One more look at your question produced another thought.
Don't we have to use port numbers in HEX ? In your case it should be "match 
field TCP dest-port 0x16" for SSH port 22

Secondly, in your particular task, Kings, can't we make do with just one 
class-map of stack type by matching the source address and TCP port as follows:

Class-map type stack match-all IP-TCP-STACK
   Match field IP protocol eq 0x6 next TCP
   Match field IP source-addr eq 4.8.6.0 mask 255.255.255.0
   match field TCP dest-port eq 0x16 next IP

As far as I understand you don't have to look into the payload of the packet to 
match for more regex or bits. Then your policy-map would reference this 
class-map and the default class-map would drop everything else

Eugene

From: Kingsley Charles 
<[email protected]<mailto:[email protected]>>
Date: Wed, 2 May 2012 21:17:05 +0530
To: 
<[email protected]<mailto:[email protected]>>
Subject: [OSL | CCIE_Security] FPM to restrict vty access

Hi all

The task asks to allow ssh only from 4.8.6.0/24<http://4.8.6.0/24> and the 
restriction is that we should not use access-lists. So FPM is the only answer.

In the following config, class-map get's matched and 
4.8.6.0/24<http://4.8.6.0/24> is allowed in. The issue is that I need a 
wildcard class-map to block other ssh connections. But that doesn't
work in the following solution.


class-map type access-control match-all telblk
 match field TCP dest-port eq 22

class-map type access-control match-all vlan6
 match field TCP dest-port eq 22
 match field IP source-addr eq 4.8.6.0 mask 0.0.0.255

class-map type stack match-all tcp
 stack-start l2-start
 match field ETHER type eq 0x800 next IP
 match field IP protocol eq 6 next TCP


policy-map type access-control ssh
 class vlan6
 class telblk
   drop

policy-map type access-control tcp
 class tcp
  service-policy ssh

control-plane
 service-policy type access-control input tcp


The following two alternative class-maps also doesn't work

class-map type access-control match-all telblk
match field  ip source-addr  range 0.0.0.0 255.255.255.255

class-map type access-control match-all telblk
match field  ip source-addr 0.0.0.0 mask 255.255.255.255





With regards
Kings
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