User`s guide

XSR Users Guide 65
Chapter 5 General IP Features
Configuring IP
IP Interface
Numbered interfaces
Un-numbered interfaces on point to point links
NBMA support
- Point to multipoint networks
- Fully meshed networks
Secondary IP
Troubleshooting Tools
Ping
Traceroute
IP Routing
RIP
Triggered-on-Demand RIP updates
OSPF
Static routes
Default network
CIDR (IP classless)
Network Address Translation (NAT)
Virtual Router Redundancy Protocol (VRRP): RFC-2338 and
Definitions of Managed Objects for the Virtual Router Redundancy
Protocol: RFC-2787
ARP and Proxy ARP
ARP (Address Resolution Protocol) is a link-level protocol which provides a
mapping between the two different forms of addresses: 32-bit IP addresses
and hardware addresses used by the data link. The protocol dynamically
keeps entries in the ARP Table and can accept statically configured entries
according to RFC-826.
The
arp command adds or deletes permanent entries to the ARP Table while
the
arp-timeout command sets the duration for an ARP entry to stay in the
ARP table before expiring.
Proxy ARP, always enabled on the XSR, lets the XSR answer ARP requests on
one network for a host on another network. The router acts as a proxy agent
for the destination host, relaying packets to it from other hosts, as defined by
RFC-1027. It is configured with the
ip proxy-arp command.