icmp internet control meessage protocol
ip fragments and routes data
csma/cd carrier-sense, multiple access/carrier detect
utp unshielded twisted pair
10baseT 1 UTP
100baseT4 2 UTP
100baseTX 4 UTP
100baseFX 2 strands of multimode fiber
ethernet addr. administered by Xerox, handed out in triplets 8:0:20 for sun
brdcast addr all ff's, or ones in decimal
mtu maximum transfer unit
arp address resolution protocol, used for assmbly of headers
snoop, netstat, ifconfig
snoop broadcast snoop -V mochabomb netstat -i Address field: /etc/inet/hosts netstat -r display routing table for a local system ifconfig le0 show info for my interface
ARP TABLE
Entries: device (le0, etc), IP, Mask, flags, Ether addr
ARP table flags: SPMU: saved, published, mapped for multicast, unresolved
example# arp -a, example# arp -s mochabomb 8:0:20:ab:12:3f add mochabomb perm'ly to table example# arp -s mochabomb 8:0:20:ab:12:3f temp add mochabomb temp'ly to table: 3-4 minutes example# arp -s mochabomb 8:0:20:ab:12:3f pub use for machines that cannot resp'd to arp req's example# arp -d mochabomb delete from table example# arp -f newhosts.txt add from a file of form:hostname ether_addr [temp][pub]
NETWORK INTERFACE CONFIGURATION
init process: /sbin/init /etc/inittab /etc/initd/rootusr /etc/hostname.le0 hostname entry here arp begins with IP, gets ether (target hardware address) rarp begins with known ether, gets IP snoop -v rarp see a rarp request, ON SAME SUBNET in.rarpd rarp daemon, booting machine must be listed in /etc/iniet/hosts & /etc/ethers /sbin/ifconfig -plumb, -a, -unplumb, uses /etc/rc2.d/S72inetsvc & rcS.d/S30rootusr scripts ifconfig le0 up, down turn up, down an interface, take it down before tweaking something ifconfig le0 netmask 255.255.255.0 broadcast + up guess....
The Internet Layer Class
127.0.0.1 loopback address
A 0 first bit 0 allow 1-127 for class A
B 10[000000 to [111111] first two bits are 10, leaving 128-191 for class B
C 110 first 3 bits are 110, leavinbg 192-223 for class C
D 1110 " " leaving 224-239 for multicast
Netmasks Compute the network number 1 bits keep, 0's mask out
A 255.0.0.0, ff:0:0:0
B 255.255.0.0 ff:ff:0:0
C 255.255.255.0 ff:ff:ff:0
Reserved Numbers
129.146.0.0 network number
129.146.255.255 boardcast on that network
0.0.0.0 IP for 'ignorant' systems, need to boot w/o an IP
255.255.255.255 generic broadcast
IPv6: 128 bit address, versus 32 bit
::192.146.52.26 IPv4 in IPv6 format, :: mean zero.