Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Description of problem:
After the upgrade the system from RHEL 8.1 4.18.0-147 to RHEL 8.2 4.18.0-193 or 4.18.0-222.el8.s390x, the NetworkManager can not get a DHCP Address for the interface.
If we configure the file "/etc/NetworkManager/NetworkManager.conf" with the parameter dhcp=dhclient under the key [main]:
# cat /etc/NetworkManager/NetworkManager.conf
[main]
dhcp=dhclient
When we set NetworkManager to use dhclient the server can configure the IPV4 on the interface.
Also, if we use the network.service instead of NetworkManager the server will configure the IPv4 address in the interface normally.
The issue only reproduce using NetworkManager.
Version-Release number of selected component (if applicable):
First scenario that the problem occurred:
RHEL 8.2 4.18.0-193.1.2.el8_2.s390x
NetworkManager-1.22.8-4.el8.s390x Wed Jun 24 11:59:56 2020
NetworkManager-libnm-1.22.8-4.el8.s390x Wed Jun 24 11:59:56 2020
NetworkManager-team-1.22.8-4.el8.s390x Wed Jun 24 12:00:15 2020
NetworkManager-tui-1.22.8-4.el8.s390x Wed Jun 24 12:00:16 2020
dracut-network-049-70.git20200228.el8.s390x Wed Jun 24 12:00:07 2020
network-scripts-10.00.6-1.el8.s390x Wed Jun 24 11:59:48 2020
network-scripts-team-1.29-1.el8.s390x Wed Jun 24 12:00:00 2020
Second scenario that the problem occurred:
RHEL 8 devel kernel 4.18.0-222.el8.s390x
NetworkManager-1.22.8-5.el8_2.s390x Wed Jul 15 08:28:32 2020
NetworkManager-config-server-1.22.8-5.el8_2.noarch Wed Jul 15 08:28:32 2020
NetworkManager-libnm-1.22.8-5.el8_2.s390x Wed Jul 15 08:28:31 2020
NetworkManager-team-1.22.8-5.el8_2.s390x Wed Jul 15 08:28:32 2020
NetworkManager-tui-1.22.8-5.el8_2.s390x Wed Jul 15 08:28:32 2020
dracut-network-049-70.git20200228.el8.s390x Tue Jun 30 13:16:14 2020
network-scripts-10.00.6-1.el8.s390x Tue Jun 30 13:15:53 2020
network-scripts-team-1.29-1.el8.s390x Tue Jun 30 13:16:05 2020
How reproducible:
Upgrade the RHEL 8.1 4.18.0-147.5.1.el8_1.s390x to RHEL 8.2 4.18.0-193.1.2.el8_2.s390x or later
Steps to Reproduce:
1. Upgrade the RHEL 8.1 4.18.0-147.5.1.el8_1.s390x to RHEL 8.2 4.18.0-193.1.2.el8_2.s390x or later
2. Reboot the system
3. The server will start and won't get a DHCP Address
Actual results:
The customer is work around the using:
# cat /etc/NetworkManager/NetworkManager.conf
[main]
dhcp=dhclient
Expected results:
As the network.service will be deprecated the customer expect to get a DHCP using NetworkManager.
Additional info:
In the beginning we think that this was the same issue as in BZ 1843357 - NetworkManager doesn't reconnect after DHCP failure [rhel-8.2.0.z]. But is not, this is a different issue.
Attach in this BZ the "/var/log/messages" and "/var/log/dmesg" file from the server.
in the SOS report at https://access.redhat.com/support/cases/#/case/02682336?attachmentId=a092K000025It8IQAS , in file [1] we see how the internal/nettools DHCP client is used.
We see that the client repeatedly sends
dhcp4 (enc350): send DISCOVER to 255.255.255.255
without reply.
[1] ./sos_commands/logs/journalctl_--no-pager_--catalog_--boot
From the provided information, it cannot be seen why it wouldn't work.
Please capture a package trace, with tcpdump. You don't need to reboot, just start run tcpdump while reactivating the profile (and wait long enough, to see whether there are any responses).
tcpdump -s 0 -i any -w /tmp/my-capture.pcap
Since the difference is apparently the DHCP implementation, it would be most helpful to retry this also with the dhclient plugin.
Btw, the dhclient plugin is still fully supported. So, it is a reasonable workaround to use dhcp=dhclient in this case.
(In reply to Thomas Haller from comment #3)
> in the SOS report at
> https://access.redhat.com/support/cases/#/case/
> 02682336?attachmentId=a092K000025It8IQAS , in file [1] we see how the
> internal/nettools DHCP client is used.
>
> We see that the client repeatedly sends
>
> dhcp4 (enc350): send DISCOVER to 255.255.255.255
>
> without reply.
>
> [1] ./sos_commands/logs/journalctl_--no-pager_--catalog_--boot
>
>
>
> From the provided information, it cannot be seen why it wouldn't work.
>
> Please capture a package trace, with tcpdump. You don't need to reboot, just
> start run tcpdump while reactivating the profile (and wait long enough, to
> see whether there are any responses).
>
> tcpdump -s 0 -i any -w /tmp/my-capture.pcap
>
>
>
> Since the difference is apparently the DHCP implementation, it would be most
> helpful to retry this also with the dhclient plugin.
>
>
>
> Btw, the dhclient plugin is still fully supported. So, it is a reasonable
> workaround to use dhcp=dhclient in this case.
Hi I'm attaching the captures in the BZ.
Thanks Thiago.
The package trace shows that the server sends DHCP offers. By looking at the capture, I don't see anything wrong with it, which would cause the DHCP client to reject the packets. I'll ask Beniamino for his opinion.
You already established that dhclient works. Did you ever test `dhcp=systemd` plugin in that environment? Does that implementation work? That would be interesting to know, to have some comparison.
Comment 7Beniamino Galvani
2020-08-03 18:35:36 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (NetworkManager bug fix and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2020:4499