Intel 10Gbe interface (ix driver) cannot link at 1Gb/s to a switch IF any vlan on that interface is enabled. With no vlan enabled it connects fine.
Temporary workaround is to delay creating vlans until link is up.
FreeBSD puchar.net 11.1-PRERELEASE FreeBSD 11.1-PRERELEASE #5: Sat Aug 12 10:51:41 CEST 2017 email@example.com:/usr/src/sys/amd64/compile/puchar amd64
ix0: <Intel(R) PRO/10GbE PCI-Express Network Driver, Version - 3.2.12-k> port 0xe020-0xe03f mem 0xfbc00000-0xfbdfffff,0xfbe04000-0xfbe07fff irq 42 at device 0.0 on pci4
ix0: Using MSI-X interrupts with 9 vectors
ix0: Ethernet address: 0c:c4:7a:6e:7e:9e
ix0: PCI Express Bus: Speed 5.0GT/s Width x8
We need more info:
1. Output of pciconf -lv
2. Contents of /etc/rc.conf
3. Contents of /boot/loader.conf
4. Switch model being used
5. Media type being used
Created attachment 185491 [details]
Created attachment 185492 [details]
Created attachment 185493 [details]
rc.conf - read comment
with vlan it includes vlan0 in cloned interfaces, addm vlan0 in bridge0 and
ifconfig_vlan0="vlan 1157 vlandev ix0 up"
as for switch type i wait for response - not my switch, i'm not physically close to the machine.
switch is Extreme x450a-48T, latest firmware. port is set up to force gigabit.
Forced speed often causes issues just set it to auto