Show commands

May 24 2009   11:35AM GMT

How to Determine the Serial Number of Supervisor Engine installed in a Cisco Catalyst 6500 Switch

Posted by: Yasir Irfan
Cisco Tips, Cisco Catalyst 6500 Switch, Cisco IOS Commands, Cisco Supervisor Engine, show idprom, Show commands

Imagine you have a Cisco Catalyst 6500 Switch, you were asked to figure out the Serial number for the Supervisor Engine Installed in your Cisco Catalyst 6500 Switch , it can done by using issuing the following command  “show idprom module” as shown in the below example.

 

ITKE-DAC-6500-BB01#show idprom module 7

IDPROM for module #7

  (FRU is ‘Supervisor Engine 720′)

  OEM String = ‘Cisco Systems’

  Product Number = ‘WS-SUP720-3B’

  Serial Number = ‘SAD084608JG’

  Manufacturing Assembly Number = ‘73-9740-01′

  Manufacturing Assembly Revision = ‘A0′

  Hardware Revision = 4.0

  Current supplied (+) or consumed (-) = -4.50A

ITKE-DAC-6500-BB01#

Dec 2 2008   7:30AM GMT

How to configure SPAN(Switched Port Analyzer ) feature in a Cisco Catalyst Switch

Posted by: Yasir Irfan
Switches, Cisco, Switching, Cisco IOS, Wireshark, Cisco 2960, Cisco 2950, Cisco 6500, Cisco Tips, Cisco 3560, Cisco 3745, Cisco Learning, Cisco 3750-E, Cisco 3560-E, Network Troubleshooting, Show commands, Cisco 6500 Series Catalyst Switch, Cisco 6503, Cisco Catalyst 6503-E Switch, Cisco Catalyst 6506-E Switch, Cisco Catalyst 6509-V-E Switch, Cisco Catalyst 6509-E Switch, Cisco Catalyst 6513 Switch, SPAN, Sniifer

It’s quite important for Network Engineers and an essential network troubleshooting technique to utilize the ability of Cisco Catalyst Switches to mirror the traffic and send it to a sniffer for analysis. All Cisco Catalyst Switches support the Switched Port Analyzer (SPAN) feature. The SPAN copies traffic from the specified interface or VLANs and mirrors this traffic to a specified destination interface (SPAN interface).  Then you can connect the PC with a sniffing tool (Wireshark) installed on the destination SPAN interface to capture all the mirrored traffic.Let’s see how to configure the SPAN in Cisco Catalyst Switches.  To enable the switch SPAN mirroring feature configure the following on the catalyst switch: Configuration Example - Monitoring traffic from a specific interfaceITKEAS01#configure tITKEAS01(config) monitor session 1 source interface gigabitEthernet 0/5

ITKEAS01(config)#monitor session 1 destination interface gigabitEthernet 0/10 

The  above configuration will capture all traffic from interface gigabitEthernet 0/5  and send it to SPAN port interface gigabitEthernet 0/10 

Configuration Example - Monitoring an entire VLAN traffic
ITKEAS01(config)#monitor session 1 source vlan 100
ITKEAS01(config) monitor session 1 destination interface gigabitEthernet 0/10 The  above configuration will capture all traffic of VLAN 100 and send it to SPAN port interface gigabitEthernet 0/10

Use  show monitor session 1 to verify your configuration.

Sep 3 2008   10:13AM GMT

Enhanced Show interfaces commands in a Cisco Routers & Cisco Catalyst Switches.

Posted by: Yasir Irfan
Switches, Routers, Cisco 2950, Cisco 6500, Cisco Tips, Cisco 3745, Show commands, IOS commands

Enhanced Show interfaces commands in a Cisco Routers & Cisco Catalyst Switches.

I was amazed to see many options available with “show interfaces commands which are undocumented, most of these commands are available in IOS release 12.2(44) (may be available with earlier versions, if so do comment).

Some of the undocumented commands are as follows
1) Show interfaces description displays interfaces names, Line and Line protocol status and interface description. Extremely useful to know the status of interfaces which are up or down.
2) Show interfaces counters protocol status displays the L3 protocols active on each interface.
3) Show interfaces summary displays the state of various interface queues and related drop counters in a good tabular format.
4) Show interfaces accounting displays per-protocol in/out counters.

Here are few sample outputs:

Sample Output from Cisco 3745 Router
MBGF-DAC-3745R01#sho interfaces description
Interface                      Status         Protocol Description
Fa0/0                           up             up       WAN connection THru. Bayanat
Fa0/1                            up             up       Connected to LAN
Tu0                                up             up      
MBGF-DAC-3745R01#

Sample output for Cisco 3560 Switch
MBGF-DAC-3560-AS02#sho interfaces description
Interface               Status         Protocol       Description
Vl1                               up             up      
Vl50                            up             up      
Gi0/1                          up             up      
Gi0/2                          up             up      
Gi0/3                          up             up      
Gi0/4                          up             up      
Gi0/5                          up             up      
Gi0/6                          up             up      
Gi0/7                          down           down    
…… 
Gi0/25                         up             up                con2 Khalid
Gi0/26                         down           down    
Gi0/27                         down           down    
Gi0/40                         up             up             CON2-DCAP-50
Gi0/41                         up             up      
Gi0/42                         up             up      
Gi0/43                         up             up  

Gi0/52                         up             up      
MBGF-DAC-3560-AS02#
MBGF-DAC-3745R01#show interfaces counters protocol status
Protocols allocated:
 FastEthernet0/0: Other, IP, DEC MOP, ARP, CDP
 FastEthernet0/1: Other, IP
 Tunnel 0:        Other, IP
 
MBGF-DAC-3560-AS02#sho interfaces counters protocol status
Protocols allocated:
 Vlan1: Other, IP, ARP
 Vlan50: Other, IP, ARP
 GigabitEthernet0/1: Other, IP, Spanning Tree, CDP
 GigabitEthernet0/2: Other, IP, Spanning Tree, CDP
 GigabitEthernet0/3: Other, IP, Spanning Tree, CDP
 GigabitEthernet0/4: Other, IP, Spanning Tree, CDP
 GigabitEthernet0/5: Other, IP, Spanning Tree, CDP
 GigabitEthernet0/6: Other, IP, Spanning Tree, CDP
Allocation failures: 0
MBGF-DAC-3560-AS02#
MBGF-DAC-3745R01#sho interfaces summary

 *: interface is up
 IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
 OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
 RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
 TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
 TRTL: throttle count

  Interface                    IHQ   IQD  OHQ   OQD  RXBS RXPS  TXBS TXPS TRTL
————————————————————————
* FastEthernet0/0          0     0    0     0 10803000  1233 1511000  873    0
* FastEthernet0/1          0     0    0     0 1379000  876 10614000  1237    0
* Tunnel0                         0     0    0     0 10664000  1233 1414000  873    0
NOTE:No separate counters are maintained for subinterfaces
     Hence Details of subinterface are not shown
MBGF-DAC-3745R01#

MBGF-DAC-3560-AS02#sho interfaces summary

 *: interface is up
 IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
 OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
 RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
 TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
 TRTL: throttle count

  Interface               IHQ   IQD  OHQ   OQD  RXBS RXPS  TXBS TXPS TRTL
————————————————————————-
* Vlan1                                0     0    0     0     0    0     0    0    0
* Vlan50                             0     0    0     0  1000    2  1000    2    0
* GigabitEthernet0/1       0     0    0 54684     0    0  2000    3    0
* GigabitEthernet0/2       0     0    0 54675     0    0  3000    3    0
* GigabitEthernet0/3       0     0    0 54675     0    0  2000    3    0
* GigabitEthernet0/4       0     0    0 54688     0    0  2000    3    0
* GigabitEthernet0/5       0     0    0 54664     0    0  2000    3    0
* GigabitEthernet0/6       0     0    0 54663     0    0  2000    3    0
………
  GigabitEthernet0/46      0     0    0   274     0    0     0    0    0
* GigabitEthernet0/47      0     0    0  5036     0    0  2000    3    0
* GigabitEthernet0/48      0     0    0 16702     0    0  3000    3    0
* GigabitEthernet0/49      0     0    0     0 10000   18     0    0    0
 * GigabitEthernet0/52      3     0    0     0 389000  208 1652000  223    0
MBGF-DAC-3560-AS02#

MBGF-DAC-3745R01#show interfaces accounting
FastEthernet0/0 WAN connection THru. Bayanat
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                   Other          0          0      78271    4696260
                      IP  228129752  604147266  238404086 3496449051
                 DEC MOP          0          0       1304     100408
                     ARP      61201    3672060        230      13800
FastEthernet0/1 Connected to LAN
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                   Other      13048    5206152      78271    4696260
                      IP  239500045 3032167184  230865599 2990242469
                 DEC MOP          0          0       1304     100408
                     ARP      97797    5867820      75355    4521300
Tunnel0
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                      IP  228294310 1722638248  238403420  156253505
MBGF-DAC-3745R01#

Aug 5 2008   6:52AM GMT

Show Commands in Cisco Routers and Layer 3 Switches(Most commonly used)Series -2

Posted by: Yasir Irfan
Networking, Switches, Cisco, Routers, Cisco Tips, Cisco 3560, Show commands, IOS commands, Router Troubleshooting

In my previous post I tried to cover some of the show commands which are quite useful to any Network Administrator to manage the day to day activities. In this post I will try to complete the set of 10 show commands I selected.

1. Show access-list

The show access-list displays the contents of each access list. It is very helpful in troubleshooting filtering issues.  But this command does not show you where each access list is applied.

2. Show ip interface

The show ip interface command displays very useful information about configuration & status of IP protocols, it services on all available interfaces.  The show ip interface command also provides information about the access lists applied in all interfaces and also in which direction. This kind of information is not shown by the “show access-list” command. Even the “show run” command displays the information about access lists.

3. Show cdp neighbor detail

The show cdp neighbor detail command displays the information about all the neighboring devices connected with most valuable information like IP addresses, platform and host names. The show cdp neighbor details is very helpful to troubleshoot the connectivity issued and can also used to find out how devices are connected to each other especially when there is nor proper network layouts.

4. Show version

The show version command displays the detail information about the IOS installed, file named used for the IOS along with the version of IOS, router configuration register, model of the router , when the router was rebooted last time of course the amount  of RAM and flash.

 5. Show flash

The show flash command displays the contents of the flash and the size of the IOS files and the size of the flash and freely available flash. It’s useful whenever the IOS is upgraded to check the amount of free space available.  

Aug 2 2008   6:43AM GMT

Show Commands in Cisco Routers and Layer 3 Switches(Most commonly used)Series -1

Posted by: Yasir Irfan
Switches, Cisco, Routers, Cisco 2950, Cisco 6500, Cisco Tips, Cisco 3560, ASA/PIX, Cisco 525, PIX 525, Cisco 3745, Cisco 3750-E, Cisco 3560-E, Show commands, IOS commands, Router Troubleshooting

Some of the widely used commands in Cisco routers are just simple unavoidable, among the most commonly used commands in a Cisco Routers are “show” commands. These commands are essential to Network Administrators. Here is a list of those commands. I will try to cover this in two series. Here is the first series

1. Show running-configuration

The show running-configuration command shows the complete current running configuration in a router, firewall or a switch. Using show running-configuration command a network administrator can troubleshoot almost all issues related routing, filtering secure access, encapsulation, interface mismatch, and many more issues.

2. Show startup-configuration

The show startup-configuration command shows the configuration that is saved on the NVRAM. It is helpful in knowing the configuration that will be applied the next time the routers is reloaded. And also this command is useful in knowing the configuration that was loaded at the start-up of the router before making changes to it.  3. Show Interface

The Show interface command shows the status and statistics of the router interfaces. The show interface command is useful to troubleshoot the routing and link issues. The show interface command output includes interface status, interface IP address and subnet mask, protocol status on an interface, encapsulation type, bandwidth, utilization and much more information related to interface operation.

4. Show ip route

The show ip route command shows the routers routing table.  Routing protocols used and what networks these protocols are advertised. The show ip route command is used to troubleshoot routing problems.

5. Show ip protocols

The show ip protocols displays the routing protocols used in a router and the networks to which these protocols are advertised. It also shows the sources of the routing updates received and very helpful to troubleshoot routing issues.