06-04-2007 09:10 AM - edited 03-11-2019 03:24 AM
Hello,
I am setting up 2 PIX 506E's as firewalls. I am not Cisco trained or certified and I'm trying to figure some of this stuff out as I go. Not the ideal situation, but we're a nonprofit without tons of cash for training so there it is.
Anyway, I do have over 20 years in IT so I'm not completely lost, but I am stuck on this particular problem. My 506E will not let me ping the outside interface from the inside interface. It does let me ping the inside interface from a computer on the inside network. I am hoping someone can give me a command to allow pinging the outside interface from the inside network.
I would paste my config here but I'm not sure which parts are relevant and I don't want to go over the character limit.
Thanks.
JP
Solved! Go to Solution.
06-08-2007 06:03 AM
You acl is wrong, you do not refer to the destination by the private ip address.
access-list inbound permit tcp any host 192.168.2.1 eq www
should be...
access-list inbound permit tcp any host 200.1.1.2 eq www
06-08-2007 10:02 AM
no access-group inbound in interface inside
06-04-2007 09:16 AM
Hi JP
You can't do this on the pix at least on version 6.x which you are probably using as a pix 506E desn't support v7.x.
You can ping the inside interface from a machien on the inside and you can ping the outside interface from a machine on the outside but not the outside interface from the inside.
HTH
Jon
By the way, your config would probably not go over the limit and you can always attacj the config as a text file. Just make sure you remove any sensitive information.
06-04-2007 09:32 AM
Thank you, you probably saved me 4 days of reading.
By the way, anyone who can point me to free newbie webcasts (video or audio) or even print courses, I would appreciate it. I belong to IEEE Computer, so I'll be looking there as well.
Just for kicks, here's my config (yes, it's much smaller than I feared, all the networks are internal and please don't laugh at the newbie)
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 acl_outbound permit ip any any
access-list acl_outbound permit tcp any any
access-list outside permit icmp any any
access-list outside permit ip any any
access-list inside permit icmp any any
access-list inside permit ip any any
access-list outbound permit tcp any host 192.168.2.254
access-list outbound permit icmp any host 192.168.2.254
access-list 90 permit ip 192.168.1.0 255.255.255.0 200.1.1.0 255.255.255.0
pager lines 40
mtu outside 1500
mtu inside 1500
ip address outside 200.1.1.1 255.255.255.0
ip address inside 192.168.2.254 255.255.255.0
ip audit info action alarm
aaa-server RADIUS protocol radius
aaa-server RADIUS max-failed-attempts 3
aaa-server RADIUS deadtime 10
aaa-server LOCAL protocol local
aaa authentication telnet console LOCAL
aaa authentication http console LOCAL
http server enable
http 192.168.2.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt noproxyarp outside
telnet 192.168.2.0 255.255.255.0 inside
telnet timeout 5
ssh timeout 5
console timeout 0
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
username administrator password xxxxxxxxxxxxx encrypted privilege 15
terminal width 80
Cryptochecksum:xxxxxxxxxxxxxxxxxxxxxx
: end
06-04-2007 10:46 AM
OK, here's some more of the problem - since I can't ping my external interface, can I ping another address on the same network as that interface? My understanding is that there's no communication from a lower-security interface to a higher-security interface, but isn't internet communication almost always two-way? That's what ACL's are for, isn't it? So could I set up an ACL to allow an ICMP packet through the 506e, or is it ICMP specifically that's not allowed through?
Thanks,
JP
06-04-2007 10:56 AM
"since I can't ping my external interface, can I ping another address on the same network as that interface?"
Yes, you can ping from the inside to something outside the pix with the correct acl to allow the ping reply in the outside interface.
" My understanding is that there's no communication from a lower-security interface to a higher-security interface, but isn't internet communication almost always two-way?"
Yes, there is no communication allowed from lower to higher security levels unless allowed by an acl. Yes, it is two way but the traffic is "initiated" from the inside, not the outside.
"So could I set up an ACL to allow an ICMP packet through the 506e, or is it ICMP specifically that's not allowed through?"
Sure, you already have it in your config...
access-list outside permit icmp any any
only problem is none of your acl's are applied with the "access-group" command.
access-group outside in interface outside
06-04-2007 11:02 AM
Thank you. I did that, and I have the other PIX on the outside network, interface ip = 200.1.1.2. After applying the access-group, I tried to ping that second pix from inside my first pix, and I'm getting a "request timed out". I am able to ping the second pix from the CLI on the first pix. Any thoughts?
Thanks!
06-04-2007 11:06 AM
global (outside) 1 interface
nat (inside) 1 0.0.0.0 0.0.0.0
06-05-2007 10:57 AM
wrong post
06-08-2007 04:32 AM
Thanks for the suggestion, that's exactly what I needed. I am now able to ping other ip's on my outside network. Thanks very much to everyone who helped!
06-08-2007 05:53 AM
Now I have the second PIX set up identical to the first one, but that's not quite right. I want to have a web server inside pix2, able to be accessed by a client on the inside interface of pix1. The outside interfaces of pix1 and pix2 are on the same network, connected through a hub. As I have said before in this post, I can now ping from inside pix1 to the outside of pix2. I have tried to follow directions to set up a static, an access-list, and an access-group to allow access to a web server inside pix2 but I can't access it either from a host on the 200.1.1.0 network (the outside interface network) or from a host on the inside network of pix1. I've pasted my current configs (which are different than the configs from before) and I wonder if anyone has suggestions.
Thanks.
JP
--------------------------
pixfirewall2(config)# sho run
: Saved
:
PIX Version 6.3(5)
interface ethernet0 auto
interface ethernet1 auto
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password xxx encrypted
passwd xxx encrypted
hostname pixfirewall2
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 inbound permit tcp any host 192.168.2.1 eq www
pager lines 24
mtu outside 1500
mtu inside 1500
ip address outside 200.1.1.2 255.255.255.0
ip address inside 192.168.2.254 255.255.255.0
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) 1 0.0.0.0 0.0.0.0 0 0
static (inside,outside) tcp interface www 192.168.2.1 www netmask 255.255.255.255 0 0
access-group inbound in interface outside
access-group inbound in interface inside
route outside 0.0.0.0 0.0.0.0 200.1.1.1 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 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 RADIUS deadtime 10
aaa-server LOCAL protocol local
aaa authentication telnet console LOCAL
aaa authentication http console LOCAL
http server enable
http 192.168.2.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
telnet 192.168.2.0 255.255.255.0 inside
telnet timeout 5
ssh timeout 5
console timeout 0
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
username administrator password xxx encrypted privilege 15
terminal width 80
Cryptochecksum:xxx
: end
-------------------
06-08-2007 06:03 AM
You acl is wrong, you do not refer to the destination by the private ip address.
access-list inbound permit tcp any host 192.168.2.1 eq www
should be...
access-list inbound permit tcp any host 200.1.1.2 eq www
06-08-2007 06:12 AM
Thanks - that did it. Now for the VPN!
06-08-2007 09:56 AM
While I'm at it, if anyone sees anything in my configs that should be removed, I'm accepting comments. Thanks.
06-08-2007 10:02 AM
no access-group inbound in interface inside
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: