Cisco Easy VPN Router-to-Router

Cisco Easy VPN is not a new technology. Actually it is pretty old, but still used by many companies or people to connect remote site / remote workers to headquarter.

A few days ago I was looking to connect a remote site in a simple way but still secure and a colleagues suggested me to use Easy VPN. It supposed to be a simple configuration and it was after solving all issues that came into play.

First of all, I needed an Easy VPN Router(client) – to – Router(server). The other method is some client (PC) with software connection to Router / PIX / ASA / VPN Concentrator (Server). Something like this:

The idea is that behind the Client router, I will have a group of people who need to connect to the headquarter, so I don’t want each of them to use personal VPN connections. In search of possible configurations, I’ve found this Cisco configuration example. The only issue in that document is that the Easy VPN tunnel needs manual intervention to connect, which I want to avoid.

For those who need a quick and secure Easy VPN connection here is my sample configuration:

EasyVPN-Server

!! We define a new AAA model for authentication and authorization
!! for remote VPN clients
aaa new-model
!
aaa authentication login userauthen local
aaa authorization network groupauthor local
!
!! Generic username and password
username cisco password 0 cisco123
!
!! We configure a crypto isakmp policy. The number and encryption are your choice
crypto isakmp policy 3
encr 3des
authentication pre-share
group 2
!
!! We add a key and ! Important ! “save-password” command
!! “Save-password” allow client to save the password in an automatic vpn connection
!! scenario
crypto isakmp client configuration group vpngrp
key cisco123
save-password
!
!! The IPSec transform set; You can pick a stronger one like esp-aes 256, but
!! for this example will work fine
crypto ipsec transform-set myset esp-3des esp-sha-hmac
!
!! We get everything together in a crypto dynamic map
crypto dynamic-map dynmap 10
set transform-set myset
!
crypto map clientmap client authentication list userauthen
crypto map clientmap isakmp authorization list groupauthor
crypto map clientmap client configuration address respond
crypto map clientmap 10 ipsec-isakmp dynamic dynmap
!
!! Add the crypto map on the WAN interface or where your VPN tunnels will terminate
interface x/y
description WAN
crypto map clientmap

EasyVPN-Client

!! On the remote side we define an Easy VPN client
!! connect auto – means it will connect automatically
!! network-extension – connection between remote side LAN and server LAN will
!! not need NAT
!! peer is the VPN server IP address
!! xauth mode has to be local for auto connection without manual intervention
crypto ipsec client ezvpn ez
connect auto
group vpngrp key cisco123
mode network-extension
peer 192.168.0.2
username cisco password cisco123
xauth userid mode local
!
!! Apply the already defined crypto to WAN interface
!! This will be automatically the Outside interface, even if you don’t
!! add the “outside” keyword at the end of the command
interface x/y
description WAN
crypto ipsec client ezvpn ez
!
!! Apply it on ALL L3 LAN interfaces that needs to communicate over VPN
!! more, you need to specifiy the keyword “inside”
interface x/y
description ANY L3 LAN interface (SVI / Physical)
crypto ipsec client ezvpn ez inside

To test if your tunnel is up, issue the following command on the EasyVPN client router

#show crypto ipsec client ezvpn
Easy VPN Remote Phase: 8

Tunnel name : TEST
Inside interface list: GigabitEthernet0/0, GigabitEthernet0/1
Outside interface: FastEthernet0/0
Current State: IPSEC_ACTIVE
Last Event: MTU_CHANGED
Save Password: Allowed
Current EzVPN Peer: 192.168.0.2

As you can see the Current State shows IPSEC_ACTIVE

Other commands that will help you see if everything is ok (this can be run on client or server side)
#show crypto isakmp sa
! Look for the “state” (it has to be QM_IDLE) and
! “status” (has to be ACTIVE)

#show crypto ipsec sa
! Look for #pkts encaps and #pkts decaps; the decimal values should be close

I hope this will help you. If anything is unclear please ask in comments.

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