Routerboard locks me out after specific config

I log into my RB2011UiAS-RM using SSH, and try to change some settings. After changing

/interface ethernet

settings, i lose connectivity. I can no longer ping the router, can no longer SSH into it, and the HTTP server also fails. I can tell from using wireshark that the router replies to ARP requests, but to nothing else.
On the LCD i can see my attempted ICMP ping requests going in, but i can see on the LCD that the router is not even trying to send out ECHO_REPLY.

This is consistent behaviour, i can replicate it consistently, every time. The router becomes unresponsive even when changing the same settings over the web interface.
When configuring the same setting over the serial console there is no problem, everything just keeps working. Am I doing something wrong or is this expected behaviour?

(22:38:06)wizard@ubox:~$
(22:38:07)wizard@ubox:~$ping -v -i 30 -c 1 -w 3600  192.168.0.9
PING 192.168.0.9 (192.168.0.9) 56(84) bytes of data.
64 bytes from 192.168.0.9: icmp_req=1 ttl=64 time=0.763 ms

--- 192.168.0.9 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.112/0.112/0.112/0.000 ms
(22:38:22)wizard@ubox:~$
(22:38:27)wizard@ubox:~$ssh admin@192.168.0.9
The authenticity of host '192.168.0.9 (192.168.0.9)' can't be established.
DSA key fingerprint is 70:7a:c4:7c:01:74:f8:cc:25:3d:33:63:20:09:ea:6e.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.0.9' (DSA) to the list of known hosts.









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  MikroTik RouterOS 6.7 (c) 1999-2013       http://www.mikrotik.com/

[?]             Gives the list of available commands
command [?]     Gives help on the command and list of arguments

[Tab]           Completes the command/word. If the input is ambigous,
                a second [Tab] gives possible options

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[admin@MikroTik] > /interface ethernet 
[admin@MikroTik] /interface ethernet> print
Flags: X - disabled, R - running, S - slave 
 #    NAME                               MTU MAC-ADDRESS       ARP        MASTER-PORT                           SWITCH                          
 0    ether1-mainNet                    1500 00:0C:42:C5:68:0F enabled    none                                  switch1                         
 1 R  ether2                            1500 00:0C:42:C5:68:10 enabled    none                                  switch1                         
 2    ether3                            1500 00:0C:42:C5:68:11 enabled    none                                  switch1                         
 3    ether4                            1500 00:0C:42:C5:68:12 enabled    none                                  switch1                         
 4    ether5                            1500 00:0C:42:C5:68:13 enabled    none                                  switch1                         
 5    ether6                            1500 00:0C:42:C5:68:14 enabled    none                                  switch2                         
 6    ether7                            1500 00:0C:42:C5:68:15 enabled    none                                  switch2                         
 7 XS ether8                            1500 00:0C:42:C5:68:16 enabled    ether6                                switch2                         
 8 XS ether9                            1500 00:0C:42:C5:68:17 enabled    ether6                                switch2                         
 9    ether10                           1500 00:0C:42:C5:68:18 enabled    none                                  switch2                         
10    sfp1-gateway                      1500 00:0C:42:C5:68:0E enabled    none                                  switch1                         
[admin@MikroTik] /interface ethernet> /interface bridge 
[admin@MikroTik] /interface bridge> print
Flags: X - disabled, R - running 
[admin@MikroTik] /interface bridge> port 
[admin@MikroTik] /interface bridge port> print
Flags: X - disabled, I - inactive, D - dynamic 
 #    INTERFACE                                               BRIDGE                                              PRIORITY  PATH-COST    HORIZON
[admin@MikroTik] /interface bridge port> /interface ethernet 
[admin@MikroTik] /interface ethernet> set 7 master-port=none
[admin@MikroTik] /interface ethernet> 
[admin@MikroTik] /interface ethernet> set 8 master-port=none 
[admin@MikroTik] /interface ethernet> print
Flags: X - disabled, R - running, S - slave 
 #    NAME                               MTU MAC-ADDRESS       ARP        MASTER-PORT                           SWITCH                          
 0    ether1-mainNet                    1500 00:0C:42:C5:68:0F enabled    none                                  switch1                         
 1 R  ether2                            1500 00:0C:42:C5:68:10 enabled    none                                  switch1                         
 2    ether3                            1500 00:0C:42:C5:68:11 enabled    none                                  switch1                         
 3    ether4                            1500 00:0C:42:C5:68:12 enabled    none                                  switch1                         
 4    ether5                            1500 00:0C:42:C5:68:13 enabled    none                                  switch1                         
 5    ether6                            1500 00:0C:42:C5:68:14 enabled    none                                  switch2                         
 6    ether7                            1500 00:0C:42:C5:68:15 enabled    none                                  switch2                         
 7 X  ether8                            1500 00:0C:42:C5:68:16 enabled    none                                  switch2                         
 8 X  ether9                            1500 00:0C:42:C5:68:17 enabled    none                                  switch2                         
 9    ether10                           1500 00:0C:42:C5:68:18 enabled    none                                  switch2                         
10    sfp1-gateway                      1500 00:0C:42:C5:68:0E enabled    none                                  switch1                         
[admin@MikroTik] /interface ethernet> set 7 disabled=
no  yes
[admin@MikroTik] /interface ethernet> set 7 disabled=no
[admin@MikroTik] /interface ethernet> set 8 disabled=no 
[admin@MikroTik] /interface ethernet> Connection to 192.168.0.9 closed.
(22:45:42)wizard@ubox:~$
(22:45:44)wizard@ubox:~$ping -v -i 30 -c 1 -w 3600  192.168.0.9
PING 192.168.0.9 (192.168.0.9) 56(84) bytes of data.
^C
--- 192.168.0.9 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

(22:45:54)wizard@ubox:~$ping 192.168.0.9
PING 192.168.0.9 (192.168.0.9) 56(84) bytes of data.
^C
--- 192.168.0.9 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4032ms

(22:46:04)wizard@ubox:~$

Router: RB2011UiAS-RM
RouterOS: v6.7