MonkeyBrains.net/~rudy/example Random examples

  Port Id'ing 

Cacti is a great SNMP tool for monitoring traffic on your switches. Sometimes switches are moved around, things are plugged in, and we don't know what is plugged into which port on our switches. here is a real simple HOW-TO to identifiy what is plugged into which port.

  1. Login to cluster commander (goat).
  2. Next we want to know the cluster members and their 'cluster number' (show in the first column). 
    goat#show cluster members
                                        |---Upstream---|
SN MAC Address    Name   PortIf FEC Hops   SN PortIf  FEC  State
0  0017.9468.1110 goat               0                     Up   (Cmdr)
1  000f.8f54.1110 horse Gi0/1        1     0  Gi0/21       Up
2  00b0.6476.6140 gato               1                     Down
3  0006.d71b.1110 dog   Gi0/1        1     0  Gi0/22       Up
4  0001.9609.a580 chick              255                   Up
  3. Traffic is high on port FastEthernet 0/5 in horse -- Here is what you would do to find the machine on that port: 
    goat#rcommand 1
horse#show mac-address-table interface FastEthernet 0/5
         Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
  3    0030.4858.4ea4    DYNAMIC     Fa0/5 
horse#show vlan

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/13, Fa0/15, etc...
2    SimpleStar                       active    Gi0/2
3    dovetail                         active    Fa0/2, Fa0/3, Fa0/4, Fa0/5, etc...
101  windows1                         active    Fa0/17
    ... you would notice that port 5 is part of the VLAN 3. You run the 'show vlan' command and see that is an internal vlan. Since it is not doing external bandwidth, we don't really care -- in this case -- what machine is plugged into that port.
  4. To find chick FE port 18, you would first find the mac address(es) on that port. 
    goat#rcommand 4
chick#show mac-address-table interface FastEthernet 0/18
Non-static Address Table:
Destination Address  Address Type  VLAN  Destination Port
-------------------  ------------  ----  --------------------
0030.4856.830c       Dynamic          1  FastEthernet0/18
    Next, you would want to log onto the router as that machine is definitely in the same 'network' as all the machines on the LAN. 
    (root@coconut) 114> arp -a | grep '00.30.48.56.83.0c'
arzy.net (208.69.42.43) at 00:30:48:56:83:0c on em0 [ethernet]
    There you have it! Rudy

    This data is completely accurate.