FTOS Configuration Guide for the C-Series - Force10 Networks

Layer 3
C-Series
• 31-Bit Prefix Support on Point-to-Point Ethernet Interfaces: A 31-bit IP prefix length, described in
RFC 3021, allows the use of only two IP addresses on a point-to-point Ethernet interface, conserving
IP address space. Previously, four IP addresses (a /30) or unnumbered interfaces for point-to-point
links were required.
• BFD on Physical, VLAN and LAG Interfaces for OSPF, VRRP, and Static Routes: The FTOS
Bidirectional Forwarding Detection (BFD feature is now available on the C-Series. BFD can be used
to rapidly detect communication failures between two adjacent systems. Scalability and performance
differences exist due to differences in the hardware architecture of each platform. See Chapter 30,
Bidirectional Forwarding Detection, on page 597.
• BGP: The FTOS BGP feature set is now available on the C-Series. Scalability and performance
differences exist due to differences in the hardware architecture of each platform. See Chapter 25,
Border Gateway Protocol (BGP), on page 459.
• BGP 4-Byte AS Numbers: The BGP 4-byte AS number feature, as described in RFC 4893,
extends AS numbers from 2 to 4 bytes. With this extension, the range of AS numbers greatly
expands from 1 to 65535 for 2-byte numbers to 1.0 to 65535.65535 for 4-byte numbers. For
interoperability and compatibility, 4-byte AS number support is advertised through a new BGP
capability (4-BYTE-AS) in the OPEN message.
• BGP “neighbor allowas-in” CLI Command to Allow Prefixes with Own ASN in AS PATH:
The BGP feature set now supports a command to accept prefixes with a router's own AS
number in the AS path. The default behavior is to discard such prefixes since this usually
indicates a loop, however there are cases when this behavior needs to be overridden for
legitimate reasons.
• BGP “neighbor {ip-addr} local-as” CLI for AS Number Transitions: The BGP feature set now
supports a command to configure a second AS number for a particular peer, allowing the
router to appear to be a member of the second AS, in addition to its real AS. It is useful in
cases where the peer cannot change its AS number.
• IP Multicast Enhancements:
• IGMP v1 and v2: Multicast routers use Internet Group Management Protocol (IGMP) to learn
which groups have members on each of their attached physical networks. IGMPv1/v2 is now
supported on the C-Series. See Chapter 29, Internet Group Management Protocol, on page
583.
• PIM-SM: The FTOS implementation of Protocol-Independent Multicast-Sparse Mode
(PIM-SM) is now available on the C-Series. PIM-SM is a multicast protocol in which
multicast receivers explicitly join to receive multicast traffic. The protocol uses a router as the
root or Rendezvous Point (RP) of the share tree distribution tree to distribute multicast traffic
to a multicast group. See Chapter 31, PIM Sparse Mode, on page 627.
Management
FTOS Configuration Guide, version 7.7.1.0 5