"ip addr show" returns interface names that won't work with "ip addr show dev <ifname>"

“ip addr show” will return a list of devices that may not work with “ip addr show dev <ifname>”.

If you have list vlan device, it will return it as “<vlan ifname>@<parent ifname>”.

However, “ip addr show dev <ifname>” will not work with that name.

“ip addr show dev <ifname>” should work with interface names that “ip addr show” returns.