ubuntu 18.04: not releasing old IPs from DHCP

We're running ubuntu 18.04, with the following configuration of netplan:

network:

  version: 2

  renderer: networkd

  ethernets:

    ens3:

      dhcp4: yes

Currently we're running into an issue with DHCP, seems old IPs are not being freed after assigning a new one:

2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000

    link/ether 00:1a:4a:X:Y:Z brd ff:ff:ff:ff:ff:ff

    inet 10.X.Y.175/23 brd 10.X.Y.255 scope global ens3

       valid_lft forever preferred_lft forever

    inet 10.X.Y.201/23 brd 10.X.Y.255 scope global secondary dynamic ens3

       valid_lft 3136sec preferred_lft 3136sec

    inet 10.X.Y.168/23 brd 10.X.Y.255 scope global secondary ens3

       valid_lft forever preferred_lft forever

    inet6 fe80::21a:4aff:fe97:5f31/64 scope link 

       valid_lft forever preferred_lft forever

This is generating duplicated IP addresses as some IPs are being reused but not freed, generating to the users a lot of issues.

What is causing this behavior and how can it be solved?

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

This is happening only on Ubuntu 18.04. We have thousands of VMs with other OSs like Ubuntu 14.04, CentOS, RedHat and it won't happen here.

– nKn
Oct 10 '18 at 13:13

add a comment |

We're running ubuntu 18.04, with the following configuration of netplan:

network:

  version: 2

  renderer: networkd

  ethernets:

    ens3:

      dhcp4: yes

Currently we're running into an issue with DHCP, seems old IPs are not being freed after assigning a new one:

2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000

    link/ether 00:1a:4a:X:Y:Z brd ff:ff:ff:ff:ff:ff

    inet 10.X.Y.175/23 brd 10.X.Y.255 scope global ens3

       valid_lft forever preferred_lft forever

    inet 10.X.Y.201/23 brd 10.X.Y.255 scope global secondary dynamic ens3

       valid_lft 3136sec preferred_lft 3136sec

    inet 10.X.Y.168/23 brd 10.X.Y.255 scope global secondary ens3

       valid_lft forever preferred_lft forever

    inet6 fe80::21a:4aff:fe97:5f31/64 scope link 

       valid_lft forever preferred_lft forever

This is generating duplicated IP addresses as some IPs are being reused but not freed, generating to the users a lot of issues.

What is causing this behavior and how can it be solved?

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

This is happening only on Ubuntu 18.04. We have thousands of VMs with other OSs like Ubuntu 14.04, CentOS, RedHat and it won't happen here.

– nKn
Oct 10 '18 at 13:13

add a comment |

We're running ubuntu 18.04, with the following configuration of netplan:

network:

  version: 2

  renderer: networkd

  ethernets:

    ens3:

      dhcp4: yes

Currently we're running into an issue with DHCP, seems old IPs are not being freed after assigning a new one:

2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000

    link/ether 00:1a:4a:X:Y:Z brd ff:ff:ff:ff:ff:ff

    inet 10.X.Y.175/23 brd 10.X.Y.255 scope global ens3

       valid_lft forever preferred_lft forever

    inet 10.X.Y.201/23 brd 10.X.Y.255 scope global secondary dynamic ens3

       valid_lft 3136sec preferred_lft 3136sec

    inet 10.X.Y.168/23 brd 10.X.Y.255 scope global secondary ens3

       valid_lft forever preferred_lft forever

    inet6 fe80::21a:4aff:fe97:5f31/64 scope link 

       valid_lft forever preferred_lft forever

This is generating duplicated IP addresses as some IPs are being reused but not freed, generating to the users a lot of issues.

What is causing this behavior and how can it be solved?

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

We're running ubuntu 18.04, with the following configuration of netplan:

network:

  version: 2

  renderer: networkd

  ethernets:

    ens3:

      dhcp4: yes

Currently we're running into an issue with DHCP, seems old IPs are not being freed after assigning a new one:

2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000

    link/ether 00:1a:4a:X:Y:Z brd ff:ff:ff:ff:ff:ff

    inet 10.X.Y.175/23 brd 10.X.Y.255 scope global ens3

       valid_lft forever preferred_lft forever

    inet 10.X.Y.201/23 brd 10.X.Y.255 scope global secondary dynamic ens3

       valid_lft 3136sec preferred_lft 3136sec

    inet 10.X.Y.168/23 brd 10.X.Y.255 scope global secondary ens3

       valid_lft forever preferred_lft forever

    inet6 fe80::21a:4aff:fe97:5f31/64 scope link 

       valid_lft forever preferred_lft forever

This is generating duplicated IP addresses as some IPs are being reused but not freed, generating to the users a lot of issues.

What is causing this behavior and how can it be solved?

networking 18.04 dhcp netplan

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

edited Oct 10 '18 at 13:37

asked Oct 10 '18 at 12:56

nKn

1163

asked Oct 10 '18 at 12:56

nKn

1163

asked Oct 10 '18 at 12:56

nKn

1163

This is happening only on Ubuntu 18.04. We have thousands of VMs with other OSs like Ubuntu 14.04, CentOS, RedHat and it won't happen here.

– nKn
Oct 10 '18 at 13:13

add a comment |

This is happening only on Ubuntu 18.04. We have thousands of VMs with other OSs like Ubuntu 14.04, CentOS, RedHat and it won't happen here.

– nKn
Oct 10 '18 at 13:13

This is happening only on Ubuntu 18.04. We have thousands of VMs with other OSs like Ubuntu 14.04, CentOS, RedHat and it won't happen here.

– nKn
Oct 10 '18 at 13:13

add a comment |

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