Re: DHCP lease renew

[Thomas Haller <thaller redhat com>]

On Mon, 2018-12-24 at 13:43 +0000, Usyskin, Alexander wrote:
> > -----Original Message-----
> > From: Thomas Haller [mailto:thaller redhat com]
> > Sent: Monday, December 24, 2018 11:35
> > To: Usyskin, Alexander <alexander usyskin intel com>;
> > networkmanager-
> > list gnome org
> > Subject: Re: DHCP lease renew
> >
> > On Mon, 2018-12-24 at 08:03 +0000, Usyskin, Alexander via
> > networkmanager-
> > list wrote:
> > > Hi
> > >
> > > I'm trying to force DHCP lease renew for specific interface.
> > > Basically replicate in Linux IpRenewAddress function from Win32
> > > API.
> > > Without NetworkManager it's fairly simple, like "dhclient -r eth4
> > > &&
> > > dhclient -1 eth4".
> > > But NetworkManager manages dhclient in different way, so that
> > > lead to
> > > an unexpected consequences.
> > >
> > > I can't find a way to ask NetworkManager to forcefully renew the
> > > lease. Neither through DBus API, nor from command line.
> > > Is there any way to do such thing?
> > > If not, how can I file an enhancement request?
> > >
> > > Please CC me on reply, I'm not subscribed to this list.
> > Hi,
> >
> >
> > $ nmcli device reapply $IFNAME
> >
> > (or, on D-Bus, via Device's Reapply() method).
> >
> >
> > (or, fully reactivate the profile, like)
> >
> >   nmcli connection up "$PROFILE"
> >
> >
> > best,
> > Thomas
>
> Tried to run reapply (via DBus call, but also tried nmcli), have 
> "NetworkManager[916]: <info>  [1545650569.2423] audit: op="device-
> reapply" interface="eth4" ifindex=2 pid=28554 uid=0 result="success"
> "
> in syslog, but no DHCP activity observed on the link.
>
> What I'm doing wrong here?
>
> For the record it's Ubuntu 16.04 LTS with nm version 1.2.6
>
> Thanks


Hi,


ah right. Reapply() doesn't restart DHCP. Sorry.

I guess, that leaves you with:

- a full reactivation, like
  nmcli connection up "$PROFILE"

- disable and re-enable DHCP:

  nmlic device modifiy "$IFACE" ipv4.method disabled
  nmlic device modifiy "$IFACE" ipv4.method auto

  This also uses Reapply() D-Bus method under the hood.
  However, I don't know whether that works with 1.2.6, which is
  2 years old.


Maybe you could explain, why you want to request a new lease?


best,
Thomas

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