Can I connect to unprotected Wifi ?

[e1-531g]

Hello. I would like to connect to unprotected Wifi. I am aware of risk of this.
My operating system:

kern.version=OpenBSD 6.1-current (GENERIC.MP) #73: Sat Jul  1 10:53:54 MDT 2017
    deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP

I have said unprotected. I mean by this lack of WEP/WPA/WPA2, basically anything based on cryptography to authenticate and authorize access. This network restricts access based on MAC addresses, but my MAC is added by admin of this public network. I can connect to this network from the same laptop using Windows operating system, so this is not hardware problem.
I have Wifi network device supported by iwn(4) driver.
Fun thing is that I managed to connect to WPA2-Personal without any problems, but I am stuck at connecting to unprotected Wifi.

I would like to anonymise at least some info, but if you think I censor too much tell me about this.

I see the network existence via command (nwid name is altered, but really contains spaces):

# ifconfig iwn0 scan
                nwid "word1 space word2" chan 6 bssid 80(censored)e5 -49dBm HT-MCS23 short_preamble,short_slottime

but there are other Wifi networks with the same nwid (they are legitimate, there are several APs to this network).

I have instructed iwn(4) driver to connect to this network by this file:

# cat /etc/hostname.iwn0                                                       
media autoselect mode 11n
nwid "word1 space word2"
dhcp

This gives me:

# ifconfig iwn0
iwn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	lladdr 00:(censored):cc
	index 2 priority 4 llprio 3
	groups: wlan
	media: IEEE802.11 autoselect (DS1 mode 11g)
	status: no network
	ieee80211: nwid "word1 space word2" chan 6 bssid 80:(censored):e5 -49dB

Some info from Windows when connected to this Wifi network:

ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : (censored)
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : (censored).pl

Wireless LAN adapter Wi-Fi 2:

   Connection-specific DNS Suffix  . : (censored).pl
   Description . . . . . . . . . . . : Intel(R) Centrino(R) Advanced-N 6200 AGN
   Physical Address. . . . . . . . . : 00-(censored)CC
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::(censored)2263%30(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.(censored).136(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.128
   Lease Obtained. . . . . . . . . . : 5 7 2017 22:15:19
   Lease Expires . . . . . . . . . . : 5 7 2017 22:25:17
   Default Gateway . . . . . . . . . : 10.(censored).129
   DHCP Server . . . . . . . . . . . : 10.(censored).0
   DHCPv6 IAID . . . . . . . . . . . : 5(censored)6
   DHCPv6 Client DUID. . . . . . . . : 00-(censored)-70

   DNS Servers . . . . . . . . . . . : 10.(censored).129
                                       212.(censored).177
   NetBIOS over Tcpip. . . . . . . . : Enabled