Filtering vpn pptp access

[Stelios]

Hi ,
I want to filter the vpn pptp access to my PIX. The remote client has a static ip.
My network is like this ..
LAN<->192.168.1.21(PIX501)192.168.0.2<->192.168.0.1(router)internet

The router is doing port forward for pptp

I have tried these commands but they don't seem to be working.

access-list vpn_in permit tcp host <remote_static_ip> host 192.168.0.2 eq 1723
access-list vpn_in permit gre <remote_static_ip> host 192.168.0.2
access-group vpn_in in interface outside

Is it OK to use access-list for vpn termination on the pix outside interface?

Any suggestions how to do it?

Thanks

============================
Stelios Agapiou

 

[LloydSev]

So to better understand what you are doing..

You have a client computer, which is attempting to connect via VPN.

Is it attempting to connect via VPN to the PIX, or to a device just beyond the PIX?

Computer/Network Technician
CCNA

 

[Stelios]

Hi LloydSev,

The client computer connects via VPN to the PIX. The PIX is the VPN server.


============================
Stelios Agapiou

 

[LloydSev]

ok.. then another question..

do you have the line "sysopt connection permit-pptp" in your config?

Computer/Network Technician
CCNA

 

[Stelios]

Hi,
yes "sysopt connection permit-pptp" was in the config. And I guess it should not be there.
I have check on that command and it seems to allows pptp traffic to bypass access-list command statement checking.

I remove the comand and tried again. It still allows me to connect to the PIX.



============================
Stelios Agapiou

 

[LloydSev]

the main question is this... why do you have the PIX setup to accept PPTP connections if you want it to port forward them?

Computer/Network Technician
CCNA

 

[Stelios]

Hi again LloydSev,
I have the pix behind the router. The router is doing port forward or Virtual server (1723 192.168.0.2) and is connected to the internet.
The PIX is not doing port forward.

How can the remote client see and connect to the PIX via VPN?
Is the there a better way to do it?

I'm showing below the PIX configuration to make things better.
The reason I'm allowing only the network 195.14.0.0 is because you get IPs in that range when you dial-up. It is easy for me to check the access lists if they are working.
I also added the command
access-list vpn_in permit icmp any any
so I can ping an inside address e.g 192.168.1.1

PIX Version 6.3(1)
interface ethernet0 auto
interface ethernet1 100full
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password 8Ry2YjIyt7RRXU24 encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
hostname pixfirewall
domain-name ciscopix.com
clock timezone EEST 2
clock summer-time EEDT recurring last Sun Mar 3:00 last Sun Oct 4:00
fixup protocol ftp 21
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol http 80
fixup protocol ils 389
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol sip 5060
fixup protocol sip udp 5060
fixup protocol skinny 2000
fixup protocol smtp 25
fixup protocol sqlnet 1521
names
access-list inside_outbound_nat0_acl permit ip any 192.168.1.0 255.255.255.192
access-list vpn_in permit tcp 195.14.0.0 255.255.0.0 any eq pptp
access-list vpn_in permit gre 195.14.0.0 255.255.0.0 any
access-list vpn_in permit icmp any any
pager lines 24
mtu outside 1500
mtu inside 1500
ip address outside 192.168.0.2 255.255.255.0
ip address inside 192.168.1.21 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool pptp-pool 192.168.1.30-192.168.1.39
pdm location 192.168.1.0 255.255.255.192 outside
pdm location 195.14.142.243 255.255.255.255 outside
pdm location 195.14.0.0 255.255.0.0 outside
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list inside_outbound_nat0_acl
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
access-group vpn_in in interface outside
route outside 0.0.0.0 0.0.0.0 192.168.0.1 1
timeout xlate 0:05:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h225 1:00:00
timeout h323 0:05:00 mgcp 0:05:00 sip 0:30:00 sip_media 0:02:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server RADIUS protocol radius
aaa-server LOCAL protocol local
http server enable
http 192.168.1.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
telnet timeout 5
ssh timeout 5
console timeout 0
vpdn group PPTP-VPDN-GROUP accept dialin pptp
vpdn group PPTP-VPDN-GROUP ppp authentication mschap
vpdn group PPTP-VPDN-GROUP ppp encryption mppe auto
vpdn group PPTP-VPDN-GROUP client configuration address local pptp-pool
vpdn group PPTP-VPDN-GROUP client configuration wins 192.168.1.1
vpdn group PPTP-VPDN-GROUP pptp echo 60
vpdn group PPTP-VPDN-GROUP client authentication local
vpdn username vpnuser password *********
vpdn enable outside
dhcpd lease 3600
dhcpd ping_timeout 750
terminal width 80
Cryptochecksum:8c4fe037d94749bd98bc17a6ca89864f
: end
[OK]

============================
Stelios Agapiou

 

[LloydSev]

OK.. I'm still struggling to understand what the problem is, so bear with me..

Your router is port forwarding PPTP and GRE to the PIX.. so you DO want the PIX to accept the PPTP? In an earlier post, it seemed as if you didn't want the PIX to be accepting the PPTP, which is why I had asked why you had it set up.

The remote client sees the PIX, because the Router is port forwarding to it..

Also.. the access-list for stopping port 1723 traffic should be placed on the router, not on the PIX.. as the traffic never intends to go through the PIX.. and therefore can not have an internal address when placed on the PIX.

Computer/Network Technician
CCNA

 

[Stelios]

I see my mistake ..
On my first post I wrote that I wanted to filter the VPN PPTP access to my PIX.
I should say that I want to allow only a specific address to go through (the router and terminate on the PIX) as VPN PPTP and block the rest of the addresses. If somebody else tries to connect VPN PPTP it should not allow it.

But OK , I see you point...its better to place the acces-list on the router. I will try that.

Thanks for all the help LloydSev


============================
Stelios Agapiou

 

[LloydSev]

No problem.

Computer/Network Technician
CCNA