Set both, his and my authentication protocol to protoname. The protocol name can be one of "chap", "pap", or "none". In the latter case, the use of an authentication protocol will be turned off for the named interface. This has the side-effect of clearing the other authentication-related parameters for this interface as well (i.e., system name and authentication secret will be forgotten).
myauthproto = protoname
Same as above, but only for my end of the link. I.e., this is the protocol when remote is authenticator, and I am the peer required to authenticate.
hisauthproto = protoname
Same as above, but only for his end of the link.
myauthname = name
Set my system name for the authentication protocol.
hisauthname = name
Set his system name for the authentication protocol. For CHAP, this will only be used as a hint, causing a warning message if remote did supply a different name. For PAP, it is the name remote must use to authenticate himself (in connection with his secret).
myauthsecret = secret
Set my secret (key, password) for use in the authentication phase. For CHAP, this will be used to compute the response hash value, based on remotes challenge. For PAP, it will be transmitted as plain text together with the system name. Do not forget to quote the secrets from the shell if they contain shell metacharacters (or white space).
myauthkey = secret
Same as above.
hisauthsecret = secret
Same as above, to be used if we are an authenticator and the remote peer needs to authenticate.
hisauthkey = secret
Same as above.
callin
Require remote to authenticate himself only when he is calling in, but not when we are caller. This is required for some peers that do not implement the authentication protocols symmetrically (like Ascend routers, for example).
always
The opposite of callin. Require remote to always authenticate, regardless of which side is placing the call. This is the default, and will not be explicitly displayed in the "list" mode.
norechallenge
Only meaningful with CHAP. Do not re-challenge peer once the initial CHAP handshake was successful. Used to work around broken peer implementations that cannot grok being re-challenged once the connection is up.
rechallenge
With CHAP, send re-challenges at random intervals while the connection is in network phase. (The intervals are currently in the range of 300 through approximately 800 seconds.) This is the default, and will not be explicitly displayed in the "list" mode.
lcp-timeout = timeout-value
Allows to change the value of the LCP restart timer. Values are specified in milliseconds. The value must be between 10 and 20000 ms, defaulting to 3000 ms.
enable-vj
Enable negotiation of Van Jacobsen header compression. (Enabled by default.)
disable-vj
Disable negotiation of Van Jacobsen header compression.
enable-ipv6
Enable negotiation of the IPv6 network control protocol. (Enabled by default if the kernel has IPv6 enabled.)
disable-ipv6
Disable negotiation of the IPv6 network control protocol. Since every IPv4 interface in an IPv6-enabled kernel automatically gets an IPv6 address assigned, this option provides for a way to administratively prevent the link from attempting to negotiate IPv6. Note that initialization of an IPv6 interface causes a multicast packet to be sent, which can cause unwanted traffic costs (for dial-on-demand interfaces).