3Com CoreBuilder 2500, User Manual

Page: 131 / 244

Administering UDP Helper 10-15
Removing an ATM
ARP Cache Entry
To remove an entry from the ATM ARP cache, from the top level of the
Administration Console, enter:
ip atmArpServer arp remove
Enter the ATM address that you want to remove from the cache.
The address is immediately removed from the table.
Flushing the ATM
ARP Cache
To remove all entries from the ATM ARP cache, from the top level of the
Administration Console, enter:
ip atmArpServer arp flush
All ATM ARP cache entries are immediately removed from the table.
Administering
UDP Helper
Use UDP Helper to send User Datagram Protocol (UDP) packets between
routed networks. UDP Helper provides support for UDP services, such as
BOOTP or DHCP (Dynamic Host Configuration Protocol), that rely on the
BOOTP relay agent. For example, by configuring the logical BOOTP port,
you can boot hosts through the router. UDP Helper also provides a relay
agent for DHCP broadcasts. UDP packets that rely on the BOOTP relay
agent are modified and then forwarded through the router.
These ports for UDP services are mentioned in this section on UDP Helper:
■
BOOTP (including DHCP) = 67
■
TIME = 37
■
DNS = 53
With UDP Helper, you can configure the interval of time during which
forwarding can occur between subnetworks. UDP packets are discarded
based on the hop count and seconds value only for BOOTP and DHCP.
Top-Level Menu
system
ethernet
fddi
atm
bridge
➧
ip
ipx
appletalk
snmp
analyzer
script
logout
interface
route
arp
➧
atmArpServer
multicast
udpHelper
routing
icmpRouterDiscovery
ospf
rip
ping
statistics
display
define
remove
➧
arp
display
➧
remove
flush
Top-Level Menu
system
ethernet
fddi
atm
bridge
➧
ip
ipx
appletalk
snmp
analyzer
script
logout
interface
route
arp
➧
atmArpServer
multicast
udpHelper
routing
icmpRouterDiscovery
ospf
rip
ping
statistics
display
define
remove
➧
arp
display
remove
➧
flush