the following config :

/etc/dhcp/dhclient-eth0.conf :

option my-custom-option code 130 = text; request subnet-mask, broadcast-address, time-offset, routers, domain-name, domain-name-servers, host-name, my-custom-option;

Then in /var/lib/dhclient/dhclient-eth0.leases :

lease

We have a subnet with a couple of hundred virtual machines that:

boot up do some short heavy computational task and shut down.

The average life of a vm here is about 20 minutes.

Calling dhclient as root works beautifully on my debian machine. However, I would like to allow some users to execute dhclient, too.

What I'm trying to achieve is to get cold-start, zero-state DHCP lease which means forcing dhclient through the full discovery and configuration process (DHCPDISCOVER–DHCPOFFER–DHCPREQUEST–DHCPACK as opposed to the shortcutted DHCPREQUEST–DHCPACK cycle which uses a remembered address).

Hi everybody,

I'm using Ubuntu 9.10.

I've got no problems with my WLAN, but sometimes after awaking from suspend-to-ram, which was triggered by the command:

wlan0 down/up repeatedly 43 weeks 6 days ago

I keep having wlan0 dropping and reconnecting due to loss of IPv6 address.

Code: Jul 21 22:23:51 Lenovo avahi-daemon[849]: Withdrawing address record for fe80::120b:a9ff:fec7:2a7c on wlan0. Jul 21 22:23:51 Lenovo dhclient[7463]: Internet Systems Consortium DHCP Client 4.2.4 Jul 21 22:23:51 Lenovo dhclient[7463]: Copyright 2004-2012 Internet Systems Consortium. Jul 21 22:23:51 Lenovo dhc

I am doing a "dhclient" on one of the network interface which is in UP state. There is no DHCP server running in the network on which this node is present.