How to Cisco

Password Recovery Procedure

ROMmon

confreg 0x2142 (at the rommon 1> prompt)
reset

Ctrl-c
enable
copy startup-config running-config

Issue the show running-config command. This procedure is likely to leave your switch virtual interface in a shutdown state.

configure terminal
config-register 0x2102
do show version
enable secret cisco
Ctrl-z or end
write memory
reload

Source

Catalyst

flash_init
load_helper
dir flash:
rename flash:config.text flash:config.text.old
boot

Ctrl-c
enable
rename flash:config.text.old flash:config.text
copy flash:config.text running-config

Issue the show running-config command. This procedure is likely to leave your switch virtual interface in a shutdown state.

configure terminal
enable secret cisco
Ctrl-z or end
write memory
reload

Source

Upgrade Secondary ROMmon CLI

enable
upgrade rom-monitor file flash:/<file>

Source

Upgrade IOS tar file

dir flash:
delete flash:c2950-i6q4l2-mz.121-22.EA1.bin
delete /force /recursive flash:<directory name>

archive tar /xtract tftp://10.10.10.3/c2950-i6q4l2-tar.121-22.EA1.tar flash:
verify flash:c2950-i6q4l2-mz.121-22.EA1.bin

wr mem
reload

SSH

Change SSH port

R1(config)# ip ssh port 2009 rotary 1
R1(config)# line vty 0 4
R1(config-line)# rotary 1

Set SSH

ip domain-name rtp.cisco.com

show crypto key mypubkey rsa
crypto key generate rsa

ip ssh version 2
ip ssh time-out 60
ip ssh authentication-retries 2

VPN

Debugging

debug crypto isakmp
show crypto isakmp sa <vrf> [detail]
show crypto isakmp peer <ip-addr>
sh crypto isakmp peers detail
sh crypto isakmp sa detail
sh crypto ipsec sa detail
sh crypto ipsec sa peer x.x.x.x

• https://supportforums.cisco.com/community/netpro/security/vpn/blog/2011/05/02/ipsec-important-debugging-and-logging

crypto isakmp

• http://www.cisco.com/en/US/products/ps6017/products_command_reference_chapter09186a00808ab59a.html

Site to Site

Reset VPN

clear crypto sa peer x.x.x.x
show crypto isakmp sa
clear crypto isakmp 1338

Debug

terminal monitor
debug crypto isakmp error
debug crypto ipsec error
debug crypto engine error
debug crypto routing 

SSL VPN

• VPN modul
• Tutorials
• http://www.firewall.cx/cisco-technical-knowledgebase/cisco-routers/904-cisco-router-anyconnect-webvpn.html

QoS

Legacy QoS Command Deprecation

Source

IOS 15

Radius server

aaa group server radius RADIUS_SERVERS
 server name RADIUS01
 server name RADIUS02

aaa authentication login VTY local group RADIUS_SERVERS
aaa authorization exec VTY local group RADIUS_SERVERS

radius server RADIUS01
 address ipv4 x.x.x.x auth-port 1645 acct-port 1646
 key 0 radiuskey

Switch

show interface switchport
show interface brief

Resources

• http://www.eduroam.cz/cs/spravce/ap/ciscoap1230