ipfs/kubo · error

incorrectly formatted address filter in config: %s

Error message

incorrectly formatted address filter in config: %s

What it means

When building the libp2p host, each entry of Swarm.AddrFilters is parsed as a CIDR-style address mask (via mamask.NewMask, e.g. "/ip4/10.0.0.0/ipcidr/24"). An entry that cannot be parsed aborts node construction with this error, naming the offending filter string.

Source

Thrown at core/node/libp2p/addrs.go:33

	"github.com/libp2p/go-libp2p/core/event"
	"github.com/libp2p/go-libp2p/core/host"
	p2pbhost "github.com/libp2p/go-libp2p/p2p/host/basic"
	ma "github.com/multiformats/go-multiaddr"
	manet "github.com/multiformats/go-multiaddr/net"
	mamask "github.com/whyrusleeping/multiaddr-filter"

	"github.com/caddyserver/certmagic"
	"go.uber.org/fx"
)

func AddrFilters(filters []string) func() (*ma.Filters, Libp2pOpts, error) {
	return func() (filter *ma.Filters, opts Libp2pOpts, err error) {
		filter = ma.NewFilters()
		opts.Opts = append(opts.Opts, libp2p.ConnectionGater((*filtersConnectionGater)(filter)))
		for _, s := range filters {
			f, err := mamask.NewMask(s)
			if err != nil {
				return filter, opts, fmt.Errorf("incorrectly formatted address filter in config: %s", s)
			}
			filter.AddFilter(*f, ma.ActionDeny)
		}
		return filter, opts, nil
	}
}

// Sources for deadListenerFinding.Source.
const (
	deadListenerSourceAddrFilters = "Swarm.AddrFilters"
	deadListenerSourceNoAnnounce  = "Addresses.NoAnnounce"
)

// deadListenerFinding is one resolved listener whose IP falls inside a
// CIDR in `Swarm.AddrFilters` (gater RSTs inbound) or
// `Addresses.NoAnnounce` (listener never advertised).
type deadListenerFinding struct {
	Listener string // resolved listen multiaddr (interface-bound)

View on GitHub (pinned to 329838acdf)

Solutions

1. Run `ipfs config Swarm.AddrFilters` and fix the offending entry to multiaddr mask form, e.g. "/ip4/192.168.0.0/ipcidr/16" or "/ip6/fc00::/ipcidr/7"
2. Validate the multiaddr with `ipfs multiaddr /ip4/10.0.0.0/ipcidr/8` before writing it to config
3. Remove stale/invalid entries entirely if you no longer need that filter

Example fix

// before (config.json)
"Swarm": { "AddrFilters": ["10.0.0.0/8"] }
// after
"Swarm": { "AddrFilters": ["/ip4/10.0.0.0/ipcidr/8"] }

for _, s := range cfg.Swarm.AddrFilters {
    if _, err := mamask.NewMask(s); err != nil {
        return fmt.Errorf("invalid Swarm.AddrFilters entry %q: %w", s, err)
    }
}

When it happens

Trigger: Starting the daemon with a Swarm.AddrFilters entry that is not a valid multiaddr mask — wrong multiaddr syntax, unsupported protocol, or typo — in the config.

Common situations: Copying filters from IPv4 examples for IPv6 (or vice versa); hand-written masks like "10.0.0.0/8" (plain CIDR, not multiaddr) instead of "/ip4/10.0.0.0/ipcidr/8"; leftover entries from very old kubo versions with outdated syntax.

Related errors

• serveHTTPApi: invalid API address: %q (err: %s)
• serveHTTPGateway: invalid gateway address: %q (err: %s)
• serveHTTPGateway: manet.ToNetAddr() failed: %w
• conn not found
• unrecognized Swarm.ConnMgr.Type: %q

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/7994cc0034018126. Report an issue: GitHub.