RB2011L DHCP not working on eth6

nabas · Sat Jul 28, 2012 12:10 am

Dear All,

I've a trouble with my new RB2011L (ROS v. 5.19): it has 5 gigabit ethernet port and 5 fast ethernet port. All the ports are routed ports connected to different IP networks. DHCP server seems to be not active on eth6 interface. I think the problem could be caused by the fact eth6 is assigned to switch2:

[admin@mt.pinetana.bigip.it] > /interface ethernet print        
Flags: X - disabled, R - running, S - slave 
 #    NAME                                         MTU MAC-ADDRESS       ARP        MASTER-PORT                                       SWITCH
 0 R  eth1-adsl                                   1500 00:0C:42:F3:5A:BA enabled    none                                              switch1                                
 1 R  eth2-ap-bar                                 1500 00:0C:42:F3:5A:BB enabled    none                                              switch1                                 
 2     eth3-ap-marco                               1500 00:0C:42:F3:5A:BC enabled    none                                              switch1                               
 3 R  eth4-mtbaselga                              1500 00:0C:42:F3:5A:BD enabled    none                                              switch1                              
 4 R  eth5-dvr                                    1500 00:0C:42:F3:5A:BE enabled    none                                              switch1                                   
 5 R  eth6-gelateria                              1500 00:0C:42:F3:5A:BF enabled    none                                              switch2                                 
 6    eth7-appartamento                           1500 00:0C:42:F3:5A:C0 enabled    none                                              switch2                              
 7    ether8                                      1500 00:0C:42:F3:5A:C1 enabled    none                                              switch2                                   
 8    ether9                                      1500 00:0C:42:F3:5A:C2 enabled    none                                              switch2                                    
 9    ether10                                     1500 00:0C:42:F3:5A:C3 enabled    none                                              switch2                  


[admin@mt.pinetana.bigip.it] > /interface ethernet switch print 
Flags: I - invalid 
 #   NAME                                      TYPE         MIRROR-SOURCE                                      MIRROR-TARGET                                      SWITCH-ALL-PORTS
 0   switch1                                   Atheros-8327 none                                               none                                              
 1   switch2                                   Atheros-8227 none                                               none

Furthermore I assigned a static IP address on eth6 and I connected my laptod directly to the port with a static ip configuration: I can't ping the IP address assigned to the port. It's very strange...

Any suggestions will be appreciated!

Many thanks.

Alberto

hassibi · Sat Jul 28, 2012 8:11 pm

is eth1 a member of a bridge?

cbrown · Sun Jul 29, 2012 5:12 am

Post /export compact

nabas · Sun Jul 29, 2012 3:14 pm

Dear all,

last night I solved all my problems. I changed the default VLAN mode for interface eth6 from "fallback" to "disabled". Sincerly I don't know why eth6 was in fallback mode. I found the same configuration issue in a second different RB2011. I think it is a Mikrotik default. On the other hand eth7<->eth10 have vlan mode set to "disabled".

I tried to deeply understand how Mikrotik switching works. I read the wiki http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features but for a beginner is not so easy. Does someone know a more explained discussion about this topic with examples?

Thank you very much.

Alberto

mrz · Mon Jul 30, 2012 11:27 am

I have several RB2011 on the table and none of them have set VLAN mode. Also default configuration is not touching vlan modes at all.

Can you repeat the problem by doing system reset?

nabas · Mon Jul 30, 2012 3:30 pm

Hi mrz,

I'm sorry but I can't reset the routerboards because they're in production and my table is empty!
If I have a RB2011 the test I would like to do is importing the attached configuration to try to reproduce the issue.
The configuration is referred to a RB750G which has been burned by a lightning. To import the configuration to the RB2011 I only removed the mac-address of the ethernet interfaces.

Regards,
Alberto

zervan · Wed Mar 27, 2013 10:01 pm

Today I was solving exactly the same problem on RB2011L - switch1 group (ether2-5 ports) bridged together with switch2 group (ether6-10 ports), DHCP was not working on switch2 ports.

I've spent a lot of time to realize that switch2 ports are not working at all if their VLAN Mode is set to fallback - it doesn't matter if they are part of a bridge or not. I started Packet Sniffer and all received packet from switch2 were marked as VLAN 1. Why? Switch1 is working fine in fallback mode.

zervan · Mon Apr 15, 2013 6:31 pm

I've spent a lot of time to realize that switch2 ports (on RB2011) are not working at all if their VLAN Mode is set to fallback - it doesn't matter if they are part of a bridge or not. I started Packet Sniffer and all received packet from switch2 were marked as VLAN 1. Why? Switch1 is working fine in fallback mode.

This will be fixed in v6.0rc14