Tom Eastep 2005-04-10 2004 2005 Thomas M. Eastep Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover, and with no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.

Shorewall can produce a wide variety of error messages when a problem is detected with your configuration. This article attempts to explain the cause of and cures for some of these messages.

Some error messages are produced by the /sbin/shorewall utility. These messages are detailed in this section. ERROR: <label> must specify a simple file name: <name> This means that you have specified a restore file name with a "/". Restore files must be simple file names with no slashes. ERROR: Shorewall is not properly installed The files /usr/share/shorewall/firewall and/or /usr/share/shorewall/version do not exist. ERROR: <file name> exists and is not a saved Shorewall configuration The named file in /var/lib/shorewall exists but is not executable. ERROR: Reserved file name: <file name> You have specified either save or restore-base as the name of a restore file -- those names are reserved for use by Shorewall. ERROR: Currently-running Configuration Not Saved During processing of a shorewall save command, the iptables-save command failed. ERROR: /var/lib/shorewall/restore-base does not exist The shorewall start and shorewall restart commands create a file called /var/lib/shorewall/restore-base which forms the basis for creating a restore file using shorewall save. This error message is issued when shorewall save is not able to find that file.

The program /usr/share/shorewall/firewall is responsible for parsing the Shorewall configuration files and for creating and changing the Netfilter configuration. Some of the error messages generated by this program are listed below. ERROR: Invalid zone definition for zone <zone> The zone named in the message is defined to be associated with an interface in /etc/shorewall/interfaces yet it also has an entry for that same interface in /etc/shorewall/hosts. ERROR: Invalid zone (<zone>) in record "<record>" The zone named in the ZONE column of the listed record from /etc/shorewall/interfaces or /etc/shorewall/hosts is not defined in /etc/shorewall/zones. ERROR: Duplicate Interface <interface> The named interface has two entries in /etc/shorewall/interfaces. ERROR: Invalid Interface Name: <interface> The interface name contains a colon (":") or is "+". If the name includes a ":", you probably need to read this article. ERROR: Unknown interface (<interface>) in record "<record>" The <interface> name listed in the <record> from /etc/shorewall/hosts was not defined in /etc/shorewall/interfaces. ERROR: Bridged interfaces may not be defined in /etc/shorewall/interfaces: <interface>[:<address>] The named interface appears in /etc/shorewall/hosts and appears as a bridge port (after a colon) but is also defined in /etc/shorewall/interfaces. ERROR: Your kernel and/or iptables does not support policy match: ipsec You have specified the ipsec option in an /etc/shorewall/hosts record but your kernel and/or iptables is missing policy match support. That support in turn requires a set of ipsec-netfilter patches in order to work correctly. ERROR: Undefined zone <zone> The named zone appears in the /etc/shorewall/policy file but not in the /etc/shorewall/zones file. ERROR: Can't determine the IP address of <interface> You have specified DETECT_DNAT_ADDRS=Yes in /etc/shorewall/shorewall.conf and Shorewall is unablee to determine the IP address of the named <interface>. Be sure that the interface is started before starting Shorewall or set DETECT_DNAT_ADDRS=No. ERROR: Invalid gateway zone (<zone>) -- Tunnel "<record> The listed <zone> name appears in the GATEWAY ZONE column of the listed <record> from /etc/shorewall/tunnels but is not defined in /etc/shorewall/zones. ERROR: Your kernel and/or iptables does not support policy match Your /etc/shorewall/ipsec file is non-empty but your kernel and/or iptables do not include policy match support. That support in turn requires a set of ipsec-netfilter patches in order to work correctly. ERROR: No hosts on <interface> have the maclist option specified The named <interface> appears in a record in /etc/shorewall/maclist yet that interface's record in /etc/shorewall/interfaces does not specify the maclist option and no record in /etc/shorewall/hosts that names that interface includes the maclist option. ERROR: Interface <interface> must be up before Shorewall can start You have specified the maclist option for this interface but the command ip list show <interface> fails. ERROR: Unknown interface <interface> The interface appears in a configuration file but is not defined in /etc/shorewall/interfaces. ERROR: BRIDGING=Yes requires Physdev Match support in your Kernel and iptables You have set BRIDGING=Yes in /etc/shorewall/shorewall.conf but it appears that your kernel and/or iptables do not have physdev match support. ERROR: Unknown interface <interface> in rule: "<rule>" You have BRIDGING=No in /etc/shorewall/shorewall.conf and the <interface> given in a rule does not match an entry in /etc/shorewall/interfaces. ERROR: SNAT may no longer be specified in a DNAT rule; use /etc/shorewall/masq instead In earlier Shorewall versions, the ORIGINAL DEST column allowed following the original destination IP address with ":" and an address to use as the source of the forwarded connection request. Now that /etc/shorewall/masq supports qualification of SNAT rules by protocol and port, this feature is no longer required and has been deimplemented. ERROR: "Invalid Source in rule "<rule>" The SOURCE column has the firewall zone name immediately followed by "!". This syntax is use to exclude a subzone and Shorewall currently doesn't support subzones of the firewall zone. ERROR: Rule "<rule>" - Destination may not be specified by MAC Address Netfilter (and hence Shorewall) does not allow qualification of a rule by destination source IP address. ERROR: Destination interface not allowed with <action> The named <action> will be ACCEPT+ or NONAT. These actions are inforced in part in the PREROUTING nat chain where the destination interface is not yet known (because the packet has not yet been routed). As a result, the DESTINATION column may not contain an interface name. ERROR: Only DNAT and REDIRECT rules may specify destination mapping; rule "<rule>" The <rule> specifies a server address that is different from the ORIGINAL DEST address and/or it specifies a server port that is different from the destination port but the ACTION is neither DNAT[-] nor REJECT[-]. ERROR: Empty source zone or qualifier: rule "<rule>" The SOURCE column is of one of the forms <zone>:, :<qualifier> or :. ERROR: Exclude list only allowed with DNAT or REDIRECT In DNAT[-] and REDIRECT[-] rules, you can have a SOURCE of the form <zone>:<net1>!<net2>. This means <net1> in the <zone> zone except for <net2>. This syntax is not available with other ACTIONs. ERROR: Invalid use of a user-qualification: rule "<rule>" The USER/GROUP column may only have and entry if the SOURCE is the firewall zone. ERROR: Empty destination zone or qualifier: rule "<rule>" The DEST column is of one of the forms <zone>:, :<qualifier> or :. ERROR: Undefined Client Zone in rule "<rule>" The zone given in the SOURCE column was not defined in /etc/shorewall/zones. ERROR: Undefined Server Zone in rule "<rule>" The zone given in the DEST column was not defined in /etc/shorewall/zones. ERROR: Rules may not override a NONE policy: rule "<rule>" If the policy from zone z1 to zone z2 is NONE that means that Shorewall sets up no infrastructure to handle traffic from z1 to z2. Consequently, you cannot have any rules that control traffic from z1 to z2. ERROR: Invalid Action in rule "<rule>" The ACTION column contains an action that is not one of the built-in actions and it is not defined in /etc/shorewall/actions or in /usr/share/shorewall/actions.std. ERROR: Unable to determine the routes through interface <interface> You have specified <interface> in the SUBNET column of /etc/shorewall/masq which means that Shorewall is supposed to determine the network(s) routed through that interface. To do that, Shorewall issues the command ip addr ls dev <interface> and that command failed. This usually means that you are trying to start Shorewall before the <interface> is brought up. ERROR: No appropriate chain for zone <z1> to zone <z2> There is no policy defined in /etc/shorewall/policy for connections from zone <z1> to zone <z2>.

This sections describes some of the more common warnings generated by Shorewall. Warning: default route ignored on interface <interface> This means that the interface named in the SUBNET column of /etc/shorewall/masq has the default route. This almost always means that you have the contents of the INTERFACE and SUBNET columns reversed. Warning: Zone <zone> is empty This warning alerts you to the fact tha <zone> is defined in /etc/shorewall/zones but has no corresponding entries in /etc/shorewall/interfaces or in /etc/shorewall/hosts.

By far the most asked about iptables error message is: iptables: No chain/target/match by that name This almost always means that you are trying to use a Shorewall feature that your iptables and/or kernel do not support. Beginning with version 2.2.0, Shorewall follows this message with a copy of the iptables command that is failing. Most commonly, the problem is that one of the match types (keyword following "-m" in the command) isn't supported by your iptables/kernel. The output of "shorewall check" shows you what your iptables/kernel support: gateway:~# shorewall check Loading /usr/share/shorewall/functions... Processing /etc/shorewall/params ... Processing /etc/shorewall/shorewall.conf... Loading Modules... Shorewall has detected the following iptables/netfilter capabilities: NAT: Available Packet Mangling: Available Multi-port Match: Available Extended Multi-port Match: Available Connection Tracking Match: Available Packet Type Match: Not available Policy Match: Available Physdev Match: Available IP range Match: Available Verifying Configuration... ...