Perform the following optional tasks to configure PPP authentication:
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Note: The JUNOSe software’s PPP application accepts null usernames during PAP and CHAP authentication. When the PPP application receives an authentication request that includes a null username, PPP passes the request to AAA. To take advantage of this feature, configure your authentication server to support the use of null usernames. |
ppp authentication
- host1(config-if)#ppp authentication pap chap
eap
The router requests the use of PAP as the authentication protocol (because it appears first in the command line). If the peer refuses to use PAP, the router requests the CHAP protocol. If the peer refuses to use CHAP, the router requests the EAP protocol. If the peer refuses to negotiate authentication, the router terminates the PPP session.
- host1(config-if)#ppp authentication virtual-router
boston pap chap
This command is available in static configurations and in profiles.
- host1(config)#interface atm 3/2.100
- host1(config-subif)#ppp authentication eap
- host1(config)#interface atm 3/2.100
- host1(config-subif)#ppp authentication eap
pap
EAP negotiation is attempted first. If PPP receives a NAK from the peer in response to the EAP request, then PAP is attempted. If PAP is also rejected, then PPP terminates the session.
- host1(config)#profile ppptest
- host1(config-profile)#ppp authentication eap
- host1(config)#profile ppptest
- host1(config-profile)#ppp authentication eap
chap pap
In this example, the router first attempts EAP negotiation. If PPP receives a NAK from the peer in response to the EAP request, then the router attempts CHAP negotiation. If PPP receives a NAK from the peer in response to the CHAP request, then the router attempts PAP negotiation. If PAP is also rejected, then PPP terminates the session.
ppp chap-challenge-length
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Caution: Do not decrease the range. Increasing the range is acceptable, provided that you do not lower the minimum to do so. The recommended minimum is 16. A longer challenge and a more unpredictable challenge length provide a higher level of security. |
- host1(config-if)#ppp chap-challenge-length
24 28
ppp max-bad-auth
- host1(config-if)#ppp max-bad-auth 3