Setup VPN on 501 from behind ADSL Router (NATed)

[overdraft015]

I am trying to setup a VPN (vpn client at the moment) on a PIX 501 from behind an ADSL modem. but i cant seem to get this to connect when i go through the modem.

I can get connected using my test config when i connect to the same network as the outside interface. (i.e. the LAN side of the ADSL modem)

Hope that makes sense.

I have tried port forwarding on the modem, putting the pix in the dmz, enabling VPN pass-though etc.. but no success.

Is what i am trying to do even possible?

I havent mentioned any particular brand modem because i need to be able to set this up with any ADSL/DSL modem (within reason of course) as it will need to be integrated with the customers current internet and no new hardware needs to be bought. so if the customer has only 1 public IP then the modem/router needs this and any VPN traffic to port forward to the PIX. (pix conf can be posted but this works if im on the same network as the outside int so dont think this is the problem)


Thank you for your help,

Michael.

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[Supergrrover]

Is the modem doing NAT?

make sure you are using nat-traversal -

crypto isakmp nat-traversal 20

Can you post a scrubbed config?


Brent
Systems Engineer / Consultant
CCNP, CCSP

 

[overdraft015]

yes the modem is doing NAT. i think it was my conf that was the problem. i had no route back out of the router. when i have put the route to the gateway on the outside of the pix it seems to work now. However i dont have the line "crypto isakmp nat-traversal 20" should i add this anyway? would i need to change/remove a current config for that to be used?

Thank you.

heres my conf:

PIX Version 6.3(5)
interface ethernet0 auto
interface ethernet1 100full
nameif ethernet0 outside security0
nameif ethernet1 inside security100
hostname pix
domain-name 1
fixup protocol dns maximum-length 512
fixup protocol ftp 21
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol http 80
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
fixup protocol tftp 69
names
access-list inside_outbound_nat0_acl permit ip any 192.168.24.0 255.255.255.224
access-list outside_cryptomap_dyn_20 permit ip any 192.168.24.0 255.255.255.224
pager lines 24
mtu outside 1500
mtu inside 1500
ip address outside dhcp retry 4
ip address inside 192.168.10.1 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool VPNPL 192.168.24.1-192.168.24.25
pdm location 192.168.10.20 255.255.255.255 inside
pdm location 192.168.1.101 255.255.255.255 outside
pdm location 192.168.1.0 255.255.255.0 outside
pdm location 192.168.24.0 255.255.255.224 outside
pdm location 192.168.24.0 255.255.255.0 outside
pdm history enable
arp timeout 14400
global (outside) 10 interface
nat (inside) 0 access-list inside_outbound_nat0_acl
nat (inside) 10 0.0.0.0 0.0.0.0 0 0
route outside 0.0.0.0 0.0.0.0 192.168.1.1 1
timeout xlate 3:00:00
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 sip-disconnect 0:02:00 sip-invite 0:03:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server TACACS+ max-failed-attempts 3
aaa-server TACACS+ deadtime 10
aaa-server RADIUS protocol radius
aaa-server RADIUS max-failed-attempts 3
aaa-server RADIUS deadtime 10
aaa-server LOCAL protocol local
aaa authentication ssh console LOCAL
http server enable
http 192.168.1.0 255.255.255.0 outside
http 192.168.24.0 255.255.255.0 outside
http 192.168.10.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto dynamic-map outside_dyn_map 20 match address outside_cryptomap_dyn_20
crypto dynamic-map outside_dyn_map 20 set transform-set ESP-3DES-MD5
crypto map outside_map 65535 ipsec-isakmp dynamic outside_dyn_map
crypto map outside_map interface outside
isakmp enable outside
isakmp policy 20 authentication pre-share
isakmp policy 20 encryption 3des
isakmp policy 20 hash md5
isakmp policy 20 group 2
isakmp policy 20 lifetime 86400
vpngroup AITUKVPN address-pool VPNPL
vpngroup AITUKVPN idle-time 1800
vpngroup AITUKVPN password ********
telnet timeout 5
ssh 192.168.1.0 255.255.255.0 outside
ssh 192.168.24.0 255.255.255.0 outside
ssh timeout 5
management-access outside
console timeout 0
dhcpd address 192.168.10.20-192.168.10.30 inside
dhcpd dns 192.168.100.1
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd enable inside
terminal width 80

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[overdraft015]

sorry i meant "no route back out of the pix to the router"

It's not what you know. It's who's on Tek-Tip's

 

[AgentK]

Hi all,

My adsl modem don't do NAT, vpn_client connects okay but there is no traffic between the vpn_client network and corporate network, I may have missed something here.Any pointer, appreicated.

bkfw# wr ter
: Saved
:
PIX Version 6.3(5)
interface ethernet0 10full
interface ethernet1 100full
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password lIdfasjosmca2hP encrypted
passwd 0u6ufbVjUF8BwcgD encrypted
hostname HN_firewall
domain-name Harry_Nutsack LLC.com
fixup protocol dns maximum-length 512
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 pptp 1723
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
no fixup protocol sqlnet 1521
no fixup protocol tftp 69
names
access-list inbound permit icmp any any
access-list inbound permit tcp any any eq ssh
access-list inbound permit tcp any any eq pptp
access-list inbound permit udp any any eq 4569
access-list inbound permit tcp any any eq 2000
access-list vpn_clients permit ip 10.20.0.0 255.255.255.0 10.20.1.0 255.255.255.0
access-list vpn_clients permit ip 192.168.2.0 255.255.255.0 10.20.1.0 255.255.255.0
access-list NONAT permit ip 192.168.2.0 255.255.255.0 10.20.1.0 255.255.255.0
pager lines 24
logging on
logging timestamp
logging console debugging
logging buffered debugging
mtu outside 1500
mtu inside 1500
ip address outside pppoe setroute
ip address inside 192.168.2.99 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool vpn_clientPool 10.20.1.100-10.20.1.150
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list NONAT
nat (inside) 1 192.168.2.0 255.255.255.0 0 0
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
static (inside,outside) tcp interface ssh 192.168.2.244 ssh netmask 255.255.255.255 0 0
static (inside,outside) tcp interface 2000 192.168.2.90 2000 netmask 255.255.255.255 0 0
access-group inbound in interface outside
route inside 10.20.1.0 255.255.255.0 192.168.2.90 1
timeout xlate 3:00:00
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 sip-disconnect 0:02:00 sip-invite 0:03:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server TACACS+ max-failed-attempts 3
aaa-server TACACS+ deadtime 10
aaa-server RADIUS protocol radius
aaa-server RADIUS max-failed-attempts 3
aaa-server RADIUS deadtime 10
aaa-server LOCAL protocol local
snmp-server location
no snmp-server contact
snmp-server community public
snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
crypto ipsec transform-set EL_SET esp-3des esp-md5-hmac
crypto dynamic-map ELNOMAP 10 set transform-set EL_SET
crypto map ELPEER 20 ipsec-isakmp dynamic ELNOMAP
crypto map ELPEER client authentication LOCAL
crypto map ELPEER interface outside
isakmp enable outside
isakmp identity address
isakmp policy 10 authentication pre-share
isakmp policy 10 encryption 3des
isakmp policy 10 hash md5
isakmp policy 10 group 2
isakmp policy 10 lifetime 86400
vpngroup elgroupo address-pool vpn_clientPool
vpngroup elgroupo dns-server 151.164.1.8
vpngroup elgroupo default-domain Harry_Nutsack.com
vpngroup elgroupo idle-time 1800
vpngroup elgroupo password **************
telnet 192.168.2.0 255.255.255.0 inside
telnet timeout 15
ssh 192.168.2.0 255.255.255.0 inside
ssh timeout 15
console timeout 0
vpdn group pppoe_dialout request dialout pppoe
vpdn group pppoe_dialout localname HarryNutsack
vpdn group pppoe_dialout ppp authentication pap
vpdn username Harry_nutsack@myisp.com password mypa$$w0rd
dhcpd address 192.168.2.245-192.168.2.254 inside
dhcpd dns 68.94.157.1
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
dhcpd enable inside
username HNutsack password mypa$$word encrypted privilege 2

firewall#

 

[Supergrrover]

overdraft015,

You definitely need to the default outside route, but you should add this line just in case there is a nat device between your client and the pix.

crypto isakmp nat-traversal 20

Brent
Systems Engineer / Consultant
CCNP, CCSP

 

[overdraft015]

Thanks Brent i will add this.

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