cilium/cilium · error

unable to parse routing info: %w

Error message

unable to parse routing info: %w

What it means

linuxrouting.NewRoutingInfo failed while building the routing configuration from the IPAM response (gateway, CIDRs, master MAC, interface number). Parsing/validation of the routing inputs rejected them before any rules were installed.

Source

Thrown at plugins/cilium-cni/cmd/interface.go:70

	} else {
		for _, cidr := range ipv6CIDRs {
			coalescedCIDRs = append(coalescedCIDRs, cidr.String())
		}

		masq = conf.MasqueradeProtocols.IPv6
	}

	routingInfo, err := linuxrouting.NewRoutingInfo(
		logger,
		ipam.Gateway.String(),
		coalescedCIDRs,
		ipam.MasterMac,
		ipam.InterfaceNumber,
		conf.IpamMode,
		masq,
	)
	if err != nil {
		return fmt.Errorf("unable to parse routing info: %w", err)
	}

	if err := routingInfo.Configure(
		ip.AddrFromIP(ipConfig.Address.IP),
		int(conf.DeviceMTU),
		false,
	); err != nil {
		return fmt.Errorf("unable to install ip rules and routes: %w", err)
	}

	return nil
}

View on GitHub (pinned to ac7b90affa)

Solutions

1. Log/inspect the full IPAM response (gateway, cidrs, master-mac, interface-number) and find the invalid field
2. Verify the cloud integration (ENI/Azure) is healthy and returning complete interface metadata
3. Check that ipam mode in the DaemonConfigurationStatus matches the IPAM plugin that produced the response
4. Re-create the pod after fixing IPAM state on the agent

Example fix

// before (IPAM response)
{"gateway": "", "cidrs": ["10.0.0.0/24"], "masterMac": ""}
// after
{"gateway": "10.0.0.1", "cidrs": ["10.0.0.0/24"], "masterMac": "02:42:ac:11:00:02"}

// Pre-validate routing inputs before calling the CNI plugin
if ipam.Gateway.IsValid() {
    if len(ipam.Cidrs) == 0 {
        return fmt.Errorf("gateway present but no CIDRs; cloud IPAM metadata incomplete")
    }
    if ipam.MasterMac != "" && net.ParseMAC(ipam.MasterMac) != nil && len(ipam.InterfaceNumber) == 0 {
        return fmt.Errorf("master-mac set but interface-number empty; check ENI/Azure metadata")
    }
}

if err := cniAdd(args); err != nil {
    if strings.Contains(err.Error(), "unable to parse routing info") {
        // log full IPAM response for the pod and alert on cloud-integration health
        logIPAMResponse(args.ContainerID, ipamResp)
        return err
    }
    return err
}

When it happens

Trigger: CNI ADD in ENI/Azure/AlibabaCloud (or delegated) IPAM modes where the gateway string is not a valid IP, CIDR list is empty/inconsistent, or the ipam-mode-specific combination of MasterMac/InterfaceNumber is invalid.

Common situations: Cloud IPAM metadata (ENI attachment info) missing or malformed; gateway field empty while still valid at the top-level check; mixed IPv4/IPv6 CIDR lists confusing the mode-specific parsing.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to create router info: %w
• unable to install ip rule for ENI multi-node NodePort: %w
• unable to install ipv6 ip rule for ENI multi-node NodePort:
• unable to find ENI %s
• failed to add route '%s via %v dev %v': %w

AI-assisted analysis of cilium/cilium@ac7b90affa (2026-08-31). Data as JSON: /api/errors/7a76a8e4ba0ea60a. Report an issue: GitHub.