Hi,

Short story first:

If i define a bridge of 2 ports with no vlan and another bridge of those 2 ports with a vlan, I can't get DHCP to work using those two bridges. Breaking the bridge with no vlan makes the dhcp service come back again in the vlan bridge.

Explanation:

I've got a setup with ubnt's unifi APs, and mikrotik RB750UP as router. UBNT gear has 2 vlans:

-vlan 1 (default): for management.
-vlan 101: for wifi access.

This works OK and has been tested independently.

The mikrotik router has 5 physical ports:

- eth1 and eth2, bridged together (br_local), and used to connect wired local PCs
- eth3 and eth4, used to connect to APs
- eth5, used as uplink

There is defined a vlan (101) in ports eth3 and eth4 (vlan101_eth3 and vlan101_eth4), bridged together (br_hs).

there are three DHCP servers, one tied to br_local (local users), another tied to br_hs (wifi access, vlan 101), and the last one tied to eth3.

This setup works. DHCP is handed correctly. Everything is just fine.

I've found a problem while trying to bridge eth3 and eth4 with no vlan and start the dchp server in that bridge. If I do that, the dchp server tied to the vlan101 bridge (br_hs), fails to work.

I've been testing this for a day now, with v23 adn v25.

I think this is a bug in RoS. Any confirmation ? any clue or workarround?

Some config info follows, this is the config I ended with (no bridge between eth3 and eth4 in vlan default). As a side note, I tested with horizon=none in the bridge, but it made no difference.:

> /interface print
Flags: D - dynamic, X - disabled, R - running, S - slave
# NAME TYPE MTU L2MTU MAX-L2MTU
0 R ether1 ether 1500 1600 4076
1 ether2 ether 1500 1598 2028
2 R ether3 ether 1500 1598 2028
3 ether4 ether 1500 1598 2028
4 R ether5-enlace ether 1500 1598 2028
5 R vlan101_eth3 vlan 1500 1594
6 vlan101_eth4 vlan 1500 1594
7 R br_local bridge 1500 1600
8 R br_hs bridge 1500 1594

> /ip address print
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE
0 192.168.1.2/24 192.168.1.0 ether5-enlace
1 192.168.87.1/24 192.168.87.0 br_local
2 192.168.88.1/24 192.168.88.0 ether3
3 192.168.251.1/24 192.168.251.0 br_hs

> /interface bridge port print
Flags: X - disabled, I - inactive, D - dynamic
# INTERFACE BRIDGE PRIORITY PATH-COST HORIZON
0 ether1 br_local 0x80 10 none
1 I ether2 br_local 0x80 10 none
2 vlan101_eth3 br_hs 0x80 10 1
3 I vlan101_eth4 br_hs 0x80 10 1


> /ip dhcp-server print
Flags: X - disabled, I - invalid
# NAME INTERFACE RELAY ADDRESS-POOL LEASE-TIME ADD-ARP
0 dhcp-locales br_local pool-locales 3d
1 dhcp-hs br_hs pool-hs 1h
2 dhcp-gestion ether3 pool-gestionhs 1h

The full picture isn't clear - e.g. when you bridged Ether 3 & 4 did you move the VLAN 101 interface to the bridge?

I've teste two cases:

* case 1: does not work:

br_mgmt bridges eth3 adn eth4 (no vlan here), ip address 192.168.88.1/24
br_hs bridges vlan101_eth3 and vlan101_eth4, ip address 192.168.251.1/24

started two dhcp servers, one in each bridge. The dhcp server in br_hs does not work.

* case 2: works:

eth3, with no vlan, ip address 192.168.88.1/24
eth4: unconfigured
br_hs bridges vlan101_eth3 and vlan101_eth4, ip address 192.168.251.1/24

started two dhcpservers, one in eth3 and other in br_hs. Both work OK.

Please tell me if it is not clear enough, I'm willing to show further explanations if needed.

Regards

For case 1 try moving the VLAN 101 interface to the br_mgt interface and removing the VLAN 101 interfaces from Ether 3 and 4. Also remove br_hs.

Something like:

> /interface bridge port print
Flags: X - disabled, I - inactive, D - dynamic
# INTERFACE BRIDGE PRIORITY PATH-COST HORIZON
0 ether1 br_local 0x80 10 none
1 I ether2-test br_local 0x80 10 none
2 ether3 bg_gest 0x80 10 none
3 I ether4 bg_gest


> /interface print
Flags: D - dynamic, X - disabled, R - running, S - slave
# NAME TYPE MTU L2MTU MAX-L2MTU
0 R ether1 ether 1500 1600 4076
1 ether2-test ether 1500 1598 2028
2 R ether3 ether 1500 1598 2028
3 ether4 ether 1500 1598 2028
4 R ether5-enlace ether 1500 1598 2028
5 R br_local bridge 1500 1600
6 R bg_gest bridge 1500 1598
7 R br_hs vlan 1500 1594

> /interface vlan print
Flags: X - disabled, R - running, S - slave
# NAME MTU ARP VLAN-ID INTERFACE
0 R br_hs 1500 enabled 101 bg_gest

????

Yes - avoids bridge within a bridge.