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
Ping
! 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
Trace
!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.