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mouseman

Member

From: Outta nowhere

Registered: 2014-04-04

Posts: 291

ovs vswitch br-iface no dhcp / eno1 not up

Edit: part of this is resolved, see post #2.
Edit 2: I've abandonded open vswitch, even in a simple configuration it was too slow before new interfaces came up and when destroying kvm guests, the network would go down temporarily.
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I am configuring open vswitch and while it generally is working and doing what I want, I am running into the issue that the ovs interfaces I create, seem to advertise a different mac address than what is shown with nmcli dev show int and ip addr. Moreover, on each restart this seems to change while the displayed mac stays the same.  Therefore I cannot configure fixed IP leases based on mac address.

Example, current lease my dhcp server handed out:

10.0.0.167 	fe:69:94:af:3f:59 		hostname01 		2020/08/23 08:51:13 	2020/08/23 10:51:13 	online 	active

Output from ip address:

32: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 3e:62:86:8c:d9:c8 brd ff:ff:ff:ff:ff:ff
35: ovs-int-p0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether 6a:01:64:65:84:d3 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.167/24 brd 10.26.14.255 scope global dynamic noprefixroute ovs-int-p0
       valid_lft 6886sec preferred_lft 6886sec
    inet6 fe80::2edd:f2be:dd42:490f/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

When I look at the device with nmcli dev show iface0:

GENERAL.DEVICE:                         iface0
GENERAL.TYPE:                           ovs-interface
GENERAL.HWADDR:                         6A:01:64:65:84:D3

There I see the address matches what ip addr shows.

When I issue nmcli con down iface0 && nmcli con up iface0, the mac address that is shown with nmcli and ip addr stays the same, but on my dhcp server I see a new one (and obviously, a new ip address as well):

10.0.0.168 	1e:5f:36:e7:6f:d7 		hostname01 		2020/08/23 09:02:48 	2020/08/23 11:02:48 	online 	active

Any ideas how I can fix this? The alternative is that I set fixed ip addresses but that is cumbersome with many hosts. My dhcp server hands out dns and ntp servers, domain suffixes etc.

Thanks in advance!

Last edited by mouseman (2020-08-26 05:58:41)

mouseman

Member

From: Outta nowhere

Registered: 2014-04-04

Posts: 291

Re: ovs vswitch br-iface no dhcp / eno1 not up

oke, fixed part of the issue.

The issue is that Network Manager deletes and recreates the ports and interfaces with nmcli con down / up, so they get new mac addresses. So:

pacman -Rcn networkmanager

.

Create the ovs bridge and ports with ovs-vsctl and set the mac address:

# ovs-vsctl set interface iface-name mac="ef:fe:be:ff:e1:01"

Without network manager I needed another way to get an ip address for the bridge interface. So:

systemctl enable --now dhclient@iface-name.service

This worked, except after a reboot it failed and wouldn't grab an ip address, not even manually with dhclient -i iface-name. I need to manually set eno1 up with ip link and restart dhclient.

Anyone any ideas why eno1 won't come up automatically and how i can fix that?

Last edited by mouseman (2020-08-23 16:46:16)

rsmarples

Member

Registered: 2009-05-12

Posts: 287

Re: ovs vswitch br-iface no dhcp / eno1 not up

I dont think dhclient brings up interfaces by itself - the service file will have to. dhcpcd will as well, if you want another possible solution.