On Sat, Nov 16, 2019 at 7:05 PM Sam Varshavchik <mrsam(a)courier-mta.com> wrote:
I have a fixed IP address assigned via DHCP to a machine that I
just updated to F31.
After the update, I was slightly surprised when it didn't come up
on its fixed IP address. After looking through the logs, the DHCP
server is now apparently getting a DHCP request from a different
MAC address, apparently the bridge's MAC address. I updated the
DHCP config, and brought the network connection down/up, and it
came up on its fixed IP address, normally.
In F30, the kernel was kernel-5.3.11-200.fc30.x86_64, and it's now
kernel-5.3.11-300.fc31.x86_64, of course; so this doesn't look like
a kernel change.
The relevant data is:
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master
vnet0 state UP group default qlen 1000
link/ether 00:30:48:fc:83:fa brd ff:ff:ff:ff:ff:ff
inet6 fe80::230:48ff:fefc:83fa/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default
qlen 1000
link/ether 00:30:48:fc:83:fb brd ff:ff:ff:ff:ff:ff
4: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
link/ether 96:03:13:50:00:eb brd ff:ff:ff:ff:ff:ff
inet 192.168.0.2/24 brd 192.168.0.255 scope global dynamic vnet0
valid_lft 603710sec preferred_lft 603710sec
inet6 fe80::9403:13ff:fe50:eb/64 scope link
valid_lft forever preferred_lft forever
Up until F30, the DHCP server was seeing requests from
00:30:48:fc:83:fa, and now the DHCP server is seeing requests from
96:03:13:50:00:eb.
I'm hoping that, at least, the bridge won't be getting random MAC
addresses with every boot?
There was a thread here earlier this month about having to set the
bridge MAC address with "MACADDRESS=mac_address_of_eth0" to ensure
that vnet0 inherits the same MAC address of its first slave.
This must be an NM issue because ip behaves "normally":
# ip l sh dev wlo1 | g ether
link/ether 18:56:80:7e:d3:da brd ff:ff:ff:ff:ff:ff
# ip l add dummy0 type dummy
# ip l sh dev dummy0 | g ether
link/ether ea:e4:fb:6f:97:b1 brd ff:ff:ff:ff:ff:ff
# ip l add bridge0 type bridge
# ip l sh dev bridge0 | g ether
link/ether fa:1b:c7:58:5a:b3 brd ff:ff:ff:ff:ff:ff
# ip l set dev dummy0 master bridge0
# ip l sh dev bridge0 | g ether
link/ether ea:e4:fb:6f:97:b1 brd ff:ff:ff:ff:ff:ff
#
networkd had the same problem as NM but it's apparently been fixed
https://github.com/systemd/systemd/issues/12558