pfSense

I think it is saying the error occurred on this line in interface_bring_down:

if (!isset($config['interfaces'][$interface]))

Maybe the caller is giving it bad data, like a blank string for the interface name.

Well, now the error does not occur. But now at change of type virtual IP the previous is not deleted.

I have replaced type from IF alias to ProxyARP and have received at once 2 virtual addresses simultaneously:

# ifconfig em0
em0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
    ether 00:30:48:8b:4f:2c
    inet6 fe80::230:48ff:fe8b:4f2c%em0 prefixlen 64 scopeid 0x2 
    inet 192.168.168.2 netmask 0xffffff00 broadcast 192.168.168.255
->>> inet 192.168.168.3 netmask 0xffffffff broadcast 192.168.168.3
    nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active

# ps auxw |grep choparp
root   24758  0.0  0.0  3316  1008  ??  Is    2:06PM   0:00.00 /usr/local/sbin/choparp em0 auto 192.168.168.3/32

...and if again to change back, are deleted all IP addresses from the interface, except the virtual. Even the main IP:

# ifconfig em0  
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
    ether 00:30:48:8b:4f:2c
    inet6 fe80::230:48ff:fe8b:4f2c%em0 prefixlen 64 scopeid 0x2 
    inet 192.168.168.3 netmask 0xffffffff broadcast 192.168.168.3
    nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active

192.168.192.1/24 - Main IP
192.168.168.2/24 - virtual IP (1)
192.168.168.3/32 - virtual IP (2) - changed

Applied in changeset e03b0a03fb52f94e4f2a85baecdcb9ada18ec939.

if (preg_match("/^vip/^tun|^ovpn|^gif|^gre|^lagg|^bridge|vlan/i", $realif))
                     ^
                     ^-- error can here?

I have tested again.

Now Virtual IP (IfAlias) on the interface correctly is added and deleted.
But at change from ProxyARP to IfAlias, choparp remains running.

# ps auxww|grep choparp
root   57326  0.0  0.0  3316  1024  ??  Ss    9:43AM   0:00.01 /usr/local/sbin/choparp em0 auto 192.168.168.3/32

Now with one virtual IP really works.

But :)
If to change at once 2 virtual IP (and more)..

Before tests (VIP: 192.168.168.3/32, 192.168.168.4/32)

em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
    inet 192.168.192.1 netmask 0xffffff00 broadcast 192.168.192.255
    inet 192.168.168.2 netmask 0xffffff00 broadcast 192.168.168.255
    inet 192.168.168.3 netmask 0xffffffff broadcast 192.168.168.3
    inet 192.168.168.4 netmask 0xffffffff broadcast 192.168.168.4

• Change from If to ARP.
  • IfAliases were deleted before I have pressed the button 'Apply changes'
    

    em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
        inet 192.168.192.1 netmask 0xffffff00 broadcast 192.168.192.255
        inet 192.168.168.2 netmask 0xffffff00 broadcast 192.168.168.255
    

  • After button 'Apply changes' pressing, there were 2 processes choparp, both with identical IP.
    

    root   36529  0.0  0.0  3316  1052  ??  Ss   11:13AM   0:00.00 /usr/local/sbin/choparp em0 auto 192.168.168.4/32
    root   36693  0.0  0.0  3316  1052  ??  Ss   11:13AM   0:00.00 /usr/local/sbin/choparp em0 auto 192.168.168.4/32
    

• Change back from ARP to If.
  • Again changes have occurred before button 'Apply changes' pressing. One process 'choparp' was deleted and one remained.
    

    root   36529  0.0  0.0  3316  1052  ??  Ss   11:13AM   0:00.01 /usr/local/sbin/choparp em0 auto 192.168.168.4/32
    

  • After button 'Apply changes' pressing, one process 'choparp' still remained, but IfAliases have normally formed.
    

    em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
        inet 192.168.192.1 netmask 0xffffff00 broadcast 192.168.192.255
        inet 192.168.168.2 netmask 0xffffff00 broadcast 192.168.168.255
        inet 192.168.168.3 netmask 0xffffffff broadcast 192.168.168.3
        inet 192.168.168.4 netmask 0xffffffff broadcast 192.168.168.4
    --------
    root   36529  0.0  0.0  3316  1052  ??  Ss   11:13AM   0:00.01 /usr/local/sbin/choparp em0 auto 192.168.168.4/32
    root   51330  0.0  0.0  3524  1240   0  S+   11:26AM   0:00.00 grep arp
    
    

Well the problem with changing the type of alias is that you do not have anymore the information on the previous type.

It would be possible that when resetting a vip alias we try to delete every possible vip type we know, though that might spam logs a bit.
But if you think that is more correct than current behavior than i will try to implement it!