What is a VPN?
A Virtual Private Network is a type of a connection that connects remote user s to their central office using internet. An IPSEC VPN is virtual tunnel through your public ISP network. VPN are highly encrypted and secure connections.
PPTP vs OpenVPN
how to setup a vpn on Cisco:
This article is about the VPN site to site CLI configuration on GNS3, It’s not so much the commands.
I shall divide these configurations into few parts to make it easy to understand i.e.
1. Define isakmp policy and transform set:
Isakam is the protocol that allow all of keys exchange to happen automatically no need to manually configure the VPN. In this step we shall define authentication type, encryption type, hash. Lifetime and define what session keys are used.
2. Create an ACl
Define interesting traffic using an access control list, this ACL is not for deny or permitting some IP addresses but it just says which addresses are encrypted
3. Set up cryto Map and assign this to interface:
In this step we shall tie up all piece so that we can apply to an interface
Us site config:
US(config)#int s1/0
US(config-if)#ip address 50.0.0.1 255.255.255.0
US(config-if)#no shut
US(config)#int loop 1
US (config-if)#ip address 10.1.1.1 255.255.255.0
US(config)#router rip
US(config-router)#version 2
US(config-router)#network 10.1.1.0
US(config-router)#network 50.0.0.0
US(config-router)#no auto-summary
Step-1 :
US(config)#crypto isakmp policy 7
US(config-isakmp)#authentication pre-share
US(config-isakmp)#encryption aes 128
US(config-isakmp)#group 2
US(config-isakmp)#hash sha
US(config-isakmp)#lifetime 100
US(config-isakmp)#ex
US(config)#crypto isakmp key 0 vpnkey address 192.168.1.1 no-xauth
US(config)#crypto ipsec transform-set vpntrans esp-aes 128 esp-sha-hmac
Step-2
US(config)#ip access-list extended vpn-acl
US(config-ext-nacl)# permit ip 50.0.0.0 0.0.0.255 172.16.0.0 0.0.255.255
Step-3
US(config)#crypto map vpn-map 10 ipsec-isakmp
US(config-crypto-map)#set peer 192.168.1.1
US(config-crypto-map)#match address vpn-acl
US(config-crypto-map)#set transform-set vpntrans
US(config)#int s1/0
US(config-if)#cry
US(config-if)#crypto map vpn-map
ISP configuration:
ISP#conf t
ISP(config)#int s1/0
ISP(config-if)#ip add 50.0.0.2 255.255.255.0
ISP(config-if)#no shut
ISP(config-if)#ex
ISP(config)#int s1/1
ISP(config-if)#ip add 192.168.1.2 255.255.255.0
ISP(config-if)#no shut
ISP(config)#router ri
ISP(config-router)#version 2
ISP(config-router)#network 50.0.0.0
ISP(config-router)#network 192.168.1.0
ISP(config-router)#no auto-summary
Pakistan site config:
Step-1 :
Pakistan#conf t
Pakistan(config)#crypto isakmp policy 7
Pakistan(config-isakmp)# authentication pre-share
Pakistan(config-isakmp)#encryption aes 128
Pakistan(config-isakmp)#encryption aes 128
Pakistan(config-isakmp)# group 2
Pakistan(config-isakmp)# lifetime 100
Pakistan(config-isakmp)#crypto isakmp key 0 vpnkey address 50.0.0.1 no-xauth
Pakistan(cfg-crypto-trans)#ex
Pakistan(config)#crypto ipsec transform-set vpntrans esp-aes esp-sha-hmac
Step-2
Pakistan(config)#ip access-list extended vpn-acl
Pakistan(config-ext-nacl)# permit ip 172.16.0.0 0.0.255.255 50.0.0.0 0.0.0.255
Pakistan(config-ext-nacl)#ex
Step-3
Pakistan(cfg-crypto-trans)#crypto map vpn-map 10 ipsec-isakmp
Pakistan(config-crypto-map)# set peer 50.0.0.1
Pakistan(config-crypto-map)# set transform-set vpntrans
Pakistan(config-crypto-map)# match address vpn-acl
Pakistan(config)#interface Serial1/0
Pakistan(config-if)#crypto map vpn-map
Site to site VPN verfication Commands:
Show crypto isakam sa
nice great job.
ReplyDeleteIt's really a nice job...! I only have a doubt. In this case, what are the loopback interfaces for? Needed for what? Are they necessary? Why? What are their function in this scenario?
ReplyDeleteThank you,
David
loopbacks are just representing yr internal LAN users at these sites...i am using loopbks here just for testing purposes..
ReplyDeleteThis comment has been removed by a blog administrator.
ReplyDeletenice job my friend
ReplyDeleteFrom the paki router is missing the se 1/0 config, the rip config and its advertized networks, and all the loopback networks
Great job, but how did you configure the ISP cloud ?
ReplyDeleteadd router and configure
Delete...With serial interfaces I mean, I only manage to put my computer's interfaces on it.
ReplyDeletehi, thank you for sharing this with us.
ReplyDeleteI just noticed that there are configurations not listed in pakistan router.
hash sha
crypto isakmp key 0 vpnkey address 50.0.0.1 no-xauth
hey nice job!!!
ReplyDeleteI have notice that you missed some other configs in Pakistan router.
encryption aes 128
yes, that is added now. thank you
Deletethank you
ReplyDeleteDear sir,
ReplyDeleteI am very extremely happy to see this site, i think that it look so good.
Thank you
Sincerely
sothea
thank u.. :)
DeleteThis comment has been removed by the author.
ReplyDeleteIm trying to configure nat + vpn tunnel in the same router so what extra configuration do i need to do?
ReplyDeleteDo I need to create a tunnel interface?
yes, you configure both on same router...first configure NAT and then create VPN tunnel...
ReplyDeletethanks for sharing,
ReplyDeletebut i have a question, how can we test the security/encryption ?
i have build the topology and config more or less like yours and the "Show crypto ipsec sa" confirm that the packet has been encrypted/decrypted.
but when i tried to do telnet, the telnet message still can be read with wireshark...
hi bro...please i need ur help in my project a bit...
ReplyDeletejust i am configring my vpn ipsec but it shows
R7#show crypto map
Crypto Map "pakistan" 1 ipsec-isakmp
WARNING: This crypto map is in an incomplete state!
(missing peer or access-list definitions)
Peer = 192.168.0.2
Extended IP access list pakistan
Security association lifetime: 4608000 kilobytes/86400 seconds
PFS (Y/N): Y
DH group: group1
Transform sets={
fawad,
}
Interfaces using crypto map pakistan:
FastEthernet1/1
FastEthernet2/0
The GRE tunnel can't be create as US block all vpn tunnel from Pakistan due to terrorism.
ReplyDeleteHow did you configure 2 routers to connect 1 cloud in GNS3?
ReplyDeleteGreat job!!thank you
ReplyDeletehi thanks. but how can i connect two routers to cloud ?
ReplyDeleteFor people asking about the cloud connection. Ignore the cloud, just place ISP router in between the US and Pakistan and configure it as shown. The cloud is a bit misleading as it is just hiding the ISP router in the diagram.
ReplyDeleteI have done all the same procedure... All is well but the main purpose is not achieved...As you showed at the last ISAKMP sa are shown..But as i did the same procedure but no security associations are found...Let me paste my running config for both....
ReplyDeleteUS#show run
US#show running-config
Building configuration...
Current configuration : 1627 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname US
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
!
!
ip cef
no ip domain lookup
ip domain name lab.local
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
crypto isakmp policy 1
crypto isakmp key VPNKEY address 192.168.1.1 no-xauth
!
!
crypto ipsec transform-set VPNTRANS esp-aes 256
!
crypto map VPN-MAP 10 ipsec-isakmp
set peer 192.168.1.1
set transform-set VPNTRANS
match address VPN-ACL
!
!
!
!
interface Loopback1
ip address 10.1.1.1 255.255.255.0
!
interface Serial0/0
ip address 50.0.0.1 255.255.255.0
serial restart-delay 0
crypto map VPN-MAP
!
interface Serial0/1
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/3
no ip address
shutdown
serial restart-delay 0
!
interface Ethernet1/0
ip address 9.9.9.2 255.255.255.0
half-duplex
!
interface Ethernet1/1
no ip address
shutdown
half-duplex
!
interface Ethernet1/2
no ip address
shutdown
half-duplex
!
interface Ethernet1/3
no ip address
shutdown
half-duplex
!
router rip
version 2
network 9.0.0.0
network 10.0.0.0
network 50.0.0.0
no auto-summary
!
no ip http server
no ip http secure-server
!
!
!
!
ip access-list extended VPN-ACL
permit ip 10.1.1.0 0.0.0.255 172.16.0.0 0.0.255.255
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
line vty 0 4
login
!
!
end
PK#show runn
PK#show running-config
Building configuration...
Current configuration : 1749 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname PK
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
!
!
ip cef
no ip domain lookup
ip domain name lab.local
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
crypto isakmp policy 1
crypto isakmp key VPNKEY address 50.0.0.1 no-xauth
!
!
crypto ipsec transform-set VPNTRANS esp-aes 256
!
Nice work!!!!!!!!!!!!
ReplyDeleteBut I have some doubt....RIP is configured everywhere and the net work is reachable through RIP, then why do we need to configure VPN?
I have a question, if rip was not configured, would the two routers able to reach each other through VPN?
ReplyDeletewiil rips multicast traffic will go this path ???? i am confusing
ReplyDeletei think multycast traffic only pass gre tunnel....then how this possible ...pls help me .
how to accsess router from cmd?because i do "show crypto isakmp sa" gns3 dont show anything.
ReplyDeleteI have used your exemplo to do my lab, is ready..
ReplyDeleteThanks for posting
I though the loopbacks are supposed to be private and not reachable via RIPv2?..!
ReplyDeleteI have no idea on GNS3, but i want to simulate this senerior " i have a web application on a host computer and on a virtual machine, now i want to share data between host computer and virtual machine by using VPN and again by using normal Internet" how can i do that in GNS3?
ReplyDeleteHellow Guys! am new in GNS3, i want to share data between host pc and virtual machine by using VPN and again by using normal internet. How can i do that in GNS3?
ReplyDelete