Configuring The Network Control Protocol - Extreme Networks PoS Installation And User Manual

Configuring the Network Control Protocol

The Network Control Protocol is configured on a per-port basis, meaning that different
ports on the same module can be running either the Bridging Control Protocol (BCP) or
the IP Control Protocol (IPCP)—both protocols cannot be configured at the same time
on any port.
Generally, when IPCP is configured on a port, that port must be a member of a single
VLAN. Further, no other ports on this switch can be members of this VLAN, and IP
routing is the only protocol supported on this VLAN. The one exception to this rule is
when Automatic Protection Switching (APS) is enabled. In which case, a single VLAN
may contain two ports configured for IPCP if they are both members of the same APS
group.
For more information about setting up VLANs, see the ExtremeWare Software
User Guide.
BCP establishes and configures a connection for transporting Ethernet MAC frames
across a PPP link. Because BCP carries Ethernet MAC frames, any protocol can be
transported across a BCP connection. In a simplified sense, BCP allows the PoS link to
appear as an Ethernet LAN segment to the rest of the switch, so BCP makes it possible
for LAN services to be extended transparently across SONET wide-area networks.
Therefore, the port can be a member of multiple VLANs, and frames can be either
bridged or routed onto the link.
Generally, most of the switch capabilities provided for Ethernet ports are also available
for PoS ports configured for BCP. One exception is that there are restrictions on which
OC-3 PoS module ports can be bridged together (be configured as members of the same
VLAN). Ports 1 and 2 on the same OC-3 PoS module cannot be bridged together, and
ports 3 and 4 on the same OC-3 PoS module cannot be bridged together—unless they
are members of the same APS group. There are no such restrictions on OC-12 PoS
module ports.
To configure the Network Control Protocol for a specified PPP port, use the following
command:
config ppp [bcp [on | off] | ipcp [on {peer-ipaddress <ipaddress>} | off]]
ports <portlist>
By default, BCP is enabled on all PoS ports. BCP cannot be configured on a port unless
IPCP is off; IPCP cannot be configured on a port unless BCP is off.
Packet Over SONET Module Installation and User Guide
Configuring and Monitoring PPP Functions
3-33