Can't flush static DNS entries

RouterOS General
1

If you create static DNS entries, then disable them, then flush the DNS cache, the static entries remain cached until the next reboot. There does not seem to be a way to flush them besides rebooting.

I understand this isn’t quite a big problem for 99.99% of people, but it’s a major pain in the ass for me in my home network, when testing servers (i.e. swapping back and forth between “true” DNS entries and temporarily swapped IP addresses for the test servers).

This is on 6.2, RB2011, by the way.

2

5.25 has the same issue.
The previous dns entries remain in cache and you get them returned in order.
Only reboot solves this.

3

On v. 5.25:
I disable static records and they disappear from DNS cache immediatelly. Then I remove them and they are gone forever.
No need for restart…

4

I have exactly same issue on 6.20 now.
Except rebooting is not helps.

5

do you have any clue what request caused this? Is this crowded dns-cache?

6

Exactly the same problem. Deleted static DNS record is still in cache. ROS 6.27, RB2011.

7

It happens only when there are lot of items in DNS cache.

[SOLUTION] You can use this steps until the fix arrives..

Before deleting Static DNS entries:

  1. first flush dns cache

  2. delete static entries.



    If there are leftover entries:

  3. first flush dns cache

  4. recreate static entries with the same hostname / IP combination.

  5. delete the same static entries.

Hope this helps.

8

I already sent suppout and video, how it happend. It hapens when you rename static entry. Then the previous one trapp in cache.

9

The situation when it happen: https://www.youtube.com/watch?v=CF6RvVPpxGM

10

Thanks, it works

11

Only if there is a lot of items? I exactly found, the reason when it happend. See my video above.