netbirdio/netbird · error

'filter' table not found

Error message

'filter' table not found

What it means

Error "'filter' table not found" thrown in netbirdio/netbird.

Source

Thrown at client/firewall/nftables/router_linux.go:64

	userDataAcceptForwardRuleIif = "frwacceptiif"
	userDataAcceptForwardRuleOif = "frwacceptoif"
	userDataAcceptInputRule      = "inputaccept"

	dnatSuffix = "_dnat"
	snatSuffix = "_snat"

	// ipv4TCPHeaderSize is the minimum IPv4 (20) + TCP (20) header size for MSS calculation.
	ipv4TCPHeaderSize = 40
	// ipv6TCPHeaderSize is the minimum IPv6 (40) + TCP (20) header size for MSS calculation.
	ipv6TCPHeaderSize = 60

	// maxPrefixesSet 1638 prefixes start to fail, taking some margin
	maxPrefixesSet       = 1500
	refreshRulesMapError = "refresh rules map: %w"
)

var (
	errFilterTableNotFound = fmt.Errorf("'filter' table not found")
)

type setInput struct {
	set      firewall.Set
	prefixes []netip.Prefix
}

type router struct {
	conn        *nftables.Conn
	workTable   *nftables.Table
	filterTable *nftables.Table
	chains      map[string]*nftables.Chain
	// rules is useful to avoid duplicates and to get missing attributes that we don't have when adding new rules
	rules        map[string]*nftables.Rule
	ipsetCounter *refcounter.Counter[string, setInput, *nftables.Set]

	af               addrFamily
	wgIface          iFaceMapper

View on GitHub (pinned to 93e97f4bf1)

When it happens

Trigger: Thrown at client/firewall/nftables/router_linux.go:64 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of netbirdio/netbird@93e97f4bf1 (2026-08-16). Data as JSON: /api/errors/1094674a62963a78. Report an issue: GitHub.