Cisco IOS clock settings

set correct time zone:

clock timezone PCTime -8

 

set summer time old ios:

clock summer-time PCTime date Mar 13 2011 2:00 Nov 6 2011 2:00

 

New IOS have other nice settings, it's need setup just one time:

clock summer-time CDT recurring

 

set ntp server:

ntp server XXX.XXX.XXX.XXX

 

set clock:

clock set 10:30:00 Jul 12 2011

 

show clock:

show clock

VPN syslog error

If vpn is up but you have errors log

%CRYPTO-4-PKT_REPLAY_ERR: decrypt: replay check failed

 

for fix it add to router

crypto ipsec security-association replay window-size 1024

Change your Windows MTU

Example how to find your correct MTU

 

1. Find your Windows MTU:

netsh interface ipv4 show subinterfaces 

 

2. Find your ISP MTU:

ping yourISPgatewayIP -f -l 1400

incrice size until you get:

Packet needs to be fragmented but DF set.

Last sucsess ping size+28 is you correct MTU

 

3. For set MTU:

netsh interface ipv4 set subinterface "Local Area Connection" mtu=1472 store=persistent

 

 

 

  

Flexible NetFlow for IOS

 

If you use vpn links standart netflow don't work with vpn links. You need use flexible netflow.

It works well with vpn links. Update your IOS if your router don't support it.   

 

Example:

 

flow exporter NETFLOW1-EXPORTER

 

 description NetFlow Analyzer

 destination 172.16.0.1

 source Loopback0

 output-features

 transport udp 9996

 export-protocol netflow-v9

!

!

flow exporter NETFLOW2-EXPORTER

 description Scrutinizer

 destination 172.16.0.2

 source Loopback0

 output-features

 transport udp 9996

 export-protocol netflow-v9

!

!

flow monitor NETFLOW1

 record netflow-original

 exporter NETFLOW2-EXPORTER

 exporter NETFLOW1-EXPORTER

 cache timeout active 1

!

!

interface Tunnel12

 ip flow monitor NETFLOW1 input

 ip flow monitor NETFLOW1 output

!

!

interface FastEthernet1

 ip flow monitor NETFLOW1 input

 ip flow monitor NETFLOW1 output

 

 

link: http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6555/ps6601/ps6965/prod_white_paper0900aecd804be1cc.html

 

ssh and MyEnTunnel

I use putty for configure my routers and some time for ssh tunnels for access to home network.

However putty need reconnect every time. MyEnTunnel can reconnect automatically and make your life easy. You can setup a lot of ports. 

For example for 3 RD for home network:

3310:192.168.1.10:3389

3311:192.168.1.11:3389

3312:192.168.1.12:3389

MyEnTunnel is free and you can download it from http://nemesis2.qx.net/pages/MyEnTunnel

Cisco router as dhcp client

Sometimes ISP provide only dhcp ip for branch offices.  When you use firewall, I hope you use it , you need use rule for open dhcp traffic  in your firewall.

interface FastEthernet0/0 ip address dhcp ip access-group ISP in ip access-list extended ISP permit udp any eq bootps any eq bootpc

Bat file for reboot PC remotely

Sometimes you need reboot pc at night. It help you.

@echo off dsquery computer ou=workstations,dc=contoso,dc=com -o rdn > pc_workstations.txt for /F "tokens=*" %%i in (pc_workstations.txt) do call :reboot %%i% goto Ready :Reboot set remotepc=%1% set remotepc=%remotepc:~1,-1% shutdown /f /r /c "Reboot by administrator" /m \\%remotepc% goto :EOF :Ready