Unsolved

This post is more than 5 years old

3 Posts

17702

February 22nd, 2006 01:00

3324/48 Unable to bind MAC ACL

Hello All,
 
I am little better than a novice at switch configuration so I was hoping I could get pointed int he right direction.  We have two 3324 and single 3348.  The business wants MAC address filtering so that only machines which have gone through a security certification and inventory will be allowed on the network.  They have an older T1 router that dies whenever certain viruses get on the network.  There are a grand total of 130 MAC addresses in my MAC ACL, and I can get the ACL to bind to one fast ethernet port, but I get the HW resource lack error message when I try more than that.  I though over 200 ACEs were allowed per fast ethernet port so I am not sure what the issue is.  Here is my config in case it may help someone to help troubleshoot this issue.  I have cut out the majority of the ACEs for brevitys sake:
 

port storm-control rate fastethernet 100000

spanning-tree mode rstp

interface range ethernet 1/e(1-24),1/g(1-2)

spanning-tree portfast

exit

interface range ethernet 1/e(1,6,9,12,14,16,24),1/g(1-2)

spanning-tree cost 100

exit

interface range ethernet 1/e(2-5,7-8,10-11,13,15,17-23)

spanning-tree cost 19

exit

interface ethernet 1/e1

speed 100

exit

interface range ethernet 1/e1,1/g(1-2)

duplex full

exit

interface range ethernet 1/g(1-2)

speed 1000

exit

interface vlan 1

ip address 192.168.1.102 255.0.0.0

exit

ip default-gateway 192.168.1.1

no qos

mac access-list kappa

permit 00:11:11:3b:5d:c6 00:00:00:00:00:00 any vlan 1

permit 00:08:a1:1e:a7:f3 00:00:00:00:00:00 any vlan 1

permit 00:12:10:52:0b:1b 00:00:00:00:00:00 any vlan 1

exit

hostname "Basement 24 Port"

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

Any help with this issue would be greatly appreciated!

Regards,

James.

 

February 22nd, 2006 14:00

Can you get a log of the session and show me the command you used to apply the ACL to an interface and the resulting error?  It might help me figure out the problem.
 
Also, looking through your configuration, I notice potential problems that I just wanted to point out.

I notice you are setting the port configuration to fix speed and duplex.  This may cause serious problem in your network unless you are certain that both side of the links are configured to the same speed/duplex setting.  If you configure the port on this switch to fix but the other switch is configured as auto-negotiation (especially if the other side of this connection is in a provider network and you have no control of it or is the other side is a NIC on a workstation where you cannot change the setting to also be fixed instead of auto), then it is more then likely then you will end up with a duplex mismatch on your network - likely on the side that is configured as auto-negotation.  If this happens you will start to notice very poor performance at first then eventually total link failure may occur.  This is a very typical problem in the network.  It is incorrect to assume that if you force the configuration on one side and if the other is set to auto-negotiation that the other side will correctly negotiate to the same speed you configured.  Instead by standard definition if one side is configured to fix speed/duplex and the other side is setup to auto-negotiation, the auto-negotiation will actually link up to correct speed but half-duplex instead.  This is a very bad problem to have.

BTW for this particular problem you are trying to solve - namely only allowed specific MAC into the switch on a given port, it might be easier to use the "port security" feature on the switch to do that - look at this section: <ADMIN NOTE: Broken link has been removed from this post by Dell>

The way you want to do this is first to allow the switch to learn all the MACs for all the system you want to allow on (make the end system send some message - ping or whatever to cause the switch to learn the MAC).  Once you get them on the switch ("show bridge address" will show you what was learned) then lock the port so that it will no longer learn any new address (use "port security" command).  After that you can add new MAC statically to the port using the "bridge address" command and remove the MAC you don't want using "no bridge address" command.  Once you enable port security only known fixed MAC will be allowed (you actually can setup your policy using these commands - see the section above).

Cuong.

3 Posts

February 23rd, 2006 00:00

Hi Cuong,

Many thanks for your help.  I wiped out the switch and reloaded the latest BIOS on it:

332448-1206.dos

Unfortunately I am still having the same problem.  I created the ACL in the line console via hyperterminal with the:

console(config)# mac access-list kappa

I then copy and pasted in my master MAC list of 130 entries.  They look like this int he original document:

permit 00:00:c5:85:4b:cc 00:00:00:00:00:00 any vlan 1
permit 00:0f:1f:b4:2c:14 00:00:00:00:00:00 any vlan 1
permit 00:0d:56:e8:4c:d5 00:00:00:00:00:00 any vlan 1
permit 00:e0:b8:70:71:ac 00:00:00:00:00:00 any vlan 1

I slowed down the line speed to 1500 ms to make sure that no entries were misentered.  After that I did:

console(config)# int eth 1/e1
console(config-if)# service-acl input kappa
console(config-if)# exit
console(config)# int eth 1/e2
console(config-if)# service-acl input kappa
console(config-if)# exit
console(config)# int eth 1/e3
console(config-if)# service-acl input kappa
Can't apply kappa to interface 1/e3, due to lack of HW resources
console(config-if)# exit
console(config)# exit
console# show interface access-lists
Interface        Input ACL
---------        ----------
1/e1             kappa
1/e2             kappa

So not only does it fail to apply on 1/e3 but I verified that a network card that isn't in my master MAC list can still hit the router, which is connected to 1/e1.  I know this because it is able to get an IP address via DHCP.  Below is my saved config file (with the MAC addresses and password info excised again) in case that is of use to you:

spanning-tree mode rstp

interface range ethernet 1/e(1-24),1/g(1-2)

spanning-tree portfast

exit

interface range ethernet 1/e(1,3,5,7,9,11-12,14-15,18-22,24),1/g(1-2)

spanning-tree cost 100

exit

interface range ethernet 1/e(2,4,6,8,10,13,16-17,23)

spanning-tree cost 19

exit

interface vlan 1

ip address 192.168.1.102 255.255.255.0

exit

ip default-gateway 192.168.1.1

mac access-list kappa

permit 00:00:c5:85:4b:cc 00:00:00:00:00:00 any vlan 1

permit 00:04:23:4d:8a:02 00:00:00:00:00:00 any vlan 1

exit

interface range ethernet 1/e(1-2)

service-acl input kappa

exit

 

Thanks again for your help and I appreciate you taking the time to look over these things.  Unfortunately using the MAC learning bridge may not work for us as we have mobile users that will use different ports throughout the day.  I appreciate any suggestions though.  Have a good night.

Regards,

James.

3 Posts

February 23rd, 2006 12:00

Ah, obviously the ACL applied to 1/e1 (the port directly attached to the router) wouldn't block traffic TO the router as the ACL is being applied for INPUT not OUTPUT.

February 23rd, 2006 14:00

Hi, I investigated this problem and one of my colleague told me about a known ASIC limitation on this switch which will prevent you from actually applying the documented 248 ACEs per FE port.  Apparently there are multiple banks of ports: FE ports 0-7, FE ports 8-15, FE ports 16-23, GE port 24, and GE port 25 which are actually sharing the ACEs rules and masks.  Each table has 128 entries (123 are usable) and 16 masks (12 are usable).  Because of this limit the switch ASIC actually doesn't allow you to configure as many ACEs per FE as would theoretically be possible on this design.

As for using the "port security" function.  I think you can still use it.  I'm assuming that you do know the set of all MACs that the mobile users will be using?  Even if you were using ACL you would still need to know all those MACs correct?  So with ACL you were trying to setup a list of MACs and apply them to each port.  Using the "port security" feature you would add the fixed MACs to the ports on which they would enter.  For the mobile MACs which I assume were much less then the 130 MACs you mentioned.  You can either add all those mobile MACs even if they were not always active to the ports to which they would connect if they were active; or if that doesn't work, then for the smaller set of mobile MACs you can go ahead and create the ACL with those MACs and add them to the ports.  So you may be able to work around this problem using both "port security" (for the static MACs) and ACL/ACEs for the mobile MACs (assuming there are much less mobile MACs).

Cuong.

0 events found

No Events found!

Top