Switch works, except for internet

RouterOS Beginner Basics
1

Hi, I am new to MikroTik, so I may be doing something straight up stupid :smiley:

I have a MikroTik CRS312-4C+8XG running as a switch on RouterOS 7.13.4.
Uplink on SFP+ port 1 to a Unifi switch and gateway.

Interestingly / annoyingly:

  • Internet works upstream (in the unifi part of the network)


  • Internet sometimes works from the Mikrotik switch but drops off now and then (and it has been down for a while now)


  • I can access my entire network from the Mikrotik switch, but not the internet


  • When trying to checking for updates on the switch, I get a ‘could not resolve dns name’ error

This would suggest to me a DNS issue, but have not been able to resolve it.. Any suggestions?
(I have tried purging the DNS cache, without effect.)

See below more details. Thanks!

[admin@MikroTik] > /interface print 
Flags: R - RUNNING; S - SLAVE
Columns: NAME, TYPE, ACTUAL-MTU, L2MTU, MAX-L2MTU, MAC-ADDRESS
 #    NAME    TYPE    ACTUAL-MTU  L2MTU  MAX-L2MTU  MAC-ADDRESS      
 0  S combo1  ether         1500   1584      10218  2C:C8:1B:DB:75:56
 1  S combo2  ether         1500   1584      10218  2C:C8:1B:DB:75:57
 2 RS combo3  ether         1500   1584      10218  2C:C8:1B:DB:75:58
 3 RS combo4  ether         1500   1584      10218  2C:C8:1B:DB:75:59
 4  S ether1  ether         1500   1584      10218  2C:C8:1B:DB:75:4E
 5  S ether2  ether         1500   1584      10218  2C:C8:1B:DB:75:4F
 6 RS ether3  ether         1500   1584      10218  2C:C8:1B:DB:75:50
 7  S ether4  ether         1500   1584      10218  2C:C8:1B:DB:75:51
 8  S ether5  ether         1500   1584      10218  2C:C8:1B:DB:75:52
 9  S ether6  ether         1500   1584      10218  2C:C8:1B:DB:75:53
10  S ether7  ether         1500   1584      10218  2C:C8:1B:DB:75:54
11  S ether8  ether         1500   1584      10218  2C:C8:1B:DB:75:55
12  S ether9  ether         1500   1598       2028  2C:C8:1B:DB:75:5A
;;; defconf
13 R  bridge  bridge        1500   1584             2C:C8:1B:DB:75:56
[admin@MikroTik] > /ip address print 
Flags: D - DYNAMIC
Columns: ADDRESS, NETWORK, INTERFACE
#   ADDRESS            NETWORK        INTERFACE
0 D 192.168.241.52/24  192.168.241.0  bridge   
[admin@MikroTik] > /ip route print 
Flags: D - DYNAMIC; A - ACTIVE; c - CONNECT, d - DHCP
Columns: DST-ADDRESS, GATEWAY, DISTANCE
    DST-ADDRESS       GATEWAY        DISTANCE
DAd 0.0.0.0/0         192.168.241.1         1
DAc 192.168.241.0/24  bridge                0
[admin@MikroTik] >
2

I assume that your gateway is 192.168.241.1, right? Do you see its mac address in ARP? Can you ping it?

Since Mikrotik works as plain L2 switch here (and doesn’t do any routing) I doubt that it affects your Intertnet connection somehow (unless you have broken cables or ports of course).

As for DNS error, you should set DNS server of Mikrotik itself, try 1.1.1.1 or 8.8.8.8 or the one provided by your ISP:
https://help.mikrotik.com/docs/display/ROS/DNS#DNS-DNSconfiguration

Which one is used by computers in your LAN btw?

3

Ok, after extensive frustration, and breaking the whole thing at some point, it works again, but only at 1 GbE :s
Since this is possibly a different issue, I will start a new thread.
Thanks @IIKa!