I just installed 7.18.1 version on my Model E50UG and noticed after boot this error on the log:
Buffer: Memory
Topics: dhcp, error
Message: events on master port will be handled by slave ether5, update your config!!! (IPv4)
I’m not 100% was that same error there already before update, so I can’t say that this is related to the new version.
Ether5 port seems to work normally and devices behind that port seems to get internal IP address normally. I have all ports from 2-5 in my bridge and DHCP server is on that bridge interface. Please advice what I should check and why it’s reporting this error. I’m using Winbox as my main configuration tool so if you give instructions, please give step by step instructions what to check.
I’m not sure what information you might need to help me solve this, but here are some basic information what I think is relevant. Let me know commands and part of configuration you need and I can provide. I haven’t much changed the default setup. Only tried to hardening that a little bit based on the documentation.
ip dhcp-server print
Columns: NAME, INTERFACE, ADDRESS-POOL, LEASE-TIME
# NAME INTERFACE ADDRESS-POOL LEASE-TIME
0 defconf bridge default-dhcp 1d
interface print
Flags: R - RUNNING; S - SLAVE
Columns: NAME, TYPE, ACTUAL-MTU, L2MTU, MAX-L2MTU
# NAME TYPE ACTUAL-MTU L2MTU MAX-L2MTU
0 R ether1 ether 1500 1600 2048
1 RS ether2 ether 1500 1596 2026
2 S ether3 ether 1500 1596 2026
3 RS ether4 ether 1500 1596 2026
4 RS ether5 ether 1500 1596 2026
;;; defconf
5 R bridge bridge 1500 1596
6 R lo loopback 65536
interface list member print
Columns: LIST, INTERFACE
# LIST INTERFACE
;;; defconf
0 LAN bridge
;;; defconf
1 WAN ether1
I figured this out. My bad. I forgot that when I initially tried to make rogue-dhcp alert active, I got this same error from different interface based on my own setup documentation. I changed that to ether5 because I got error from ether2. I changed it now to bridge interface and after boot, that error is gone.
Can someone confirm that this is valid way to use DHCP-Alerts? I thought that I can choose any interface I like to run these alerts but it seems it raises this odd error. I didn’t understood this limitation based on this documentation:
As I wrote earlier, it seems problem for this error was alert settings on DHCP server. But as requested, here is list of settings on my setup and dhcp alert settings also in a same post. IP and other sensitive information I masked with xx for my safety.
What I changed, and so far this error won’t raise anymore, I changed alert’s interface from ether5 → bridge. Check my previous post.
So current question is actually, why dhcp-server alert need to run on master port (based on that error) and not in the slave interface? And is this correct way to run alert?
> ip dhcp-server print
Columns: NAME, INTERFACE, ADDRESS-POOL, LEASE-TIME
# NAME INTERFACE ADDRESS-POOL LEASE-TIME
0 defconf bridge default-dhcp 1d
> ip dhcp-server alert print
Columns: INTERFACE, VALID-SERVER, ON-ALERT, ALERT-TIMEOUT
# INTERFACE VALID-SERVER ON-ALERT ALERT-TIMEOUT
0 bridge xx:xx:xx:xx:xx:16 rogue-dhcp 1h
> ip address print
Flags: D - DYNAMIC
Columns: ADDRESS, NETWORK, INTERFACE
# ADDRESS NETWORK INTERFACE
;;; defconf
0 x.x.x.x/x x.x.x.x bridge
1 D x.x.x.xx/xx xx.xx.xx.x ether1
> 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 R ether1 ether 1500 1600 2048 xx:xx:xx:xx:xx:15
1 RS ether2 ether 1500 1596 2026 xx:xx:xx:xx:xx:16
2 S ether3 ether 1500 1596 2026 xx:xx:xx:xx:xx:17
3 RS ether4 ether 1500 1596 2026 xx:xx:xx:xx:xx:18
4 RS ether5 ether 1500 1596 2026 xx:xx:xx:xx:xx:19
;;; defconf
5 R bridge bridge 1500 1596 xx:xx:xx:xx:xx:16
6 R lo loopback 65536 00:00:00:00:00:00
> interface bridge print
Flags: D - dynamic; X - disabled, R - running
0 R ;;; defconf
name="bridge" mtu=auto actual-mtu=1500 l2mtu=1596 arp=enabled arp-timeout=auto mac-address=xx:xx:xx:xx:xx:16 protocol-mode=rstp fast-forward=yes igmp-snooping=no
auto-mac=no admin-mac=xx:xx:xx:xx:xx:16 ageing-time=5m priority=0x8000 max-message-age=20s forward-delay=15s transmit-hold-count=6 vlan-filtering=no
dhcp-snooping=no port-cost-mode=long mvrp=no max-learned-entries=auto
> interface bridge port print
Flags: I - INACTIVE; H - HW-OFFLOAD
Columns: INTERFACE, BRIDGE, HW, PVID, PRIORITY, HORIZON
# INTERFACE BRIDGE HW PVID PRIORITY HORIZON
;;; defconf
0 H ether2 bridge yes 1 0x80 none
;;; defconf
1 IH ether3 bridge yes 1 0x80 none
;;; defconf
2 H ether4 bridge yes 1 0x80 none
;;; defconf
3 H ether5 bridge yes 1 0x80 none
Yeah, I replied to your message where you asked what else was needed. Then I saw the one saying you found it.
That is the correct way of using the dhcp-server alert: it has to be on a L3 interface as it has to run a dhcp client. A port member of a bridge cannot be a dhcp client hence the error.
