PIX Firewall 525 access list problem

Similar Questions

• PIX 525 access-list

  I know it must be simple, however, I have some difficulty doing that work. I use version 5.3

  I'm trying to block access to the internet at 172.16.39.X. whatever it is on this network should NOT be able to access the internet.

  I use the list of access and access - group commands but I must have some syntax errors or something as there doesn't seem to be blocking access. Could someone provide a concrete syntax for this address with 255.255.255.0 subnet so I can see if perhaps I simply make a mistake in the entry. I am new to PIX so I wouldn't be really surprised.

  Thank you

  Dave

  You can do this in several ways:

  1. you can exclude this your NAT range. This will not allow this range out to the internet.

  2. on your inside interface, apply this rule:

  insideACL list access deny ip 172.16.39.0 255.255.255.0 any

  insideACL ip access list allow a whole

  I hope this helps.

• PIX 501 ICMP access list Question

  According to the book, I have the pix and firewall that I know of dealing with routers and switches access lists define what traffic is allowed outside the network. With pix access lists can only be applied one way, to the interface they enter, not leaving. It's my understanding, but when I do an ICMP command:

  PIX1 (config) # access - list ethernet1 permit icmp any any echo response

  PIX1 (config) # access - list icmp permitted ethernet1 everything all inaccessible

  Access-group ethernet1 PIX1 (config) # interface inside

  This does not work, but if I apply the access group to the external interface it works. I understand why it is like that.

  Thank you

  This works because the pix is not aware of session state for the way icmp traffic that it does for tcp and udp.

  By default, less access to a high to an interface is allowed, unless you have an acl applies to the interface of higer - then only what the acl permits will be allowed. So you can send outbound icmp echo request. However, for the response to be returned, you must allow that explicitly in an acl that is applied on the external interface, because the pix won't allow any outside traffic by default.

  Even for icmp unreachable, although I want to put in custody to be part of the config. Allow only the unattainable due to the ttl expired to facilitate detection of mtu path, not all unachievable.

  Let me know if it helps.

• FWSM firewall context Access-List entry Limitation

  We have recently experienced an error on one of the firewall settings that it has reached the maximum access list entry. Anyone know what is the limit of the ACL entry by context or where can I find the documentaton for her. No work around to this issue? Thanks in advance.

  Hello

  This value changes depending on which version of the FWSM code you run - and Cisco gets not specific on how the FWSM calculates entered ACE to determine the number of entries you have on your own.

  If you run the command (syntax may be different in 3.x code):

  See the np 3 acl County property

  You get a result that looks like this:

  -CLS rule current account-

  CLS filter rule Count: 0

  CLS rule Fixup count: 11

  CLS is Ctl rule Count: 0

  CLS AAA rule count: 2187

  CLS is given rule Count: 0

  CLS Console rule count: 7

  Political CLS NAT rule Count: 0

  County of CLS ACL rule: 3491

  Add CLS uncommitted ACL: 0

  CLS ACL Del uncommitted: 0

  -CLS rule MAX - account

  CLS filter MAX: 3584

  CLS Fixup MAX: 32

  CLS is Ctl rule MAX: 716

  CLS is given rule MAX: 716

  AAA CLS MAX rule: 5017

  CLS Console rule MAX: 2150

  Political CLS NAT rule MAX: 3584

  CLS ACL rule MAX: 56627

  The counts are your real numbers, MAX is the maximum you can have. AAA rules are numbered for how As you can have applied altogether with your orders of "aaa game. For your question, it seems that you should check your 'CLS ACL rule Count' and 'CLS ACL rule MAX' and make sure you get not close to that number. If you are - try to limit the number of host entries (use the networks) where possible and try to use ranges of ports instead of individual ports in your access list statements.

  I'll try to find the syntax 7.x and post here later.

  -Jason

  Rate if this can help.

• PIX 535 and access lists

  Hello

  We have a Cisco PIX 535. By default, traffic on one more secure interface with a lower security level is allowed, what is?

  OK, I have a doubt, I had to define an access list entry to allow a telnet connection between inside and outside. There is no rule against that traffic, but without this rule the telnet connection cannot be established.

  And my question is: why? It is not supposed to be allowed by default?

  Thanks in advance.

  Higher default-> bottom is allowed... However, once you add instructions permit, it is implicitly deny all at the end. So, if you allow ftp and ssl web... so by default, any other traffic is denied and you need to be precise with your permit.

• IOS VPN on 7200 12.3.1 and access-list problem

  I'm in IOS 12.3 (1) a 7200 and have configured it for VPN access. I use the Cisco VPN client. Wonder if someone has encountered the following problem, and if there is a fix.

  The external interface has the access-list standard applied that blocks incoming traffic. One of the rules is to block the IPs private, not routable, such as the 10.0.0.0 concern, for example.

  When I set my VPN connection, none of my packets get routed and I noticed that outside access list interface blocks the traffic. When I connect to the router through VPN, the router attributes to the client an IP address from a pool of the VPN as 10.1.1.0/24. But normal outside the access list denies this traffic as it should. But as soon as I have established a VPN connect, it seems that my encrypted VPN traffic must ignore the external interface access list.

  If I change my external access list to allow traffic from source address 10.1.1.0/24 my VPN traffic goes through correctly, but this goes against the application to have an outdoor access list that denies such traffic and have a VPN.

  Anyone else seen this problem or can recommend a software patch or version of IOS which works correctly?

  Thank you

  R

  That's how IOS has always worked, no way around it.

  The reasoning is to do with the internal routing on the router. Basically an encrypted packet inherits from the interface and initially past control of ACL as an encrypted packet. Then expelled the crypto engine and decrypted, so we now have this sitting pouch in the cryptographic engine part of the router. What do we with her now, keeping in mind users may want political route she is also, might want to exercise, qos, etc. etc. For this reason, the package is basically delivered on the external interface and running through everything, once again, this time as a decrypted packet. If the package hits the ACL twice, once encrypted and clear once.

  Your external ACL shall include the non encrypted and encrypted form of the package.

  Now, if you're afraid that people can then simply spoof packets to come from 10.1.1.0 and they will be allowed through your router, bzzzt, wrong. The first thing that the router checks when it receives a packet on an interface with a card encryption applied is that if the package needs to be encrypted, it is from his crypto ACL and its IP pools. If he receives a decrypted packet when it knows that it must have been encrypted, it will drop the package immediately and a flag a syslog something as "received the decrypted packet when it should have been."

  You can check on the old bug on this here:

  http://www.Cisco.com/cgi-bin/support/Bugtool/onebug.pl?BugID=CSCdz54626&submit=search

  and take note of the section of the security implications, you may need to slightly modify your configuration.

• card crypto access lists / problem if more than one entry?

  Access list for IPSec enabled traffic.

  I've been recently setting up a VPN between two sites and I came across the following problem:

  I wanted to install a VPN that only 2 posts from site A to site B, a class C network

  So I created a list of access as follows:

  access-list 101 permit IP 192.168.0.1 host 192.168.1.0 0.0.0.255

  access-list 101 permit IP 192.168.0.2 host 192.168.1.0 0.0.0.255

  When I applied the access list above to map (match address 101) encryption, I quickly realized that only the first host (192.168.0.1) was successfully encrypted beeing while the other could not. I've been geeting on ipsec debugging errors saying that traffic to 192.168.0.2 denyed by the access list.

  When I changed the access list above with the following

  access-list 101 permit IP 192.168.0.1 0.0.0.255 192.168.1.0 0.0.0.255

  two items of work could successfully encrypted through IPSec tunnel.

  To look further into it, I realized that only the first entry of the IPsec access list has been really tested for the corresponding traffic!

  Is this a normal behavior or a known Bug? No work around for this problem?

  Kind regards.

  If you have ipsec-manual crypto map in crypto ACL, you can specify that an ACE. Check 12.2 docs:

  Access lists for labelled as ipsec-manual crypto map entries are limited to a single permit entry and the following entries are ignored. In other words, the security associations established by this particular entry card crypto are only for a single data stream. To be able to support several manually created security for different types of traffic associations, define multiple crypto access lists and then apply each a separate entrance card crypto ipsec-manual. Each access list should include a statement to define which traffic to protect.

• Access list ID # on a PIX firewall

  Is anyone know what of the identifier access list on a pix firewall?

  Standard IOS = 1-99

  Extended IOS is 100-199.

  SW = PIX?

  There is no "limit" by Word to say in the Pix. These limits are in IOS because they define what 'type' of acl, it's IE APPLETALK, IPX, IP etc etc. Pix IP is therefore not necessary for this type of identification.

  access-list 100000000000000; 1 items

  allow line of the access list 1 100000000000000 ip any a (hitcnt = 0)

  Jason

• How can I clear counters access-list on a pix firewall

  How can I erase the hitcounts on an on a pix firewall access list without resetting the pix?

  It would be clear access-list on a router counters.

  Thanks in advance

  Steve

  access list counters Clear

• problem of access lists

  Hello, I have a problem with PIX Firewall Version 6.0 (1), the problem is:

  I have a pix with interface 3 inside, outside and dmz.

  IP address outside x.x.x.2 255.255.255.248

  IP address inside 200.115.10.10 255.255.255.0

  192.168.6.28 dmz IP address 255.255.255.0

  I need to make an acl where only 3 PC inside access server installed in the demilitarized zone, with a public ip, but the LCD is not working.

  Here is the ACL, but I change the IP addresses.

  access-list 108 allow ip 200.115.10.0 255.255.255.0 172.16.1.0 255.255.255.0

  access-list 108 allow ip 200.115.10.0 255.255.255.0 200.105.10.0 255.255.255.0

  access-list 108 allow ip 200.115.10.0 255.255.255.0 200.105.20.0 255.255.255.0

  access-list 108 allow ip 200.115.10.0 255.255.255.0 200.105.30.0 255.255.255.0

  access-list 88 allow ip 200.115.10.0 255.255.255.0 200.105.10.0 255.255.255.0

  access-list 88 allow ip 200.115.10.0 255.255.255.0 200.105.20.0 255.255.255.0

  access-list 88 allow ip 200.115.10.0 255.255.255.0 200.105.30.0 255.255.255.0

  pager lines 24

  opening of session

  interface ethernet0 car

  Auto interface ethernet1

  Auto interface ethernet2

  Outside 1500 MTU

  Within 1500 MTU

  MTU 1500 dmz

  IP address outside x.x.x.2 255.255.255.248

  IP address inside 200.115.10.10 255.255.255.0

  192.168.6.28 dmz IP address 255.255.255.0

  alarm action IP verification of information

  alarm action attack IP audit

  172.16.1.1 - 172.16.1.254 test IP local pool

  no failover

  failover timeout 0:00:00

  failover poll 15

  failover outside 0.0.0.0 ip address

  IP Failover inside 0.0.0.0

  failover dmz 0.0.0.0 ip address

  history of PDM activate

  ARP timeout 14400

  Global 1 interface (outside)

  Global (dmz) 1 192.168.6.10

  NAT (inside) - 0 108 access list

  NAT (inside) 1 0.0.0.0 0.0.0.0 0 0

  NAT (dmz) 1 0.0.0.0 0.0.0.0 0 0

  (inside) alias x.x.x.5 192.168.6.30 255.255.255.255

  static (inside, outside) x.x.x.6 10.10.70.1 netmask 255.255.255.255 0 0

  static (inside, outside) x.x.x.4 200.115.10.16 netmask 255.255.255.255 0 0

  static (dmz, external) x.x.x.5 192.168.6.30 netmask 255.255.255.255 0 0

  conduct permitted tcp x.x.x.6 eq lotusnotes host everything

  conduct permitted tcp 2x.x.x.4 eq www host everything

  conduct permitted tcp x.x.x.4 eq lotusnotes host everything

  conduct permitted tcp x.x.x.5 eq www host everything

  driving allowed host tcp x.x.x.5 eq field all

  allow icmp a conduit

  driving allowed host tcp https eq x.x.x.5 all

  conduct permitted tcp 2x.x.x.5 eq 21010 host everything

  the public IP address I need to access it from the inside is x.x.x.5

  Hello

  The ACL you provide will always be the same when shorten you it to this:

  access-list 110 deny tcp host 200.115.10.0 host x.x.x.5

  Access-group 110 in the interface inside

  (it wouldn't work well, because the host 200.115.10.0 * watch the zero * probably does not exist)

  Assuming that your dmz has a lower securitylevel then your inside interface, you must remember that if the packages are make from the highest to the lowest level of security the PIX performs the following operations:

  (1) if it is an existing stream, leave the package through

  (2) if it is not an existing stream, see ACL

  (3) if the ACL refuses, then drop the package, if ACL allows, leave package through

  (4) if the ACL does not at all, leave the package through (since it is the high level of low security)

  But I guess that this is not what you want to achieve.

  I think you need something like this:

  access-list 110 permit tcp host 200.115.10.40 x.x.x.5 eq www

  access-list 110 permit tcp host 200.115.10.41 x.x.x.5 eq www

  access-list 110 permit tcp host 200.115.10.42 x.x.x.5 eq www

  access-list 110 deny ip 200.115.10.0 255.255.255.0 255.255.255.0 x.x.x.0

  (assuming that you have a 24 - bit subnet on your dmz)

  access ip-list 110 permit a whole

  Access-group 110 in the interface inside

  This will allow three internal hosts to access the server x.x.x.5 you dmz with HTTP, than anyone else on the 200.115.10.0/24 subnet to the dmz and allow traffic on all the others outside.

  I hope this helps.

  Kind regards

  Leo

• Helps to configure the pix firewall 507e for e-mail access

  Dear experts,

  I called our provider cisco and ask for technical help regarding our current problem as we know on our set-up.

  She told me to convey my concern to the Cisco TAC. My friends told me to post it here under discussion Netpro.

  I am writing today to ask a few questions about my pix 506 firewall configuration.

  To give the implementation Details pls find below and attached seizures of the show tech command.

  We have subscribed the service DSL and Singtel give us 2 addresses valid public IP that is 203.125.100.246 255.255.255.252.

  I used 203.125.100.246 for my external interface of my firewall pix and singtel assign 203.125.100.245 to the DSL router. In this case, we will only use PAT for internet connection.

  Currently he works very well our Mail Server is resided in the Singtel Office having the ip address of 165.21.111.22. Not work that we can receive and deliver electronic mail on the internet, and we can also surf the internet.

  Now we intend to put our mail in our own network server, because sometimes we encounter slowness on receiving and sending emails. Pls check on the IP address below

  Our LAN IP address is 192.168.1.X 255.255.255.0

  default gateway, which is the IP address of the firewall pix inside interface is 192.168.1.1

  The new mail server IP address is 192.168.1.4.

  Here's what I've done so far.

  I created a static mapping for my mail server is here

  public static 203.125.100.246 (inside, outside) 192.168.1.4 mask subnet 255.255.255.255 0 0

  and modify the access list to allow smtp on our networks.

  192.168.2.0 ip access list ACL_OUT permit 255.255.255.0 any

  ACL_OUT list access permit icmp any host 203.125.100.246

  ACL_OUT list access permit tcp any host 203.125.100.246 eq smtp

  ACL_OUT list access permit tcp any host 203.125.100.246 eq pop3

  ACL_OUT list access permit udp any host 203.125.100.246 EQ field

  Access-group ACL_OUT in interface outside

  After doing it... I have loss all the internet connection, the email does not work... so I deleted immediately. because it causes network failure.

  I have rather edit it and create a static map like this.

  public static 203.125.100.246 (exterior, Interior) 192.168.1.4 mask subnet 255.255.255.255 0 0

  and modify the access list to allow smtp on our networks.

  192.168.2.0 ip access list ACL_OUT permit 255.255.255.0 any

  ACL_OUT list access permit icmp any host 203.125.100.246

  ACL_OUT list access permit tcp any host 203.125.100.246 eq smtp

  ACL_OUT list access permit tcp any host 203.125.100.246 eq pop3

  ACL_OUT list access permit udp any host 203.125.100.246 EQ field

  Access-group ACL_OUT in interface outside

  Saw what it did not cause a failure of network or interruption. I thought that it will already work with the config, I keep it and this is the current config now... But when I change the POP and SMTP settings so that it points on 192.168.1.4 which is the new mail server on our LAN. his does not work.

  To this day, we are in a discussion with my boss or not possible to create a static mapping on our new mail server address 192.168.1.4 to 203.125.100.246 which is already assigned as external IP address and is used for PAT.

  We are asking your help to know how to set up our internal mail server statically match our public IP address that is already used for PAT.

  Please check attached the tech release see the.

  Thank you very much!

  I'd appreciate your quick response.

  Your truth.

  Dennis Pelea

  Dennis,

  Can you please send to me your configuration full pix (unscrew sensitive information) to [email protected] / * /

  I am puzzled, why this configuration does not for you. I have several clients who use a public ip address for external intf more than several other services that use this single ip address.

  Thank you / Jay

• PIX firewall problem

  I have two servers, one in pix inside and the other in the demilitarized zone. I wanted to set them up so that they can communicate with routers and switches

  Located outside the pix firewall.

  My inner Server works fine, able to go Internet and able to comminicate with all devices located outside the Pix Firewall. Here is reference configuration

  of insideserver.

  outside_acl list extended access allowed host x.223.188.0 255.255.255.0 172.28.32.50 ip

  outside_acl list extended access permit ip host host x.219.212.217 172.28.32.50

  access-list extended sheep permit ip host 172.28.32.50 host x.219.212.217

  access-list extended sheep permit ip host 172.28.32.50 x.223.188.0 255.255.255.0

  inside_acl list extended access permit ip host 172.28.32.50 all

  But my DMZ server does not work. However, I made the same configuration with respect to the server on the inside. Not able to communicate with outside DMZ server

  network.

  outside_acl list extended access allowed host x.223.188.0 255.255.255.0 172.28.92.72 ip

  outside_acl list extended access permit ip host host x.219.212.217 172.28.92.72

  access-list extended sheep permit ip host 172.28.92.72 host x.219.212.217

  access-list extended sheep permit ip host 172.28.92.72 x.223.188.0 255.255.255.0

  dmz_acl list extended access permit ip host 172.28.92.72 all

  If I create a static entry for your DMZ SNMP server.

  static (edn, external) 172.28.92.72 172.28.92.72 netmask 255.255.255.255

  He starts to communicate with external devices, but stops Internet run on this server. same configuration

  works with the server on the inside, but not with dmz server.

  NAT (inside) 0 access-list sheep

  NAT (inside) 3 172.28.32.0 255.255.255.0

  NAT (dmz) 3 172.28.92.0 255.255.255.0

  Global interface 3 (external)

  Your static entry is bypassing your nat (dmz) 3 entry. You can do NAT exemption instead, as you do to your home

  1. remove the static entry (followed by clear xlate)

  Add - nat 0 access-list sheep (dmz)

  I suggest to use two acl different sheep, one for each interface.

  Ex: nonat_inside

  nonat_dmz

• PIX V6.2 of lists of access and authentication

  We have a PIX 501 internal v6.2 on an intranet and you want to allow some subnets and other IP of specific hosts through high security (inside) to low-security side (outside) without authentication or authorization.

  However, at the same time, we want to authenticate some other users the same path and apply an access of our v2.6 CiscoSecure ACS list.

  We use http authentication.

  How do I combine these two different requirements on the inside interface

  e.g. allowed tcp 10.10.10.2 255.255.255.0 any eq 1022 and

  (if it is authenticated) permit tcp host 10.120.10.1 any eq 8051

  We have a similar setup working on a router using the firewall feature set proxy authentication, the access list has static entries and changes dynamically when users are authenticated with their conditions of access.

  Do not use an ACL on the inside interface to achieve this. Rather, set you ACLs to include authentication for all traffic from this host out.

  Allow Access-list auth_user host ip 10.120.10.1 one

  This means that the user cannot run ALL the traffic out until he receives the authentication. The host can do this by opening a web browser for what anyone outside and giving the appropriate credentials firewall. Or FTP for what anyone outside... Or telnet to what anyone on the outside.

  When the ACS service validates the credentials of the users, pass back the ACL for this user to define exactly what you want and what you want to deny. If you only allow outbound TCP/8501, then all other traffic is implicitly denied. The ACL by user like any other access-list. This will not require an ACL to be bound inside the interface.

  -Shannon

• How PIX cross access lists?

  I'm new with PIX.

  I would like to know how this fw through access lists. I mean, it's in what order it checks the rules. I guess it can be quite an important issue if you want to keep performance with more than 400 rules and a flow of traffic.

  I thank the of for any comment.

  Hello

  the pix treats the ACL from top to bottom. Put the rules used most frequently at the top. After a match, the pix stop processing the ACL.

  Kind regards

  Tom

• Pix access lists

  I am facing convert statements leads on our PIX 520 access lists. Is there a better way to do this will be as little as possible traffic interruption? For example, to create access lists and then remove the conduit, or vice versa?

  Second, is there a priority recommended in order to access list?

  Hello

  This is a very good paper on the conversion of lines to the ACL, also when writing ACL always have your most important ACL on top of the ACL work from the top down. When you make changes to the ACL or static lines always issue the command clear xlate and save with RAM command.

  http://www.giac.org/practical/GSEC/Bill_Donaldson_GSEC.pdf - by Bill Donaldson, GSEC.

  If you want more information/inf, then let me know.

  Thank you / Jay.