Adding An Ip Address - Foundry Networks Switch and Router Installation And Configuration Manual

Configuring POS Interfaces
To configure a Layer 3 POS interface, you need to add an IP address to the interface. Each POS interface also
has the following additional parameters. The parameters have factory defaults but you can modify the values if
needed for your network.
NOTE: To configure a Layer POS interface for remote bridging, see "Configuring POS for Layer 2 Switching" on
page 6-11.
• Encapsulation type – You can configure a POS interface to use PPP (Point-to-Point Protocol), HDLC (High-
Level Data Link Control), or Frame Relay encapsulation. The default is PPP.
• Clock source – You can configure a POS interface to use the POS module's internal clock or use the network
as the clock source. By default, Foundry POS interfaces use the network as the clock source.
• Loopback path – During startup, the POS module tests each POS interface by performing loopback tests.
You can configure the path used by the loopback test. The path can consist of the POS module's interface
circuitry alone, or can include both the local and remote POS interfaces. The loopback path and tests are
disabled by default.
• Bandwidth – You can change a 622 Mbps port to run at 155 Mbps if needed.
• MTU (Maximum Transmission Unit) – You can specify the maximum IP packet size or SONET/SDH frame
size. The size can be from 60 – 4470 bytes. The default is 4470 bytes.
• Frame type – You can configure a Foundry POS interface to transmit and receive SDH (Synchronous Digital
Hierarchy) frames or SONET (Synchronous Optical Network) frames. The default is SONET.
• Keepalive messages – You can disable or reenable a POS interface to send PPP or HDLC keepalive
messages to the POS interface at the other end of the link. Keepalive messages are enabled by default.
• ATM scramble mode – You can enable or disable scrambling of the Synchronous Payload Envelope (SPE).
When you enable scrambling, the data in the SONET packet is scrambled for security. ATM SPE scrambling
is disabled by default.
• CRC (Cyclic Redundancy Check) – You can specify the length of the CRC field in each packet sent by the
POS interface. The default length is 32 bits. You can change the length to 16 bits.
• SONET overhead Flags – You can change the following values in the SONET frame header:
• c2 – Path signal identifier, which identifies the payload content type. The default is 0xCF, which specifies
PPP or HDLC.
• j0 – Section trace byte, which can be configured to allow interoperability with various other types of SDH
devices. The default value is 0xCC.
• j1 – Bits 5 and 6 of the payload pointer byte, which indicates the frame type. The default is 0x00
(SONET). You can change this value to 0x02 (SDH).
To configure POS interface parameters, use the procedures in the following sections.

Adding an IP Address

You can add up to 24 IP sub-net interfaces to each POS interface.
USING THE CLI
To add an IP address to POS interface 2/1, enter the following commands:
BigIron(config)# interface pos 2/1
BigIron(config-posif-2/1)# ip address 209.157.22.26/24
BigIron(config-posif-2/1)# write memory
Syntax: [no] ip address <ip-addr> <ip-mask> [secondary]
or
December 2000
Using Packet Over SONET (POS) Modules
6 - 5