Quick query regarding Cisco documentation

[paulgami]

I'm trying to configure a simple VPN between two PIX 501s - one with a static IP and one on a cable modem.

The guide entitled "Configuring PIX to PIX Dynamic-to-Static IPSec with NAT and Cisco VPN Client" at

http://www.cisco.com/en/US/products...s_configuration_example09186a0080094680.shtml

seems like a perfect guide to follow for those of us not too au-fait with Cisco gear.

Pix1
internal - 10.2.2.1
external - 203.1.1.1

Pix2
internal - 10.1.1.1
external - dhcp

So, I'm reading through the configs and all looks fine until i get to these commands on the Pix with the dynamic IP:

global (outside) 1 204.1.1.10-204.1.1.15
route outside 0.0.0.0 0.0.0.0 204.1.1.2 1

Can someone explain those to me. Why are explicit ip addresses being mentioned on the external interface of this Pix? Aren't they supposed to be dynamic?

The other (static) Pix config has the lines:

<--- global (outside) 1 203.1.1.10-203.1.1.15
route outside 0.0.0.0 0.0.0.0 203.1.1.2 1

Is the 204.x.x.x a typo?
What if I don't have multiple external ip addresses - what do i put in the "global (outside) x.x.x.x...." bit on the dynamic Pix?

 

[dopehead]

What you need instead is, on the cable pix with dynamic ip use "global (outside) 1 interface" which will just use whatever address is assigned to the outside (via dhcp/pppoe).

Also remember that if the cablemodem runs dhcp then you need the "setroute" command after your "ip address outside dhcp" command which will install a default route that you get from the dhcp server @ your isp upon connect.

Jan


Network Systems Engineer
CCNA/CQS/CCSP/Infosec

 

[paulgami]

I've just been informed that the remote PIX can initiate the VPN tunnel but can't do anything else like map drives or ping hosts on the other side.

The VPN light comes on and I can look back in the local PIX's log to see an active IPSec/IKE tunnel at the same time.

I know it's something remarkably simple but I can't see it. Can anyone help?

Configs are below:

REMOTE PIX
PIX Version 6.3(4)
interface ethernet0 100full
interface ethernet1 100full
nameif ethernet0 ou
nameif ethernet1 inside security100
enable password *** encrypted
passwd *** encrypted
hostname remotepix1
domain-name ***
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 101 permit ip 192.168.100.0 255.255.255.0 10.10.10.0 255.255.255.0
pager lines 24
logging on
logging buffered debugging
mtu outside 1500
mtu inside 1500
ip address outside dhcp setroute
ip address inside 192.168.100.1 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list 101
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
conduit permit icmp any any
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 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
http server enable
http 192.168.100.0 255.255.255.0 inside
no snmp-server location
no snmp-server cont
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
crypto ipsec transform-set myset esp-des esp-md5-hmac
crypto map newmap 10 ipsec-isakmp
crypto map newmap 10 match address 101
crypto map newmap 10 set peer (LOCAL PIX external IP)
crypto map newmap 10 set transform-set myset
crypto map newmap interface outside
isakmp enable outside
isakmp key ******** address (LOCAL PIX external IP) netmask 255.255.255.255
isakmp policy 10 authentication pre-share
isakmp policy 10 encryption des
isakmp policy 10 hash md5
isakmp policy 10 group 1
isakmp policy 10 lifetime 1000
telnet timeout 5
ssh timeout 5
console timeout 0
dhcpd address 192.168.100.10-192.168.100.40 inside
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
dhcpd enable inside
terminal width 80




LOCAL PIX
PIX Version 6.3(4)
interface ethernet0 100full
interface ethernet1 100full
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password *** encrypted
passwd *** encrypted
hostname gamipix1
domain-name ***
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 100 permit ip 10.10.10.0 255.255.255.0 192.168.100.0 255.255.255.0
access-list 100 permit ip 10.10.10.0 255.255.255.0 192.168.11.0 255.255.255.0
pager lines 24
logging buffered debugging
mtu outside 1500
mtu inside 1500
ip address outside (LOCAL PIX External IP) 255.255.255.0
ip address inside (LOCAL PIX Internal IP) 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool clientpool 192.168.11.1-192.168.11.50
pdm location 192.168.11.0 255.255.255.0 outside
pdm location 192.168.100.0 255.255.255.0 outside
pdm location 10.10.10.0 255.255.255.255 inside
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list 100
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
conduit permit icmp any any
route outside 0.0.0.0 0.0.0.0 (LOCAL PIX External T1 Gateway IP) 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 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 10.10.10.0 255.255.255.0 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 myset esp-des esp-md5-hmac
crypto dynamic-map cisco 1 set transform-set myset
crypto map dyn-map 20 ipsec-isakmp dynamic cisco
crypto map dyn-map interface outside
isakmp enable outside
isakmp key ******** address 0.0.0.0 netmask 0.0.0.0
isakmp policy 10 authentication pre-share
isakmp policy 10 encryption des
isakmp policy 10 hash md5
isakmp policy 10 group 1
isakmp policy 10 lifetime 1000
isakmp policy 20 authentication pre-share
isakmp policy 20 encryption des
isakmp policy 20 hash sha
isakmp policy 20 group 2
isakmp policy 20 lifetime 86400
vpngroup unityclient address-pool clientpool
vpngroup unityclient dns-server 10.10.10.163
vpngroup unityclient wins-server 10.10.10.163
vpngroup unityclient default-domain ***
vpngroup unityclient idle-time 1800
vpngroup unityclient password ********
telnet timeout 5
ssh 10.10.10.0 255.255.255.0 inside
ssh timeout 5
console timeout 0
username *** password *** encrypted privilege 15
terminal width 80

 

[dopehead]

Not remarkably simple i think , you followed the guide on cisco.com and that should work, one thing you should check is whether or not you get a private ip address on the pix or if it is a public ip you are assigned, cause if it's private then your isp nat's your remote pix which is no good with legacy ipsec in most cases. Try figuring that out or work around it by enabling udp-encapsulation of ipsec with this cmd : "isakmp nat-traversal 30"

Jan


Network Systems Engineer
CCNA/CQS/CCSP/Infosec

 

[paulgami]

Hmm.. The remote pix plugs straight into a cable modem but I'll ask the user to "show ip address outside" after the pix has received an IP. I take it that's what you meant - to make sure it's public.

Are there any drawbacks to using "isakmp nat-traversal 30" regardless of the outcome of the public/private ip issue?

 

[paulgami]

Forgot to ask - on which pix should I set the "isakmp nat-traversal 30" command? I assume the remote pix but does the local pix need to know explicitly or will it find out from the type of packets it receives.

 

[dopehead]

No drawbacks, only advantages. The pixes both have to have the command for it to work, the software vpn clients will figure out themselves if they should run nat-t or legacy ipsec.

Jan


Network Systems Engineer
CCNA/CQS/CCSP/Infosec