PIX501 VPN Revisited

[QCumber]

Hi again,

after a few weeks sorting other things out, I've returned to the pain-in-the-a** VPN config on my PIX-501. My hopes that the thing would have self healed over the last few weeks have been dashed (unsurprisingly).

To recap, I have very little Cisco knowledge, but have somehow managed to get the 501 up and running with one exception - VPN. Following suggestions from the guys here I reconfigured the VPN settings to use the Cisco VPN client and I can now connect OK (VPN allocated IP address, etc). But despite ticking the "LAN access" box I have no access to any network resources, can't even ping IP's.

I'm wondering if I have to set up a separate set of access rules for the VPN DHCP range?

Here is the current config. As always, any help would be greatly appreciated (config changes / samples even more so!).

Si.

PS The DNS servers are right, they're ISP allocated.



PIX Version 6.2(2)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password XXX encrypted
passwd XXX encrypted
hostname cerberus
domain-name testsys.co.uk
fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol ils 389
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol sip 5060
fixup protocol skinny 2000
names
name 212.XXX.XXX.XXX mail.vi.net
name 212.XXX.XXX.XXX mail2.vi.net
name 192.168.1.3 Floyd
name 192.168.1.5 Emerson
name 192.168.1.1 Jethro
name 192.168.1.0 Remote_VPN
name 192.168.111.0 VPN
object-group network vi.mail
description VI Mail Server Group
network-object XXX.XXX.XXX.XXX 255.255.255.255
network-object XXX.XXX.XXX.XXX 255.255.255.255
access-list outside_access_in permit icmp any any echo-reply
access-list outside_access_in permit icmp any any traceroute
access-list outside_access_in permit tcp any host 81.XXX.XXX.XXX eq www
access-list outside_access_in permit tcp any host 81.XXX.XXX.XXX eq ftp
access-list outside_access_in permit tcp any host 81.XXX.XXX.XXX eq ftp-data
access-list inside_outbound_nat0_acl permit ip any 192.168.1.192 255.255.255.224
access-list inside_outbound_nat0_acl permit ip any VPN 255.255.255.0
access-list inside_outbound_nat0_acl permit ip Remote_VPN 255.255.255.0 VPN 255.255.255.0
access-list outside_cryptomap_dyn_20 permit ip any VPN 255.255.255.0
access-list testsys_splitTunnelAcl permit ip host Remote_VPN any
access-list testsys_splitTunnelAcl permit ip Remote_VPN 255.255.255.0 any
access-list inside_access_in permit tcp any any
access-list inside_access_in permit ip any any
access-list inside_access_in permit udp any any
access-list inside_access_in permit icmp any any
access-list testsys_splitTunnelAcl_1 permit ip any any
access-list outside_cryptomap_dyn_40 permit ip any VPN 255.255.255.0
pager lines 24
logging on
logging buffered warnings
logging trap informational
logging host inside 192.168.1.29
interface ethernet0 10baset
interface ethernet1 10full
mtu outside 1500
mtu inside 1500
ip address outside 81.XXX.XXX.XXX 255.255.255.192
ip address inside 192.168.1.19 255.255.255.0
ip verify reverse-path interface outside
ip verify reverse-path interface inside
ip audit info action alarm
ip audit attack action alarm
ip local pool Remote 192.168.111.1-192.168.111.254
pdm location 192.168.1.20 255.255.255.255 inside
pdm location 192.168.1.29 255.255.255.255 inside
pdm location 192.168.0.0 255.255.255.0 outside
pdm location Jethro 255.255.255.255 inside
pdm location 192.168.1.192 255.255.255.224 outside
pdm location VPN 255.255.255.255 outside
pdm location Emerson 255.255.255.255 inside
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 81.XXX.XXX.XXX-81.XXX.XXX.XXX netmask 255.255.255.192
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
static (inside,outside) 81.XXX.XXX.XXX Emerson netmask 255.255.255.255 0 0
access-group outside_access_in in interface outside
access-group inside_access_in in interface inside
route outside 0.0.0.0 0.0.0.0 81.XXX.XXX.XXX 1
timeout xlate 0:05:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 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 Remote_VPN 255.255.255.0 inside
http 192.168.1.29 255.255.255.255 inside
http 192.168.1.20 255.255.255.255 inside
no snmp-server location
no snmp-server contact
snmp-server community public
snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
sysopt connection permit-pptp
sysopt connection permit-l2tp
no sysopt route dnat
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto dynamic-map outside_dyn_map_1 20 match address outside_cryptomap_dyn_20
crypto dynamic-map outside_dyn_map_1 20 set transform-set ESP-3DES-MD5
crypto dynamic-map outside_dyn_map_1 40 match address outside_cryptomap_dyn_40
crypto dynamic-map outside_dyn_map_1 40 set transform-set ESP-3DES-SHA
crypto map outside_map_1 65535 ipsec-isakmp dynamic outside_dyn_map_1
crypto map outside_map_1 interface outside
isakmp enable outside
isakmp policy 20 authentication rsa-sig
isakmp policy 20 encryption des
isakmp policy 20 hash sha
isakmp policy 20 group 1
isakmp policy 20 lifetime 86400
isakmp policy 40 authentication pre-share
isakmp policy 40 encryption 3des
isakmp policy 40 hash md5
isakmp policy 40 group 2
isakmp policy 40 lifetime 86400
isakmp policy 60 authentication pre-share
isakmp policy 60 encryption 3des
isakmp policy 60 hash sha
isakmp policy 60 group 2
isakmp policy 60 lifetime 86400
vpngroup testsys address-pool Remote
vpngroup testsys dns-server 194.168.4.100 194.168.8.100
vpngroup testsys wins-server Jethro
vpngroup testsys default-domain testsys.co.uk
vpngroup testsys split-tunnel testsys_splitTunnelAcl_1
vpngroup testsys idle-time 1800
vpngroup testsys password ********
telnet 192.168.1.20 255.255.255.255 inside
telnet 192.168.1.29 255.255.255.255 inside
telnet timeout 20
ssh timeout 5
dhcpd auto_config outside
terminal width 80

 

[routerman]

When the client is connected what tunnels are established. If you issue the SHOW CRYPTO ISAKMP SA first it should indicate that the ISAKMP is in QM_IDLE.

Then SHOW CRYPTO IPSEC SA, look at the tunnel source and destination networks, are these what you would expect?

The output shows the local and remote ident, which is the source and destination tunnel end points.

 

[routerman]

Have been comparing this with a similar set up I did some time ago. Try removing the commands:

crypto dynamic-map outside_dyn_map_1 20 match address outside_cryptomap_dyn_20
crypto dynamic-map outside_dyn_map_1 40 match address outside_cryptomap_dyn_40

I dont see the need for these as the connection will always be made from the client to the PIX, and the tunnel endpoints negotiated in the initial set up phase.

I based my solution on the following URL

http://www.cisco.com/warp/customer/110/pix3000.html

 

[QCumber]

Hi Routerman,

thanks for the suggestions, I'll give them a try over the weekend.

Simon.

 

[routerman]

Another thought, when you make the changes dont forget to issue the CLEAR CRYPTO SA and CLEAR CRYPTO IPSEC SA to drop the existing security associations.

 

[yizhar]

HI.

> access-list testsys_splitTunnelAcl permit ip host Remote_VPN any
> access-list testsys_splitTunnelAcl permit ip Remote_VPN 255.255.255.0 any
I think that the above lines are wrong.

Try without split tunnel, and/or try with the following:

no access-list testsys_splitTunnelAcl
access-list testsys_splitTunnelAcl permit ip access-list 192.168.1.0 255.255.255.0 192.168.111.0 255.255.255.0

Bye


Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar

 

[QCumber]

Thanks for the help guys, but the damn thing still won't let me access any LAN resources. Do I have to put explicit rules in to allow all the windows specific NetBios stuff through the wall (with the VPN allocated IP addresses 192.168.111.x as the source?)

All the complicated IPSEC stuff appears to be working fine, VPN client shows the secured routes, the client gets the IP address, DNS and WINS info from the VPN connection, but the "Local LAN" option always shows as disabled on the client.

Here are the results of the traces Routerman suggested I run, they look OK to me. I'll post the config again cos I've made the changes you guys suggested.

I'm begining to wish I'd stuck with a dial up RAS solution!

=====================================================


Result of PIX command: "show crypto isakmp sa"

Total : 1
Embryonic : 0
dst src state pending created
81.xxx.xxx.xxx 158.152.yyy.yyy QM_IDLE 0 2




Result of PIX command: "show crypto ipsec sa"

interface: outside
Crypto map tag: outside_map_1, local addr. 81.xxx.xxx.xxx
local ident (addr/mask/prot/port): (0.0.0.0/0.0.0.0/0/0)
remote ident (addr/mask/prot/port): (192.168.111.1/255.255.255.255/0/0)
current_peer: 158.152.yyy.yyy
dynamic allocated peer ip: 192.168.111.1
PERMIT, flags={}
#pkts encaps: 0, #pkts encrypt: 0, #pkts digest 0
#pkts decaps: 22, #pkts decrypt: 22, #pkts verify 22
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0, #pkts decompress failed: 0
#send errors 0, #recv errors 0
local crypto endpt.: 81.xxx.xxx.xxx, remote crypto endpt.: 158.152.yyy.yyy
path mtu 1500, ipsec overhead 56, media mtu 1500
current outbound spi: 9ee652e6
inbound esp sas:
spi: 0xca8469a6(3397675430)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 1, crypto map: outside_map_1
sa timing: remaining key lifetime (k/sec): (4607997/28741)
IV size: 8 bytes
replay detection support: Y
inbound ah sas:
inbound pcp sas:
outbound esp sas:
spi: 0x9ee652e6(2665894630)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 2, crypto map: outside_map_1
sa timing: remaining key lifetime (k/sec): (4608000/28741)
IV size: 8 bytes
replay detection support: Y
outbound ah sas:
outbound pcp sas:



===================================================

PIX Version 6.2(2)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password 2KFQnbNIdI.2KYOU encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
hostname cerberus
domain-name testsys.co.uk
fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol ils 389
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol sip 5060
fixup protocol skinny 2000
names
name 212.xxx.xxx.xxx mail.vi.net
name 212.xxx.xxx.xxx mail2.vi.net
name 192.168.1.3 Floyd
name 192.168.1.5 Emerson
name 192.168.1.1 Jethro
name 192.168.1.0 Remote_VPN
name 192.168.111.0 VPN
object-group network vi.mail
description VI Mail Server Group
network-object xxx.xxx.xxx.xxx 255.255.255.255
network-object xxx.xxx.xxx.xxx 255.255.255.255
access-list outside_access_in permit ip VPN 255.255.255.0 Remote_VPN 255.255.255.0
access-list outside_access_in permit icmp any any echo-reply
access-list outside_access_in permit icmp any any traceroute
access-list outside_access_in permit tcp any host 81.xxx.xxx.xxx eq www
access-list outside_access_in deny tcp any host 81.xxx.xxx.xxx eq www
access-list outside_access_in permit tcp any host 81.xxx.xxx.xxx eq ftp
access-list outside_access_in permit tcp any host 81.xxx.xxx.xxx eq ftp-data
access-list inside_outbound_nat0_acl permit ip any 192.168.1.192 255.255.255.224
access-list inside_outbound_nat0_acl permit ip any VPN 255.255.255.0
access-list inside_outbound_nat0_acl permit ip Remote_VPN 255.255.255.0 VPN 255.255.255.0
access-list inside_access_in permit tcp any any
access-list inside_access_in permit ip any any
access-list inside_access_in permit udp any any
access-list inside_access_in permit icmp any any
access-list testsys_splitTunnelAcl_1 permit ip host Remote_VPN any
access-list testsys_splitTunnelAcl_1 permit ip Remote_VPN 255.255.255.0 VPN 255.255.255.0
pager lines 24
logging on
logging buffered warnings
logging trap informational
logging host inside 192.168.1.29
interface ethernet0 10baset
interface ethernet1 10full
mtu outside 1500
mtu inside 1500
ip address outside 81.xxx.xxx.xxx 255.255.255.192
ip address inside 192.168.1.19 255.255.255.0
ip verify reverse-path interface outside
ip verify reverse-path interface inside
ip audit info action alarm
ip audit attack action alarm
ip local pool Remote 192.168.111.1-192.168.111.254
pdm location 192.168.1.20 255.255.255.255 inside
pdm location 192.168.1.29 255.255.255.255 inside
pdm location 192.168.0.0 255.255.255.0 outside
pdm location Jethro 255.255.255.255 inside
pdm location 192.168.1.192 255.255.255.224 outside
pdm location VPN 255.255.255.255 outside
pdm location Emerson 255.255.255.255 inside
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 81.xxx.xxx.xxx-81.xxx.xxx.xxx netmask 255.255.255.192
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
static (inside,outside) 81.xxx.xxx.xxx Emerson netmask 255.255.255.255 0 0
access-group outside_access_in in interface outside
access-group inside_access_in in interface inside
route outside 0.0.0.0 0.0.0.0 81.xxx.xxx.xxx 1
timeout xlate 0:05:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 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 Remote_VPN 255.255.255.0 inside
http 192.168.1.29 255.255.255.255 inside
http 192.168.1.20 255.255.255.255 inside
no snmp-server location
no snmp-server contact
snmp-server community public
snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
sysopt connection permit-pptp
sysopt connection permit-l2tp
no sysopt route dnat
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto dynamic-map outside_dyn_map_1 20 set transform-set ESP-3DES-MD5
crypto dynamic-map outside_dyn_map_1 40 set transform-set ESP-3DES-SHA
crypto map outside_map_1 65535 ipsec-isakmp dynamic outside_dyn_map_1
crypto map outside_map_1 interface outside
isakmp enable outside
isakmp policy 20 authentication rsa-sig
isakmp policy 20 encryption des
isakmp policy 20 hash sha
isakmp policy 20 group 1
isakmp policy 20 lifetime 86400
isakmp policy 40 authentication pre-share
isakmp policy 40 encryption 3des
isakmp policy 40 hash md5
isakmp policy 40 group 2
isakmp policy 40 lifetime 86400
isakmp policy 60 authentication pre-share
isakmp policy 60 encryption 3des
isakmp policy 60 hash sha
isakmp policy 60 group 2
isakmp policy 60 lifetime 86400
vpngroup testsys address-pool Remote
vpngroup testsys dns-server 194.168.4.100 194.168.8.100
vpngroup testsys wins-server Jethro
vpngroup testsys default-domain testsys.co.uk
vpngroup testsys split-tunnel testsys_splitTunnelAcl_1
vpngroup testsys pfs
vpngroup testsys idle-time 1800
vpngroup testsys password ********
telnet 192.168.1.20 255.255.255.255 inside
telnet 192.168.1.29 255.255.255.255 inside
telnet timeout 20
ssh timeout 5
dhcpd auto_config outside
terminal width 80

 

[routerman]

As you point out, the VPN tunnel is up, so you must be nearly there.
Looking at the show crypto ipsec sa I see decrypted packets, these are received from your VPN client, so traffic from the client is getting to the PIX. However there is no encrypted packets going back to the client.

So I think this is either a filtering problem or a routing issue, as the packets are getting to the PIX they should be getting to the inside network.

Your inside access list should allow any traffic into the PIX, I dont think that its causing the problem. The only downside to removing it, ping replies would'nt get through the PIX, so for testing leave it as it is.

The inside host's you are trying to connect to, do they have either a route back to the client IP address range, or a default route? Both should go via the PIX.

As for the local LAN access, this is for the client to use his locally attached network, not the one at the other end of the VPN. The option on the client is enabled via the split tunnel option, this is configured on the PIX and pushed to the client during the initial connection establishment.

So, regardless of the state of the local lan access checkbox you should be able to connect to the central site.

Finally, one option you have enabled, the ip verify reverse-path may be causing this problem. I've not used this myself, but I know it relies on routing entries in the PIX. I dont think you'll have a route to the client subnet (check with show route) and I wonder if this feature is dropping the client packets?

 

[QCumber]

Thanks routerman!!!

It was the route tables on the inside hosts, there was no entry for the VPN issued DHCP addresses (192.168.111.0). I've added a route and I can now ping the hosts by IP. Name pinging still doesn't work and I can't map drives yet, but I guess I just have to add access list entries for all the microsoft netbios stuff, with 192.168.111.0 as the source?

Thanks again - to everyone that makes this site such a damn useful resource.

 

[routerman]

Well done, we got there at last!!

I had a similar issue using the NetBIios names, It was down to WINS, but I'm struggling to remember the details. In my case (Win98 client) I had to login to the PC first, then connect over the dialup link into the PIX. The PC had to be in the same domain.
Then Network Neighbourhood showed all the hosts in the domain. I had problems browsing other domains, which is why I traced it to a WINS problem.

One thing I can say is that its not the filtering, your already allowing all IP traffic through.

 

[QCumber]

A final note of thanks to all those who offered suggestions. It's all working fine now, and I can look forward to many happy hours "working from home"

Si.