How do I solve this log warning, "br0: failed to renew DHCP, rebinding"?


Recommended Posts

My understanding is that when a DHCP lease has half its life to run the client requests a renewal of the lease in the expectation of it being granted (so it gets to keep the same IP address for another lease duration). If it receives no reply from the server the client waits for another half-life and then repeats the request. If the requests are repeatedly ignored then in order to stay active on the network the client at some point has to give up the lease and solicit a new one from any available server. On a complex network with multiple DHCP servers that's likely to result is a change of IP address for the client, but on a simple network with only one DHCP server that has stopped granting renewal requests that request to rebind is also likely to be ignored. Maybe your DHCP server has crashed, so the first thing I'd try is rebooting the DHCP server. There is a case where there's a great demand for leases but only a small pool of IP addresses and none of them reserved for your particular MAC address that could lead to the pool being exhausted but you'd probably be aware of it if that applies in your case.

Link to comment
  • 1 month later...
  • 2 weeks later...

First of all I want to say that I did not see any services malfunctioning and my server still has its expected IP, but

I saw the same message as above for the first time in my Log today.

 

Jul 29 16:06:59 Morpheus dhcpcd[2004]: br0: failed to renew DHCP, rebinding
Jul 29 16:06:59 Morpheus dnsmasq[10854]: reading /etc/resolv.conf
Jul 29 16:06:59 Morpheus dnsmasq[10854]: using nameserver 1.1.1.1#53
Jul 29 16:06:59 Morpheus dnsmasq[10854]: using nameserver 1.0.0.1#53

 

I was just upgrading my networking gear to unify (USG, Switch-8-150W and UAP-ACC Lite) last week, and am now wondering if I missconfigured something.

Can anyone shed some light on the meaning of the logentries for me ?

Link to comment
  • 4 weeks later...
On 7/29/2019 at 6:50 PM, Kevek79 said:

Can anyone shed some light on the meaning of the logentries for me ?

The first one is explained above. After rebinding, Morpheus potentially has a new IP address and therefore potentially a whole new network configuration. So it might need to use different name servers for DNS resolution - DHCP servers usually offer recommended DNS servers along with IP addresses but you seem to have manually over-ridden that automatic allocation of DNS servers, so the second message shows Morpheus reading the resolver configuration file and the remaning two messages show that nameservers 1.1.1.1 and 1.0.0.1 have been chosen.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.