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
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
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.