12-03-2009 03:35 AM
Good day readers,
At our office we have a Cisco router which is also configured as vpn router.
Everything works fine for most costumers, except for one.
He can connect succesfully without problems, but cannot reach anything in our network.
(no ping, no rdp, no file sharing etc.)
We think the problem persists in NAT, so in the Cisco client there is an option “transparant tunneling”, thinking that would solve our problem we tried to enable it.
Not with any succes, with that option enabled we can not even connect (from that one costumer, and ourself as a test).
What do we to do to enable this option?
Below is my config
!
version 12.4
no service pad
service tcp-keepalives-in
service timestamps debug datetime localtime
service timestamps log datetime localtime
service password-encryption
!
hostname C1841
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
no logging monitor
enable secret 5 xxxxxxxxxxxxxxxxxxx
!
aaa new-model
!
!
aaa authentication login userauthen local
aaa authorization network groupauthor local
!
!
aaa session-id common
dot11 syslog
ip source-route
!
!
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.10.1 192.168.10.50
ip dhcp ping packets 3
!
ip dhcp pool Lokaal
import all
network 192.168.10.0 255.255.255.0
default-router 192.168.10.1
dns-server xxx.xxx.235.1 xxx.xxx.235.2
domain-name xxxxxxxxx
lease 0 1
!
!
ip cef
no ip domain lookup
ip multicast-routing
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
username xxxxxxx privilege 15 secret 5 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx password 7 xxxxxxx
username xxxxxxx
username xxxxxxx
username xxxxxxx privilege 15 secret 5 xxxxxxx
archive
log config
hidekeys
!
!
crypto isakmp policy 1
encr aes
authentication pre-share
group 2
!
crypto isakmp client configuration group stream
key xxxxxxx
dns xxxxxxx
domain xxxxxxx
pool ippool
acl 101
!
!
crypto ipsec transform-set myset esp-des esp-md5-hmac
!
crypto dynamic-map dynmap 10
set transform-set myset
reverse-route
!
!
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
!
!
!
!
!
!
interface FastEthernet0/0
description LAN Inside Connection
ip address 192.168.10.1 255.255.255.0
ip pim sparse-dense-mode
ip virtual-reassembly
ip tcp adjust-mss 1452
duplex auto
speed auto
!
interface FastEthernet0/1
description wan Link to CPE
no ip address
ip virtual-reassembly
load-interval 30
speed 100
full-duplex
pppoe enable group global
pppoe-client dial-pool-number 1
!
interface Dialer1
description Traffic PPPoE Connection
mtu 1492
ip unnumbered FastEthernet0/0
ip verify unicast reverse-path
ip pim sparse-dense-mode
ip virtual-reassembly
encapsulation ppp
dialer pool 1
dialer-group 1
snmp trap ip verify drop-rate
no cdp enable
ppp authentication pap callin
ppp pap sent-username xxxxxxx password 7 xxxxxxx
crypto map clientmap
!
ip local pool ippool 192.168.11.10 192.168.11.90
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer1
no ip http server
no ip http secure-server
!
!
!
access-list 1 permit any
access-list 101 permit ip 192.168.11.0 0.0.0.255 192.168.10.0 0.0.0.255
access-list 101 permit ip 192.168.10.0 0.0.0.255 any
access-list 101 permit ip 192.168.11.0 0.0.0.255 any
dialer-list 1 protocol ip permit
no cdp run
!
!
!
!
!
!
control-plane
!
!
!
line con 0
line aux 0
line vty 0 4
transport input telnet
line vty 5 15
transport input telnet
!
scheduler allocate 20000 1000
end
excuses for my lousy english.
Thanks in advance,
Luuk
12-07-2009 10:05 AM
Hi Luuk,
IOS software has the tranparent tunneling always on. Once the VPN Client trying to connect has this option checked, it will be used IF there is any device NATting in the path between the router and the client. This means the packets will have an extra encapsulation (UDP 4500) before being encrypted.
What may be happening is that ISPs in the path may block this well known ports (UDP 500, UDP 4500) and well known protocols.
What I would suggest you is to enable a feature called IPsec over TCP.
1. In the IOS, you can enter "crypto ctcp port 10000"
2. In the VPN Client, select the connection. Click modify, go to 'transport' tb and select IPsec over TCP (default port is already 10000, but if not, change it to it).
This command does not prevent VPN from working on defulat UDP port 500. It just adds another option to connecting clients (that may be blocked on defualt ports by the ISPs).
Hope this helps you.
Cheers,
Pedro
12-08-2009 06:28 AM
pedro, thanks for your reply.
Unfortunately your solution didn't help, or do i have to change some other settings?
But since my access-list only has permit, it should work without any more changes, am i right?
Luuk
12-08-2009 07:50 AM
Hi Luuk,
Actually I was reviewing you ACL 101 and I have some remarks.
Since this is the ACL that will select traffic for VPN, I suggest you to have only one statement:
access-list 101 permit ip 192.168.10.0 0.0.0.255 192.168.11.0 0.0.0.255
The other ones, as they contain "any" is not really recommndable since this can create divergencies in the crypto process.
Try to connect the client the same it was connecting at the very begining, but with this change in the ACL.
Thanks,
Pedro
12-09-2009 05:09 AM
Hi Pedro,
there is a pause on the project since they are getting a new connection.
If i cant get it to work after the changes, i will post it again here.
anyway, thanks for your time and maybe we talk to each other again after the changes.
thanks,
Luuk
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