We have around 300 MikroTik routers in active use and have noticed that some appear to have excessive RAM usage, i.e. over a period of days RAM usage increases. Some older routers with only 32MB of RAM fail and lockup when down to under 2MB of free memory.
I have spent a lot of time trying to find something common between those routers that do suffer excessive RAM usage and those the don’t, but so far have been unable to.
We have had to resort to doing a nightly scheduled reboot, but would really like to find a permanent solution.
All routers are on v5.12, all have an OpenVPN connection, most have Hotspot enabled. Hardware is a mixture of 450, 450G, 750, 750G, 411, 433 and 493.
If i remember correctly, v5.12 had a problem with routing cache that it wouldn’t free the old entries. try to monitor ‘/ip route cache print’ for a while to confirm this.
either way, i suggest to update your routers from that version to a more stable one.
Hmmm, don’t think the problem is with routing cache, the affected Routers only have a couple of routes on them and they’re all static.
v5.12 seems otherwise pretty stable, have been contemplating upgrading to v5.14, but there were no bug fixes/new features documented in the Release Notes that really seemed relevant to us.
Also problem was occurring before v5.12, right back to v4.10 and probably earlier. It only seems to happen on Hotspot routers, we don’t seem to have the issue on MT routers used purely as APs. However, the AP routers are RB433 with 128MB of RAM so not really an issue if the router decides to grab and not release 50MB of RAM or more.
This would point to either an issue in the Hotspot, DHCP Server or Firewall.
I’m particularly suspicious of a memory leak in the DHCP Server, as the problem seems to be more prevalent at sites where there are large numbers of people wandering around with handheld Wifi devices constantly switching from one AP to another and hence high(ish) volumes of DHCP requests.
Routing cache has got nothing to do with the amount of routes you have or whether they are statics or not. its about how many different destination addresses is being requested by different source addresses. basically, the more users you serve, the faster routing cache will filled up.
anyway, probably the best way to track down your problem, would be creating a support file, when the ram is almost full and email that the support team. however, they’ll most likely advise you to upgrade to the latest version first.
Also, we’ve seen it over and over again that Mikrotik don’t include all changes they make in a new release, in the change log. they claim its impossible to keep track of every small change. so just because its not mentioned there, doesn’t necessarily mean there’s been no change.
Hi, i find this threas but i see that’s very old, i have noticed the same problem on my RouterOS x86. The i have version 6.1. Someone found what was the problem?
