Chapter Ten

IP addressing and routing

All nodes use a 32 bit addressing scheme
Router interfaces also have an address, the must be configured to run the internet protocol
Ping and Trace Command to verify connection
Each comapany considered a single network

Functions for IP and Subnet Masks

1)  Enable system to process the reseipt and transmission of packets
2)  Specify devices logical addressing.
3)  Apecify the range of addresses that share a cable with a device

Direct Broadcasts are seen by every host on a subnet
Flooded broadcasts everyone on network gets it

IP addressing configuration

ip address [address] [default subnet mask]  establishes logical address of router interface
ip host [name] [address(s)]  makes static name to address routing entry in table
no ip domain-lookup   turns off bame-to-address translation

Verifying Address Configuration

telnet - must complete test layers 1-7 layers
ping - uses ICMP internet layer, sends out echo request
trace - uses ttl value

If you can't telnet but can ping, problem lies in upper layer

Command Output

Show Host
host  names of learned hosts
flag  description of information that was learned and its current status
perm  manually configured in host table
temp Acquired from DNS use
ok  entry is current
ex  entry is aged out, expried
age  time measured in hours since software has checked entry
type  protocol field
address(es)  logical addressses associated with host name

!    Successful receipt of echo reply
.    Timed out waiting for datagram reply
U   Destination unreachable error
C   Congestion-experienced packet
I     Ping interrupted (e.g. Ctrl-Shift-6 X)
?    Packet type unknown
&   Paccket TTL exceeded

!H    The probe was received by the router, but not forwarded, usually due to an access list.
P      The protocol was unreachable.
N     The network was unreachable.
U     The port was unreachable.
*      Time out.