Flint 2: Netlink receive failure: Out of memory

anas4096 · November 27, 2025, 1:01pm

I see many error out of memory, i have always free memory on router (v4.8.3-op24),

I use banip, all world is blocked only my country is whitelisted

Thu Nov 27 10:47:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 10:47:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 10:57:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 10:57:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:07:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:07:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:17:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:17:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:27:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:27:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:37:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:37:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:47:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:47:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 11:57:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 11:57:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available
Thu Nov 27 12:07:22 2025 daemon.err nlbwmon[7533]: Netlink receive failure: Out of memory
Thu Nov 27 12:07:22 2025 daemon.err nlbwmon[7533]: Unable to dump conntrack: No buffer space available

will.qiu · November 28, 2025, 3:54am

Hi

This appears to be a known issue with nlbwmon:

github.com/jow-/nlbwmon

Netlink receive failure: Out of memory

opened 10:35PM - 22 Dec 20 UTC

closed 11:32AM - 15 Sep 21 UTC

klingon888

I'm getting the following errors every few hours: `daemon.err nlbwmon[21812]: N…etlink receive failure: Out of memory` `daemon.err nlbwmon[21812]: Unable to dump conntrack: No buffer space available` My stats: `# cat /proc/sys/net/netfilter/nf_conntrack_count 632` `# cat /proc/sys/net/netfilter/nf_conntrack_max 16384` I've already increased buffer size to 100M and restarted nlbwmon but still getting these errors. Also changed the Commit interval to 1hr, hoping that this commit will flush the buffer after writing to the database but not helping. Strange this is, even after increasing the buffer to 100M and running for a few hrs and getting this error, my total memory usage still shows the same. I'd think it will increase by 100M?? How to fix this? Thanks.

Please try manually adjusting the following Linux kernel parameters to see if it improves the situation:

sysctl -w net.core.rmem_default=16777216 \
net.core.wmem_default=16777216 \
net.core.rmem_max=16777216 \
net.core.wmem_max=16777216

If this resolves the issue, you can add these settings to /etc/sysctl.conf so they are applied automatically at boot:

echo "net.core.rmem_default=16777216
net.core.wmem_default=16777216
net.core.rmem_max=16777216
net.core.wmem_max=16777216" >> /etc/sysctl.conf