IOS Tips

-Reset port gi1/0/1 to default:
# conf t
(config) # default interface gi1/0/1

-Reset ports 1-48 to default:
# conf t
(config)# default int range gi1/0/1-48

-Edit ports 1-48 at the same time
# conf t
(config)# int range gi1/0/1-48
(config-if)# <enter config change>

-Apply a config change to a non-contiguous range of ports
# conf t
(config) # int range gi1/0/1 – 5 , gi1/0/10 – 15
(config-if)# <enter config change>

-Do multiple steps in a single command when provisioning a port for an end-device
# conf t
(config)# int gi1/0/1
(config-if)# switchport host
   sets switch port mode to access + enables spanning tree Port Fast + disables channel grouping.

-Use macros to run a script by entering a single command AND use variables
 Create the macro
# conf t
(config)# macro name SetTrunk
description TRUNK PORT
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan $NATIVE
switchport trunk allowed vlan $ALLOWED
mls qos trust dscp
no shut
 Now apply the macro to a port you want to create as a trunk, set the native VLAN to 123 and define all VLANs as being allowed
# conf t
(config)# int gi1/0/1
(config-if)# macro apply SetTrunk $NATIVE 123 $ALLOWED all

-Show all interfaces and the CRC count for each
# show interface | i protocol|CRC
GigabitEthernet1/0/5 is up, line protocol is up (connected)
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

-Find what ports are not currently connected
# sh int status | i notconnect

-Show what ports are down due to BPDUguard
# sh int status | i err
# show log | i BPDU|bpdu
%SPANTREE-2-BLOCK_BPDUGUARD: Received BPDU on port GigabitEthernet1/0/16 with BPDU Guard enabled. Disabling port.
%PM-4-ERR_DISABLE: bpduguard error detected on Gi1/0/16, putting Gi1/0/16 in err-disable state

-Delete a directory
# del /force /recursive directory_name

-For all switches in a stack, define both a primary AND a secondary boot image
# all flash:c3750-ipbasek9-mz.122-55.SE8.bin;flash:c3750-ipbasek9-mz.122-55.SE7.bin

-Get extended details about the packets crossing an interface
#show interfaces f2/0/17 controller
     Transmit FastEthernet2/0/17              Receive
     18971276 Bytes                         33189871 Bytes
        14754 Unicast frames                   59339 Unicast frames
        43389 Multicast frames                  3440 Multicast frames
        99892 Broadcast frames                 43925 Broadcast frames
            0 Too old frames                29986661 Unicast bytes
            0 Deferred frames                 346082 Multicast bytes
            0 MTU exceeded frames            2855260 Broadcast bytes
            0 1 collision frames                   0 Alignment errors
            0 2 collision frames                   0 FCS errors
            0 3 collision frames                   0 Oversize frames
            0 4 collision frames                  17 Undersize frames
            0 5 collision frames                   0 Collision fragments
            0 6 collision frames
            0 7 collision frames               46501 Minimum size frames
            0 8 collision frames                7813 65 to 127 byte frames
            0 9 collision frames                1613 128 to 255 byte frames
            0 10 collision frames               2114 256 to 511 byte frames
            0 11 collision frames              47218 512 to 1023 byte frames
            0 12 collision frames               1462 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames
            0 14 collision frames                  0 Pause frames
            0 15 collision frames
            0 Excessive collisions                 0 Symbol error frames
            0 Late collisions                      0 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large
            0 Excess defer frames                  0 Invalid frames, too small
       112850 64 byte frames                       0 Valid frames, too small
         6718 127 byte frames
        20771 255 byte frames                      0 Too old frames
        16109 511 byte frames                      0 Valid oversize frames
         1445 1023 byte frames                     0 System FCS error frames
          142 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames
            0 Good (1 coll) frames
            0 Good (>1 coll) frames

-Show receive and transmit utilization for all ports
0# sh controllers utilization
Port       Receive Utilization  Transmit Utilization
Fa2/0/1            0                    0
Fa2/0/2            0                    0
Fa2/0/3            0                    0
Fa2/0/4            0                    0
Fa2/0/5            0                    0

-Modify an access-list that is referenced with a class-map and policy-map (basically, you need to delete from the top down and rebuild from the bottom up):
Steps explained
# conf t
   remove the policy within the policy map that references the class-map that references the access-list (access-group)
   Remove the class-map that references the access-list (access-group)
   do a no access-list to remove the ACL
   Enter in the ACL statements
   Enter in the class-map statements
   change to policy-map
   Enter in the policy-map statements
Steps performed
   For this setup we’ll use this configuration
# conf t
(config)# policy-map MARK-LAN-DSCP
(config-pmap)# class EF-105-CLASS
(config-pmap-c)# set dscp ef
(config-pmap-c)# class-map match-any EF-105-CLASS
(config-cmap)# match access-group 105
(config-cmap)# exit
(config)# access-list 105 permit ip host any
GOAL: To edit access-list 105 and change one of the source IP’s without the switch choking on itself
# conf t
(config)# policy-map MARK-LAN-DSCP
(config-pmap)# no class EF-105-CLASS
(config-pmap) # exit
(config)# no class-map match-any EF-105-CLASS
(config)# no access-list 105
(config)# access-list 105 permit ip host any
(config)# access-list 105 permit ip host any
(config)# class-map match-any EF-105-CLASS
(config-cmap)# match access-group 105
(config-cmap)# exit
(config)# policy-map MARK-LAN-DSCP
(config-pmap)# class EF-105-CLASS
(config-pmap-c)# set dscp ef
(config-pmap-c)# exit
(config-pmap)# exit
(config)# exit
# wr

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