Reference Guide

1390 | SONET
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Syntax
loopback {internal | line}
To delete a loopback setting, use the no loopback {internal | line} command.
Parameters
Defaults
Not configured.
Command Modes
INTERFACE
Usage
Information
Use the show config command in the INTERFACE mode to determine if the loopback command was
configured.
Related
Commands
ppp authentication
e
Enable Challenge-Handshake Authentication Protocol (CHAP) and/or Password Authentication
Protocol (PAP) authentication on the interface.
Syntax
ppp authentication {chap | chap pap | pap | pap chap}
To remove all PPP authentication, enter no ppp authenticate.
Parameters
Defaults
Not configured.
Command Modes
INTERFACE
Usage
Information
Once you configure this command, the remote device must prove its identity before the FTOS sends
traffic.
The two authentication types differ slightly:
• With CHAP authentication, the E-Series sends a challenge to the remote device, which must
encrypt the response with a shared value and return it to the E-Series with a username. The
E-Series checks the local database for a match on the shared value and username.
• With PAP authentication, the remote device must send a username/password set which the FTOS
checks against the local database. PAP passwords are sent as “clear text” and could be intercepted
and used.
internal Enter the keyword internal to test the physical interface by sending incoming traffic
back through the interface.
line Enter the keyword line to test connectivity to the network by sending incoming traffic
back to the network.
show config
Display the interface configuration.
chap Enter the keyword chap to enable CHAP authentication only.
chap pap Enter the keywords chap pap to enable CHAP on one side and PAP on the other.
pap Enter the keyword pap to enable PAP authentication only.
pap chap Enter the keywords pap chap to enable PAP on one side and CHAP on the other
side.