User guide

Configuring DHCP/BOOTP Relay
ExtremeWare 7.2e Installation and User Guide 223
disable icmp time-exceeded {vlan <vlan name>}
To enable or disable the generation of an ICMP timestamp response on one or all VLANs, use the
following commands:
enable icmp timestamp {vlan <vlan name>}
disable icmp timestamp {vlan <vlan name>}
To enable or disable the generation of ICMP unreachable messages on one or all VLANs, use the
following commands:
enable icmp unreachables {vlan <vlan name>}
disable icmp unreachables {vlan <vlan name>}
To enable or disable the modification of route table information when an ICMP redirect message is
received, use the following commands:
enable icmp useredirects
disable icmp useredirects
To reset all of the ICMP settings to the default values, use the following command:
unconfigure icmp
For ICMP packets that are typically routed, you can apply access lists to restrict forwarding behavior.
Access lists are described in Chapter 9.
Configuring DHCP/BOOTP Relay
Once IP unicast routing is configured, you can configure the switch to forward Dynamic Host
Configuration Protocol (DHCP) or BOOTP requests coming from clients on subnets being serviced by
the switch and going to hosts on different subnets. This feature can be used in various applications,
including DHCP services between Windows NT servers and clients running Windows 95. To configure
the relay function, follow these steps:
1 Configure VLANs and IP unicast routing.
2 Enable the DHCP or BOOTP relay function, using the following command:
enable bootprelay
3 Configure the addresses to which DHCP or BOOTP requests should be directed, using the following
command:
configure bootprelay add <ip address>
To delete a BOOTP relay entry, use the following command:
configure bootprelay delete [<ip address> | all]
Configuring the DHCP Relay Agent Option (Option 82)
After configuring and enabling the DHCP/BOOTP relay feature, you can enable the DHCP relay agent
option feature. This feature inserts a piece of information, called option 82, into any DHCP request