If ntp cannot sync because time is too far apart (2)

1) rdate
or
2) ntpdate

Multicast address maps

last three MAC address octets against 224.0.0.1 :
00:03:ba:04:b7:75 becomes 00:03:ba:00:00:01
* Thus, all SunBlade systems will receive the message

This run level starts RARP server

3

To add a static arp entry for helium

arp -s helium 00:c0:f0:31:0c:25

To answer ARP requests on behalf of helium

arp -s helium 00:c0:f0:31:0c:25 pub
* can be used as ARP proxy for PXE+DHCP JumpStart installations

List arp cache for helium

arp helium

arp client asks this question

Who is 192.168.2.99?
* The answer is the MAC address

snoop verbose mode

-v

snoop summary verbose mode

-V

Is eri using 100Mbps or 10Mbps?

ndd /dev/eri link_speed
* 1 : 100
* 0 : 10

Display protocol statistics

netstat -s

Two packet types that are discarded

1) Runt : smaller than 64 byes (caused by collision)
2) Jabber : greater than 1500 bytes (electrical problems)

MTU for a physical Ethernet interface

1500 bytes

To set ethernet address manually (2)

1) eeprom local-mac-address?=true
2) ifconfig eri0 ether xx:xx:xx:xx:xx:xx
* To make stay across reboots, add to init script

Calculate percent collision rate

Num of collisions / num of output packets * 100%
* output of netstat -i

10Mbps and 100Mbps are overloaded when

10Mbps : 5% collision rate
100Mbps : 10% collision rate

Are there collisions?

netstat -i

Gigabit fiber-optic media type

1000BASE-X

Category 3 and Category 5 have this many twists

Category 3 : three twists per foot
Category 5 : three twists per inch

Most popular media type today

10Base-T
* twisted pair

BASE in 100BASE-T stands for

baseband signaling - uses the entire capacity of the cable for one signal