Ipcp Lockout And Local Ip Address Pool Restoration; Ipcp Negotiation With Optional Peer Ip Address - Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual

JunosE 11.2.x Link Layer Configuration Guide

IPCP Lockout and Local IP Address Pool Restoration

IPCP Negotiation with Optional Peer IP Address

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If B-RAS sends a NAK, it prompts the options, until max configure-nak is exceeded
If B-RAS sends an ACK, it ignores the options and brings up this link
The CPE NAKs or rejects the prompted options
This behavior is non-compliant with RFC because a configure-rej or a configure-nak
must be sent only in response to a configure-req
You can configure the router to terminate invalid IPv4 subscribers and return the unused
IPv4 addresses to the local address pool. When Internet Protocol version 6 Control
Protocol (IPv6CP) is negotiated, the router waits for 10 seconds for Internet Protocol
Control Protocol (IPCP) negotiation. If IPCP is not negotiated in 10 seconds, the interface
blocks IPv4 over Network Control Protocol (NCP) packets and the IP address is returned
to the local address pool. The subscribers must then reconnect to negotiate IPCP again.
The router assigns IPv4 and IPv6 addresses for a PPP subscriber after authentication in
the following ways:
RADIUS returns a valid IP address or a IPv6 prefix
The configured local address pool returns a valid IP address
The subscriber can negotiate IPv4 addresses, IPv6 addresses, or both. After an IPv6
address is negotiated for an IPCP service, the PPP application waits for the negotiation
of IPv4 address and then returns the assigned unused addresses to the local pool. By
default, this feature is disabled. To enable the feature, issue the ppp ipcp lockout
command from Interface Configuration, Subinterface Configuration, or Profile
Configuration modes. This command terminates the invalid subscriber entry and prevents
additional IPCP negotiations. When IPv6CP is active and if the IPCP must close, the router
does not terminate PPP and Link Control Protocol (LCP) and does not return the address
to the pool. In this case, AAA uses the assigned IP address and reassigns the same address
when IPCP is negotiated again.
During normal operation for an IPCP negotiation, if the client does not request a specific
IP address, the server sends an IP address obtained from RADIUS or from the local address
pool.
If the client seeks a specific IP address, on receiving a NAK from the server, it sends a
confReq message without specifying the IP address option. In this case, even though the
server sends an IPCP confAck message , the server terminates the client because the
server requires an IP address from the client.
You can use the ppp peer-ip-address-optional command in Global Configuration mode
to specify that the peer IP address is optional. By default, this command is disabled. This
feature also supports high availability (HA) and unified in-service software upgrade
(Unified ISSU).
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