User's Manual

SPEEDLAN 8500 Series Installation and Operation User Guide
IP-Router Setup 8-3
• Default TTL
IP hosts on the Internet send out packets with a default "Time To Live" parameter. If you want
to override the factory default of 64 attempts, specify your new default value here.
• Disable ARP-Cache Aging
Use this option if you want to keep a permanent record of the IP to Ethernet addresses table
for each computer directly connected to an interface on the IDU. This feature is helpful
when used in conjunction with a corporate-wide SNMP monitoring tool to create a
database of all Ethernet-to-IP address combinations on your network. A standard IP router
and the IDU will age their ARP cache entries. It will time out and delete the ARP entries after
a certain specified period (usually 10 minutes). The IDU has the option of not aging
(deleting) any ARP cache entries. This will not normally cause any IP network problems, but
this could result in a large ARP cache table. Since the typical IDU can hold over 10,000
ARP entries, this is not normally a problem.
Add/Direct Button
Click this button to specify the direct routes for each of the interfaces on the IDU. Direct routes are
those that are directly connected to the interfaces. As an example, if Interface 1 is to have subnet
128.146.6.0 connected to it and an IP address of 128.146.6.1 with a subnet mask of
255.255.255.0, an entry in this dialog box should be set up as: IP Address = 128.146.6.1; IP
Mask = FFFFFF00; and Interface = 1.