User`s guide

64 XSR User’s Guide
General IP Features Chapter 5
Configuring IP
 Ethernet 802.3 support of SNAP and DIX frame format
 Internet Standard Subnetting Procedure (ISSP) - RFC-950
 ARP - dynamic, static, and proxy ARP
 IP subnet zero (always enabled)
 Router ID is always enabled and calculated as the highest non-zero IP
address among all loopback interfaces or the highest non-zero IP
address of existing interfaces (configured interfaces) if no loopback
interfaces are configured. You can configure a loopback address for
the XSR to be used as the Router ID with the
interface loopback
command.
 BOOTP/DHCP relay
 Broadcasting: Directed and UDP broadcast forwarding
 ICMP
– ICMP Router Discovery Protocol
– Destination unreachable message
– Time exceeded message
– Parameter problem message
– Redirect message
– Echo or echo reply message
 TCP
– Window and acknowledgement
– TCP maximum segment size
– Congestion control in TCP/IP
– TCP extensions for high performance
– TCP selective acknowledgement option
 UDP
 Telnet
 SSH
 TFTP
 MTU
– Path MTU discovery protocol: Support for external MTU
discovery (i.e., for data passing through the XSR). An ICMP MTU
size exceeded message is issued if large packets transit the XSR
with the “don't fragment” bit set. These packets are dropped per
RFC-1191. Also, the XSR does not originate MTU discovery, that
is, application data originating in the router.
– Set MTU size per interface