09-05-2003 07:25 AM - edited 03-09-2019 04:40 AM
Is it possible to interface a PIX 501 directly to a UK ADSL modem? If so is there a configuration example available. Is there a PIX software release pre-req?
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09-06-2003 10:41 AM
Hi Alan,
What you are trying to achive can be done, If you have a IP assigned by your ISP for the ADSL Modem interface (thats if your ADSL modem can be assigned a IP address, if not then router solution is the way to go) then what you need to do is configure the PIX with PAT (Port Address Translation), This way all your inside addresses will translate to 1 public IP address (ISP ADSL Modem IP address). I presume your setup would be something like this:
LAN--PIX501--ADSL(MODEM)--ISP
Here's a example In this example the PIX is directly attached to the ISP, and the ISP has assigned a single public IP address to the PIX, which MUST be used on the outside interface.
The following is the configuration that will allow the PIX to use the single IP address on its outside interface while also using the address to perform PAT for the devices on the inside network.
LAN(192.168.3.0/24)INSIDE_ROUTER(192.168.2.2/24)PIX(inside_e1 192.168.2.1/24)PIX(outside_e0 199.199.199.2/30)---INTERNET
pix(config)# ip address outside 199.199.199.2 255.255.255.252
pix(config)# ip address inside 192.168.2.1 255.255.255.0
!
pix(config)# route outside 0.0.0.0 0.0.0.0 199.199.199.1 1
pix(config)# route inside 192.168.3.0 255.255.255.0 192.168.2.2 1
!
pix(config)# global (outside) 1 interface
pix(config)# nat (inside) 1 0 0
On the above, the nat command specifies that all internal addresses use the address pool configured in the global command for pool 1. The corresponding global command, however, doesnt specify a pool of addresses, but refers to the outside interface. One advantage of this process is that if the ISP is not statically assigning you the public address, but is using DHCP to assign you the address, you dont need to worry about what address is eventually assigned on the outside interface because the interface parameter causes the PIX to use the currently assigned address, whether its statically assigned or dynamically assigned.
Also, when you make any changes (like the above) please remember to do command 'clear xlate' and also command 'write memory'.
You may find the following URL helpful:
http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_62/config/bafwcfg.htm#37288
Hope this helps with your situation, let me know how you get on.
Thanks - Jay
09-05-2003 07:35 AM
Alan,
Answer to your question is yes you can configure a PIX 501 with ADSL Modem. Which PIX IOS have you got on the PIX, do command 'show ver'
Let me know - Thanks,
Jay
09-05-2003 07:47 AM
Alan,
Here's a PIX 501 running IOS 6.2(2) Config example from my lab, this 501 has a 50 user licence and PDM etc. With a ADSL router connected to ISP, i.e. LAN_ROUTER - PIX(501) - ADSL - ISP
Hope this helps -
PIX Version 6.2(2)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password ******** encrypted
passwd ******** encrypted
hostname pixfirewall
domain-name mydomain.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 10.x.x.x test_lab
name 132.x.x.x mydomain.co.uk
name 10.x.x.x TestPC
access-list inside_access_in permit ip host 10.x.x.x host mydomain.co.uk
access-list inside_access_in deny ip host 10.x.x.x any
access-list inside_access_in permit ip any any
pager lines 24
interface ethernet0 10baset
interface ethernet1 10full
mtu outside 1500
mtu inside 1500
ip address outside 10.x.x.x 255.255.255.0
ip address inside 10.x.x.x 255.255.255.0
ip verify reverse-path interface inside
ip audit info action alarm
ip audit attack action alarm
pdm location 10.x.x.x 255.255.255.0 inside
pdm location 10.x.x.x 255.255.255.255 inside
pdm location 192.x.x.x 255.255.255.0 inside
pdm location test_lab 255.255.255.255 inside
pdm location mydomain.co.uk 255.255.255.255 outside
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
access-group inside_access_in in interface inside
route outside 0.0.0.0 0.0.0.0 10.x.x.x 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 si
p 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
aaa authentication telnet console LOCAL
http server enable
http 192.x.x.x 255.255.255.0 inside
http 10.x.x.x 255.255.255.255 inside
http test_lab 255.255.255.255 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
no sysopt route dnat
telnet 10.x.x.x 255.255.255.0 inside
telnet timeout 5
ssh timeout 5
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
username admin password ******** encrypted privilege 15
terminal width 80
: end
Thanks - Jay
09-06-2003 09:12 AM
Many thanks your reply. PIX is running 6.2(2). I have it operating OK behind a DLINK ADSL router which is in turn connected to A DLINK ADSL modem. I would like to eliminate the ADSL router (directly connect the PIX to the ADSL modem) but I cannot seem to get that configuration to work.
I am dynamically assigned an IP address.
I understand that (in the UK) the ADSL router uses PPPoA to negotiate the IP Address and in my version of PIX IOS this does not seem to be supported (only static, DHCP and PPoE).
I may be completely off beam here being a newbie to this ADSL business! So any further responses greatly appreciated.
09-06-2003 10:41 AM
Hi Alan,
What you are trying to achive can be done, If you have a IP assigned by your ISP for the ADSL Modem interface (thats if your ADSL modem can be assigned a IP address, if not then router solution is the way to go) then what you need to do is configure the PIX with PAT (Port Address Translation), This way all your inside addresses will translate to 1 public IP address (ISP ADSL Modem IP address). I presume your setup would be something like this:
LAN--PIX501--ADSL(MODEM)--ISP
Here's a example In this example the PIX is directly attached to the ISP, and the ISP has assigned a single public IP address to the PIX, which MUST be used on the outside interface.
The following is the configuration that will allow the PIX to use the single IP address on its outside interface while also using the address to perform PAT for the devices on the inside network.
LAN(192.168.3.0/24)INSIDE_ROUTER(192.168.2.2/24)PIX(inside_e1 192.168.2.1/24)PIX(outside_e0 199.199.199.2/30)---INTERNET
pix(config)# ip address outside 199.199.199.2 255.255.255.252
pix(config)# ip address inside 192.168.2.1 255.255.255.0
!
pix(config)# route outside 0.0.0.0 0.0.0.0 199.199.199.1 1
pix(config)# route inside 192.168.3.0 255.255.255.0 192.168.2.2 1
!
pix(config)# global (outside) 1 interface
pix(config)# nat (inside) 1 0 0
On the above, the nat command specifies that all internal addresses use the address pool configured in the global command for pool 1. The corresponding global command, however, doesnt specify a pool of addresses, but refers to the outside interface. One advantage of this process is that if the ISP is not statically assigning you the public address, but is using DHCP to assign you the address, you dont need to worry about what address is eventually assigned on the outside interface because the interface parameter causes the PIX to use the currently assigned address, whether its statically assigned or dynamically assigned.
Also, when you make any changes (like the above) please remember to do command 'clear xlate' and also command 'write memory'.
You may find the following URL helpful:
http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_62/config/bafwcfg.htm#37288
Hope this helps with your situation, let me know how you get on.
Thanks - Jay
09-07-2003 07:55 AM
Jay,
Thanks for this, in fact my modem cannot be assigned an IP address (indeed I do have a fixed IP address). So I assume that this is the problem. I also conclude that a pix/adsl modem configuration would not work in a non static IP address context and that an adsl router is always required in this situation.
Alan
09-05-2003 08:32 AM
Do you have ADSL or cable?
If you are behind an ADSL router then I suspect you will be using a statically assigned address on the Outside interface - no problems.
I am still having problems using a PIX501 with a Motorola Surfboard and Telewest Blueyonder. I am now into the realms of quirks in the Telewest Blueyonder network but in two weeks of experiencing and reporting problems to Blueyonder Tech Support I haven't received anything back.
09-05-2003 09:24 AM
Hello Max.. again,
I beleive your problem is with blueyonder but without seeing your config on the 501, can't be 100% so let me have a look at your PIX config and also if you can (if any) config on the blueyounder router.
Pls remember to change 'real IPs' and passwords, if you don't want to post on the forum then send it to me direct at noc1@vodafone.net
Thanks - Jay
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