match protocol http will do the job 

 


Date: Wed, 8 Jun 2011 20:56:00 +0800
From: [email protected]
To: [email protected]
CC: [email protected]
Subject: Re: [OSL | CCIE_Security] Doubts on Zone based firewall

hi Guys

some additional basic doubts...

when it's being asked to inspect http traffic for example, will we need :

- only "match protocol http" ?
- or we need both "match protocol http" and "match protocol tcp" ?

i'm confuse whether tcp or udp always need to be there or not when application 
layer protocol is required to be inspected.

thanks in advance

Regards
KY



On Tue, May 17, 2011 at 7:50 PM, Nick Montante <[email protected]> 
wrote:




I understand your point, Bruno, but the inspection only occurs on the traffic 
matched in your ACL. If you have an ACL matching telnet, and your class-map 
matches this ACL, inspection will only occur for TCP/23. I believe that ZFW 
will identify that traffic as telnet (since it is coming across TCP/23) and 
will inspect it as such.
 
From: Bruno [mailto:[email protected]] 
Sent: Tuesday, May 17, 2011 7:47 AM
To: Nick Montante
Cc: Kingsley Charles; Kok Yong CHEONG; [email protected]



Subject: Re: [OSL | CCIE_Security] Doubts on Zone based firewall




 
Well, If I read "all protocols will be inspected" only wanting to have like 
telnet specifically, I would say that it is for sure something I do not want

I would still go with match protocol xxxx as required. 

On Tue, May 17, 2011 at 8:38 AM, Nick Montante <[email protected]> 
wrote:


My understanding is that a “match protocol” statement is not required; however, 
if you do not match any traffic using NBAR and you only match it in your ACL, 
it will still work as expected but it will throw a warning when configured (and 
at boot) that “no protocol was specified, so all protocols will be inspected”.
 
From: [email protected] 
[mailto:[email protected]] On Behalf Of Kingsley Charles
Sent: Tuesday, May 17, 2011 7:11 AM
To: Bruno
Cc: Kok Yong CHEONG; [email protected]
Subject: Re: [OSL | CCIE_Security] Doubts on Zone based firewall


 
I don't think so. All the above given config should work. "match protocol" is 
not mandatory for a class-map.

With regards
Kings

On Tue, May 17, 2011 at 3:30 PM, Bruno <[email protected]> wrote:
Keep in mind that ZBF requires at least one match protocol statement on 
class-maps. 
With that said, some options you said will not work


 

On Tue, May 17, 2011 at 4:40 AM, Kingsley Charles <[email protected]> 
wrote:
If you are matching the protocol in the access-list, then you need not specify 
"match protocol xxx".


With regards
Kings


 

On Tue, May 17, 2011 at 1:02 PM, Kok Yong CHEONG <[email protected]> wrote:
hi Thank for your input,

for example of smtp, based on your explanation, there isn't need to "match 
protocol smtp " then ? since the access-list already mentioned the port 25 
which also means matching smtp protocol from the access-list ?

my main doubt was that do i need to specify "match protocol xxx" since i've 
already kind of mention it in the ACL with "access-list 122 permit tcp any host 
192.1.1.200 eq 25"



thanks in advance

regards
KY



On Tue, May 17, 2011 at 2:35 PM, Kingsley Charles <[email protected]> 
wrote:
Option A is simple and will work.


Option B can be configured as following in either of two ways:

access-list 121 permit ip any host 192.1.1.100 
access-list 122 permit ip any host 192.1.1.200 



class-map type inspect match-all CM-I-D-SMTP
 match access-group 122
 match protocol smtp

class-map type inspect match-all CM-I-D-WEB
 match access-group 121
 match protocol http 

policy-map type inspect PM-I-D
 class type inspect CM-I-D-WEB
  inspect
 class type inspect CM-I-D-SMTP
  inspect
or 


access-list 121 permit tcp any host 192.1.1.100 eq 80
access-list 122 permit tcp any host 192.1.1.200 eq 25

class-map type inspect match-all CM-I-D-SMTP
 match access-group 122

class-map type inspect match-all CM-I-D-WEB
 match access-group 121

policy-map type inspect PM-I-D
 class type inspect CM-I-D-WEB
  inspect
 class type inspect CM-I-D-SMTP
  inspect
With regards
Kings



On Tue, May 17, 2011 at 11:33 AM, Kok Yong CHEONG <[email protected]> wrote:



hi Guys

I'd like to clear by doubts on ZBF.

a practice question like: configure zone policy coming in from internet to DMZ 
as follows:
1) allow web access to a server 192.1.1.100 located on the DMZ zone
2) allows smtp access to server 192.1.1.200 located in DMZ zone

will the config be (a) or (b) :
(a) access-list 124 permit tcp any host 192.1.1.100 eq 80
access-list 124 permit tcp any host 192.1.1.200 eq 25

class-map type inspect C-I-D
match access-group 124

policy-map type inspect P-I-D
class type C-I-D
inspect


OR

----------------------------------------------------------------------------------------------------------

(b)
access-list 121 permit tcp any host 192.1.1.100 eq 80
access-list 122 permit tcp any host 192.1.1.200 eq 25


class-map type inspect match-all CM-I-D-SMTP
 match access-group 122
 match protocol smtp ------>  why do we still need to mention SMTP ?
class-map type inspect match-all CM-I-D-WEB
 match access-group 121
 match protocol http ------>  why do we still need to mention http ?

policy-map type inspect PM-I-D
 class type inspect CM-I-D-WEB
  inspect
 class type inspect CM-I-D-SMTP
  inspect

----------------------------------------------------------------------------------------------------------

my main doubt for (b) is why do we need "match protocol smtp", since it never 
mentioned layer 7 inspection.  I would expect the access-list is sufficient to 
define the traffic as http traffic already ?  or we need both the acl and 
protocol to make it complete ?

appreciate your effort to enlighten me..  thanks in advance

regards
KY
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com
 
 
 

_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com


-- 
Bruno Fagioli (by Jaunty Jackalope)
Cisco Security Professional
 This communication is the property of ClarkDietrich Building Systems LLC and 
maycontain confidential or privileged information. Unauthorized use of 
thiscommunication is strictly prohibited and may be unlawful. If you have 
receivedthis communication in error, please immediately notify the sender by 
reply anddestroy all copies of the communication and any attachments.


-- 
Bruno Fagioli (by Jaunty Jackalope)
Cisco Security Professional


This communication is the property of ClarkDietrich Building Systems LLC and may
contain confidential or privileged information. Unauthorized use of this
communication is strictly prohibited and may be unlawful. If you have received
this communication in error, please immediately notify the sender by reply and
destroy all copies of the communication and any attachments.

_______________________________________________ For more information regarding 
industry leading CCIE Lab training, please visit www.ipexpert.com Are you a 
CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com         
                               
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com

Reply via email to