Looking for a little help with OVN and creating an UPLINK

oddjobz · March 19, 2025, 9:40pm

Hmm. So … I tore down all three servers and rebuilt them without OVN.
Still had a problem with bridges (!)

Turns out Incus seems to have an issue with using addresses in the 10.0.0.0/8 range for interface IP addresses. Now this sounds completely mad, however. I switched my 10.10.10.0/24 ranges out for 192.168.2.0/24 ranges, and hey presto, my non-OVN setup worked.

I’ve now re-applied all my OVN code, and guess what - it works!

There are a couple of references online to people seeing a similar issue, here’s one;

github.com/canonical/microcloud

Failed to automatically find an unused IPv4 subnet, manual configuration required

opened 07:59AM - 10 Nov 23 UTC

closed 09:27AM - 20 Nov 23 UTC

IsaacJT

I'm trying to set up a cluster on three Orange Pi 5+'s running Ubuntu Core 22 an…d running into an issue when running `microcloud init`. ``` itrue@orangepi-2:~$ sudo microcloud init Waiting for LXD to start... Using address "10.42.0.49" for MicroCloud Limit search for other MicroCloud servers to 10.42.0.49/8? (yes/no) [default=yes]: Scanning for eligible servers ... Selected "orangepi-1" at "10.42.0.198" Selected "orangepi-3" at "10.42.0.217" Selected "orangepi-2" at "10.42.0.49" Would you like to set up local storage? (yes/no) [default=yes]: no Would you like to set up distributed storage? (yes/no) [default=yes]: Select from the available unpartitioned disks: Select which disks to wipe: Using 1 disk(s) on "orangepi-2" for remote storage pool Using 1 disk(s) on "orangepi-1" for remote storage pool Using 1 disk(s) on "orangepi-3" for remote storage pool Configure distributed networking? (yes/no) [default=yes]: Select exactly one network interface from each cluster member: Using "enP4p65s0" on "orangepi-3" for OVN uplink Using "enP4p65s0" on "orangepi-2" for OVN uplink Using "enP4p65s0" on "orangepi-1" for OVN uplink Specify the IPv4 gateway (CIDR) on the uplink network (empty to skip IPv4): 192.168.123.1/24 Specify the first IPv4 address in the range to use with LXD: 192.168.123.50 Specify the last IPv4 address in the range to use with LXD: 192.168.123.250 Specify the IPv6 gateway (CIDR) on the uplink network (empty to skip IPv6): Initializing a new cluster Local MicroCloud is ready Local LXD is ready Local MicroOVN is ready Local MicroCeph is ready Awaiting cluster formation ... Peer "orangepi-1" has joined the cluster Peer "orangepi-3" has joined the cluster Configuring cluster-wide devices ... Error: Failed generating auto config: Failed to automatically find an unused IPv4 subnet, manual configuration required ``` IP config of orangepi-1: ``` itrue@orangepi-1:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enP3p49s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:42:79 brd ff:ff:ff:ff:ff:ff inet 10.42.0.198/8 metric 100 brd 10.255.255.255 scope global dynamic enP3p49s0 valid_lft 3257sec preferred_lft 3257sec inet6 fe80::c274:2bff:feff:4279/64 scope link valid_lft forever preferred_lft forever 3: enP4p65s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:42:78 brd ff:ff:ff:ff:ff:ff inet6 fe80::c274:2bff:feff:4278/64 scope link valid_lft forever preferred_lft forever 4: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 06:32:5f:21:b9:23 brd ff:ff:ff:ff:ff:ff 5: br-int: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether e2:9c:1c:8e:01:f6 brd ff:ff:ff:ff:ff:ff 6: genev_sys_6081: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000 qdisc noqueue master ovs-system state UNKNOWN group default qlen 1000 link/ether b6:0b:69:70:56:3c brd ff:ff:ff:ff:ff:ff inet6 fe80::449b:58ff:fe55:45c7/64 scope link valid_lft forever preferred_lft forever itrue@orangepi-1:~$ ip r default via 10.42.0.1 dev enP3p49s0 proto dhcp src 10.42.0.198 metric 100 10.0.0.0/8 dev enP3p49s0 proto kernel scope link src 10.42.0.198 metric 100 10.42.0.1 dev enP3p49s0 proto dhcp scope link src 10.42.0.198 metric 100 ``` IP config of orangepi-2: ``` itrue@orangepi-2:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enP3p49s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:3a:db brd ff:ff:ff:ff:ff:ff inet 10.42.0.49/8 metric 100 brd 10.255.255.255 scope global dynamic enP3p49s0 valid_lft 3215sec preferred_lft 3215sec inet6 fe80::c274:2bff:feff:3adb/64 scope link valid_lft forever preferred_lft forever 3: enP4p65s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:3a:da brd ff:ff:ff:ff:ff:ff inet6 fe80::c274:2bff:feff:3ada/64 scope link valid_lft forever preferred_lft forever 4: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether de:05:47:8d:c7:27 brd ff:ff:ff:ff:ff:ff 5: br-int: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether be:e1:a1:a0:74:b1 brd ff:ff:ff:ff:ff:ff 6: genev_sys_6081: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000 qdisc noqueue master ovs-system state UNKNOWN group default qlen 1000 link/ether ce:13:87:ac:76:8b brd ff:ff:ff:ff:ff:ff inet6 fe80::9842:c4ff:feb9:bd76/64 scope link valid_lft forever preferred_lft forever itrue@orangepi-2:~$ ip r default via 10.42.0.1 dev enP3p49s0 proto dhcp src 10.42.0.49 metric 100 10.0.0.0/8 dev enP3p49s0 proto kernel scope link src 10.42.0.49 metric 100 10.42.0.1 dev enP3p49s0 proto dhcp scope link src 10.42.0.49 metric 100 ``` IP config of orangepi-3: ``` itrue@orangepi-3:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enP3p49s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:39:51 brd ff:ff:ff:ff:ff:ff inet 10.42.0.217/8 metric 100 brd 10.255.255.255 scope global dynamic enP3p49s0 valid_lft 3238sec preferred_lft 3238sec inet6 fe80::c274:2bff:feff:3951/64 scope link valid_lft forever preferred_lft forever 3: enP4p65s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether c0:74:2b:ff:39:50 brd ff:ff:ff:ff:ff:ff inet6 fe80::c274:2bff:feff:3950/64 scope link valid_lft forever preferred_lft forever 4: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 22:8f:3a:9c:78:6b brd ff:ff:ff:ff:ff:ff 5: br-int: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 2a:30:d1:71:c0:23 brd ff:ff:ff:ff:ff:ff 6: genev_sys_6081: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000 qdisc noqueue master ovs-system state UNKNOWN group default qlen 1000 link/ether 72:e0:09:9a:0a:01 brd ff:ff:ff:ff:ff:ff inet6 fe80::9ca0:f5ff:fed8:2fcb/64 scope link valid_lft forever preferred_lft forever itrue@orangepi-3:~$ ip r default via 10.42.0.1 dev enP3p49s0 proto dhcp src 10.42.0.217 metric 100 10.0.0.0/8 dev enP3p49s0 proto kernel scope link src 10.42.0.217 metric 100 10.42.0.1 dev enP3p49s0 proto dhcp scope link src 10.42.0.217 metric 100 ```

Note the error quoted here is the one I was experiencing when trying to create an OVN network. Now I’m a little bit speechless and somewhat embarrassed to post this, because it can’t be right that the issue is actually the non-routed address range chosen … and I will update it if I actually find I did something else wrong, but for now, as far as I can see, switching 10.10.10.0/24 for 192.168.2.0/24 fixed the problem. (My OVN/Incus deployment is mostly automated, so I’m reasonably confident this is the only change)