I’ve come across a 100% repeatable problem whereby several Synaccess NP-05B power controllers fail to negotiate DHCP leases on several contemporary Mikrotik routers, including RB2011 and Cloud Cores. Before I resume sniffing packets, I can’t imagine that we’re the first group to pair these devices in this combination. Three interesting data points:
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- The Synaccess Ethernet interface only seems to support 10 mb half-duplex operation.
- The Synaccess NP-05B DHCP client negotiates successfully on several other brand routers.
- The Synaccess NP-05B works just fine through the Mikrotiks when assigned a static address.
This is neither an academic exercise nor a criticism, I have a handful of remote sites where dropping-in one of these DHCP-enabled controllers is likely.
Have any esteemed forum members dealt with this combo successfully, or given up on it?
ROS Version? Is DHCP set to authoritative?
If using latest bug fix, take a support while experiencing the issue and write to support attaching it.
If not, try bug fix version. Are you creating static DHCP leases for the Synaccess?
There are some other topics about problems between certain clients and the MikroTik DHCP server, e.g. about some mediaplayer.
I have also experienced one case myself, where the controller of an electric car charging post would get a valid lease from a MikroTik router but fails to extend it once its lease time expires.
(I fixed that using a script that disables/enables the switchport once a week until I have time to trace what happens and submit a bugreport)
The core of the issue usually is that the client has some bug in its DHCP request or reply processing (certain fields incorrectly set) and some DHCP servers do not care about it but the MikroTik server somehow fails under these conditions.
Recently there have been some changes in this area, and a couple of times these changes, although the undoubtedly fixed a certain problem, caused new problems for others.
I would say it is not that simple, and as pukkita already posted the version of RouterOS is important to know.
The media configuration (10 Mbps halfdup) does not matter, although of course it has to be setup correctly. Automatic should be fine. Those simple devices that use networking only for monitoring and basic control sometimes have a slow network interface, especially when they are not recent designs. I would not worry about that.
Please post the interface stats, Rx, Tx, overall.
There has been lots if changes in L2 implementation in ROS recently.
What happens if you put a switch in between? Any difference?
I couldn’t agree more with jarda, on top of that mikrotik tries to avoid spaguetti code to fix other’s bugs.
Post a packet capture…