NPPPD.CONF(5)

NAME
npppd.conf - npppd configuration file

DESCRIPTION
npppd.conf is the configuration file for the PPP daemon npppd(8).

SECTIONS
npppd.conf is divided into six sections:

Global
    Global settings.
Tunnel
    Tunneling protocol and PPP settings.
IPCP
    Internet Protocol Configuration Protocol (IPCP) of PPP.
Interface
    Interface settings.
Authentication
    Authentication settings.
Bind
    Bind settings.

GLOBAL
The global options are as follows:

set max-session number
    Specify the maximum number of sessions. ‘0’ means no limit. The default value is 0.

set user-max-session number
    Specify the maximum number of sessions for each user. ‘0’ means no limit. The default value is 0.

TUNNEL
The tunnel setting is described below:

tunnel name protocol protocol [option ...]

Specify the tunnel protocol:

l2tp
    Layer Two Tunneling Protocol (RFC 2661)
pppoe
    PPP Over Ethernet (RFC 2516)
pptp
    Point-to-Point Tunneling Protocol (RFC 2637)

The supported options are as follows:

listen on address [port port]
    Specify the IP address that this tunnel listens on. Both IPv4 and IPv6 addresses can be used for L2TP. Only IPv4 address can be used for PPTP. If the port is omitted, the default port numbers are used. The default port numbers are 1723 for PPTP and 1701 for L2TP. The default value is 0.0.0.0. This option is for PPTP and L2TP only. This option can be used multiple times.

listen on interface interface-name
    Specify the interface name that this PPPoE tunnel listens on. The interface must be an Ethernet interface. This option is for PPPoE only.

l2tp-hostname string
    Specify an L2TP hostname. The default value is the value that is returned by gethostname(3). This option is for L2TP only.

l2tp-vendor-name string
    Specify an L2TP vendor name. The default value is "" (an empty string). This option is for L2TP only.

l2tp-hello-interval number
    Specify the interval time between L2TP hello requests, in seconds. The default value is 60. This option is for L2TP only.

l2tp-hello-timeout number
    Specify the maximum time that npppd(8) waits for L2TP hello responses, in seconds. The default value is 30. This option is for L2TP only.

l2tp-accept-dialin yes | no
    If “yes” is specified, npppd(8) accepts Proxy-LCP and Proxy-Authentication AVPs from LAC to do “compulsory tunneling mode”. The default is “no”. This option is for L2TP only.

l2tp-lcp-renegotiation yes | no
    If “yes” is specified, npppd(8) will basically use the LCP that is received by Proxied-LCP AVPs, but if the LCP is not acceptable npppd(8) will negotiate LCP again. The default is “yes”. This option is for L2TP only.

l2tp-force-lcp-renegotiation yes | no
    If “yes” is specified, npppd(8) will not use the LCP that is received by Proxied-LCP AVPs, it will negotiate LCP again. The default is “no”. This option is for L2TP only.

l2tp-data-use-seq yes | no
    Specify “yes” to use sequencing for L2TP Data communications. The default is “yes”. This option is for L2TP only.

l2tp-require-ipsec yes | no
    Specify “yes” to refuse L2TP connections without IPsec encapsulation. The default is “no”. This option is for L2TP only.

pptp-hostname string
    Specify a PPTP hostname. The default value is "" (an empty string). This option is for PPTP only.

pptp-vendor-name string
    Specify a PPTP vendor name. The default value is "" (an empty string). This option is for PPTP only.

pptp-echo-interval number
    Specify the interval time between PPTP echo requests, in seconds. The default value is 60. This option is for PPTP only.

pptp-echo-timeout number
    Specify the maximum time that npppd(8) waits for PPTP echo replies, in seconds. The default value is 60. This option is for PPTP only.

pppoe-service-name string
    Specify a service name. The default is "" (an empty string). This option is for PPPoE only.

pppoe-accept-any-service yes | no
    If “yes” is specified npppd(8) accepts requests from clients that are accepting any service names. The default value is “yes”. This option is for PPPoE only.

pppoe-ac-name string
    Specify the access concentrator (AC) name. The default value is created by the MAC address of the listening interface. This option is for PPPoE only.

mru number
    Specify the Maximum Receive Unit (MRU). This value is used for LCP negotiation to ask the peer not to send packets greater than the MRU octets. The peer may use the MRU to decide its MTU, but this depends on the implementation. The default values are 1360 for L2TP, 1400 for PPTP, and 1492 for PPPoE.

lcp-keepalive yes | no
    Specify whether npppd(8) uses LCP keepalive. The default value is “no” for L2TP and “yes” for PPTP and PPPoE.

lcp-keepalive-interval number
    Specify the interval time between LCP echo requests, in seconds. The default value is 300.

lcp-keepalive-retry-interval number
    Specify the interval time between retrying LCP echo requests without receiving the echo reply from the peer. The value must be specified in seconds. The default value is 60.

lcp-keepalive-max-retries number
    Specify the maximum number of LCP echo retries. If the peer doesn't respond and the number of retries reaches this value, npppd(8) treats the link as dead and closes it. The default value is 3.

lcp-timeout number
    Specify the timeout value for LCP retransmission in seconds. The default value is 3.

lcp-max-configure number
    Specify the maximum number of LCP configure request transmissions. The default value is 10.

lcp-max-terminate number
    Specify the maximum number of LCP terminate request transmissions. The default value is 2.

lcp-max-nak-loop number
    Specify the maximum number of LCP configure NAK loops. The default value is 5.

authentication-method authentication-method ...
    Specify an authentication method:

    pap Password Authentication Protocol.
    chap
        PPP Challenge Handshake Authentication Protocol (RFC 1994).
    mschapv2
        Microsoft PPP CHAP Extensions, Version 2 (RFC 2749).

    mschapv2 is used as the default for PPTP; pap chap mschapv2 is used as the default for other protocols.

ccp-timeout number
    Specify the timeout value for CCP retransmission, in seconds. The default value is 3.

ccp-max-configure number
    Specify the maximum number of CCP configure request transmissions. The default value is 10.

ccp-max-terminate number
    Specify the maximum number of CCP terminate request transmissions. The default value is 2.

ccp-max-nak-loop number
    Specify the maximum number of CCP configure NAK loops. The default value is 5.

ipcp-timeout number
    Specify the timeout value for IPCP retransmission, in seconds. The default value is 3.

ipcp-max-configure number
    Specify the maximum number of IPCP configure request transmissions. The default value is 10.

ipcp-max-terminate number
    Specify the maximum number of IPCP terminate request transmissions. The default value is 2.

ipcp-max-nak-loop number
    Specify the maximum number of IPCP configure NAK loops. The default value is 5.

mppe yes | no | required
    If “yes” is specified, npppd(8) will negotiate to use Microsoft Point-to-Point Encryption (MPPE), and it will continue the PPP even if the negotiation fails. If “required” is specified, npppd(8) will negotiate to use MPPE, and it will not continue the PPP if the negotiation fails. If “no” is specified, npppd(8) will negotiate not to use MPPE and it will refuse to use MPPE. The default value is “required” for PPTP and “yes” for L2TP and PPPoE.

mppe-key-length key-length ...
    Specify key lengths for this configuration. The following key lengths can be used:

    128 128-bit encryption.
    56  56-bit encryption.
    40  40-bit encryption.

mppe-key-state mode ...
    Specify the key change modes that this configuration supports. The following modes can be used:

    stateful
        Stateful mode key changes.
    stateless
        Stateless mode key changes.

idle-timeout number
    Specify the value for the idle timer, in seconds. The link is disconnected if there are no data packets sent or received for more than the amount of the idle-timeout. The default is 0, which disables the idle timer.

tcp-mss-adjust yes | no
    If “yes” is specified, npppd(8) adjusts TCP SYN packets so that the value of TCP maximum segment size (MSS) is less than the value calculated from the link MTU. The default value is “no”.

ingress-filter yes | no
    If “yes” is specified, npppd(8) applies an ingress filter for incoming packets. The ingress filter drops all packets whose source address does not match the address assigned by npppd(8) for the link. The default value is “no”.

pipex yes | no
    Specify whether npppd(8) uses pipex(4). The default is “yes”. The sysctl(8) variable net.pipex.enable should also be enabled to use pipex(4).

debug-dump-pktin protocol ...
    If this option is specified, npppd(8) dumps received packets which match the specified protocol. The following protocols can be specified:

    ip  Internet Protocol (IP)
    lcp Link Configuration Protocol (LCP)
    pap Password Authentication Protocol (PAP)
    chap
        Challenge Handshake Authentication Protocol (CHAP)
    mppe
        Microsoft Point-to-Point Encryption (MPPE)
    ccp Compression Control Protocol (CCP)
    ipcp
        IP Configuration Protocol (IPCP)

debug-dump-pktout protocol ...
    If this option is specified, npppd(8) dumps sent packets which match the specified protocol. See debug-dump-pktin section for protocol.

l2tp-ctrl-in-pktdump yes | no
    Specify whether npppd(8) dumps received L2TP control packets for debugging. The default is “no”.

l2tp-ctrl-out-pktdump yes | no
    Specify whether npppd(8) dumps sent L2TP control packets for debugging. The default is “no”.

l2tp-data-in-pktdump yes | no
    Specify whether npppd(8) dumps received L2TP data packets for debugging. The default is “no”.

l2tp-data-out-pktdump yes | no
    Specify whether npppd(8) dumps sent L2TP data packets for debugging. The default is “no”.

pptp-ctrl-in-pktdump yes | no
    Specify whether npppd(8) dumps received PPTP control packets for debugging. The default is “no”.

pptp-ctrl-out-pktdump yes | no
    Specify whether npppd(8) dumps sent PPTP control packets for debugging. The default is “no”.

pptp-data-in-pktdump yes | no
    Specify whether npppd(8) dumps received PPTP data packets for debugging. The default is “no”.

pptp-data-out-pktdump yes | no
    Specify whether npppd(8) dumps sent PPTP data packets for debugging. The default is “no”.

pppoe-desc-in-pktdump yes | no
    Specify whether npppd(8) dumps received PPPoE discovery packets for debugging. The default is “no”.

pppoe-desc-out-pktdump yes | no
    Specify whether npppd(8) dumps sent PPPoE discovery packets for debugging. The default is “no”.

pppoe-session-in-pktdump yes | no
    Specify whether npppd(8) dumps received PPPoE session packets for debug. The default is “no”.

pppoe-session-out-pktdump yes | no
    Specify whether npppd(8) dumps sent PPPoE session packets for debug. The default is “no”.

IPCP
The ipcp setting is described below:

ipcp name [option ...]

name specifies the name of this ipcp setting. The maximum number of ipcp settings is 8.

The supported options are as follows:

pool-address address-range | address-mask [for dynamic | static]
    Specify the IP address space that is pooled for this IPCP setting. The address space can be specified by address-range (e.g. 192.168.0.2-192.168.0.254) or address-mask (e.g. 192.168.0.0/24) . dynamic means the address space is reserved for dynamic allocation; static means the address space is reserved for static allocation. The default is dynamic. This option can be used multiple times.

dns-servers primary-server-address [secondary-server-address]
    Specify the DNS servers' IP addresses.

nbns-servers primary-server-address [secondary-server-address]
    Specify the NetBIOS name servers' IP addresses.

allow-user-selected-address yes | no
    Specify whether npppd(8) is allowed to assign an address selected by the user. The default is “yes”.

max-session number
    Specify the maximum number of sessions for this ipcp setting. ‘0’ means no limit. The default value is 0.

INTERFACE
The interface setting is described below:

interface ifname address address ipcp ipcp

Use tun(4) or pppx(4) and specify its name to ifname. address is the IP address of this interface, and it is used as the tunnel address to the tunnel peer. ipcp specifies the setting name that is used with this interface. The maximum number of interface settings is 8.

AUTHENTICATION
The authentication setting is described below:

authentication name type type { option ... }

Specify a name for this authentication setting. For type, one of the following can be specified:

local
    Authenticates using local file.
radius
    Authenticates using remote RADIUS servers.

The supported options are as follows:

username-suffix string
    Specify the suffix of the username so that npppd(8) selects this authentication setting only for a user who has the username that matches this suffix pattern.

strip-nt-domain yes | no
    Specify whether npppd(8) removes the NT domain prefix, such as '\\NTDOMAIN\', from the username before contacting the authentication server. The default is “yes”.

strip-atmark-realm yes | no
    Specify whether npppd(8) removes the realm part that begins with an at sign ('@') from the username before contacting the authentication server. The default is “no”.

users-file string
    Specify the path for npppd-users(5) that describes users' account information. The path must be under /etc/npppd/ because npppd(8) is restricted to accessing files only in certain directories.

authentication-server [radius-config]
    This option describes the settings for a RADIUS authentication server.

    address address [port port] [secret secret]
        Specify the IP address and port of the RADIUS server, using shared secret. secret must be less than 127 characters. The default port is 1812 for authentication-server; 1813 for accounting-server. This option can be specified multiple times (maximum 16) in a radius-config.

    timeout number
        Specify the maximum time for waiting for a response, in seconds. The default is 9.

    max-tries number
        Specify the maximum number of retransmissions. The default is 3.

    max-failovers number
        Specify the maximum number of failovers. The default is 1.

accounting-server { radius-config }
    This option describes the settings for a RADIUS accounting server. See authentication-server section for details of radius-config.

user-max-session number
    Specify the maximum number of sessions for each user for this authentication setting.

BIND
bind describes a group of tunnel, authentication, and interface settings so that they are used together.

bind tunnel from tunnel authenticated by authentication to ifname

EXAMPLES
A very simple configuration example is below:

    tunnel L2TP protocol l2tp
    tunnel PPTP protocol pptp
    ipcp IPCP {
        pool-address 10.0.0.2-10.0.0.254
        dns-servers 8.8.8.8
    }
    interface pppx0 address 10.0.0.1 ipcp IPCP
    authentication LOCAL type local {
        users-file "/etc/npppd/npppd-users"
    }
    bind tunnel from L2TP authenticated by LOCAL to pppx0
    bind tunnel from PPTP authenticated by LOCAL to pppx0

Another simple configuration, but with two authentication realms:

    tunnel L2TP protocol l2tp {
        listen on 203.0.113.100
    }
    ipcp IPCP {
        pool-address 10.0.0.2-10.0.0.254
        dns-servers 8.8.8.8
    }
    interface tun0 address 10.0.0.1 ipcp IPCP
    interface tun1 address 10.0.0.1 ipcp IPCP
    authentication RADIUS type radius {
        username-suffix "@example.com"
        authentication-server {
            address 192.168.0.1 secret "hogehoge"
        }
        accounting-server {
            address 192.168.0.1 secret "hogehoge"
        }
    }
    authentication LOCAL type local {
        username-suffix "@local"
        users-file "/etc/npppd/npppd-users"
    }
    bind tunnel from L2TP authenticated by RADIUS to tun0
    bind tunnel from L2TP authenticated by LOCAL to tun1

SEE ALSO
pipex(4), pppx(4), tun(4), npppctl(8), npppd(8), sysctl(8)

BUGS
The current version of npppd(8) does not support adding or removing tunnel settings or changing listener settings (listen address, port and l2tp-ipsec-require).