RE: [nv-l] dot1dbridge

[Leslie Clark <lclark@us.ibm.com>]

Thanks, guys. So it looks CAM is the
same as the dot1dBridge forwarding table but in a different table.  I
found CAM in cisco-stack-mib-v1smi.mib:

brouterCamAgingTime OBJECT-TYPE
    SYNTAX INTEGER (0..1000000)
    ACCESS read-write
    STATUS deprecated
    DESCRIPTION
        "The
aging time for the CAM table.  This duplicate
        item is
the same value as dot1dTpAgingTime."
    DEFVAL { 300 }
    ::= { brouterGrp 6 }

It sounds like updating the CAM ageout
will also update the variable that Switch Analyzer wants, causing entries
to be kept in the dot1dbridge forwarding table as well as the CAM table.
We will try it. (That will be at least a week of change control ....)

Francois, this tip was from the troubleshooting
guide. For devices that end up in the layer2 summary report in the section
'unreachable by layer2 segment', when you are sure you have all of the
devices discovered, the problem, they say, is almost always this ageout
problem. I'm not convinced, but I've told the customer that we cannot call
Support until we have tried this recommended setting. They recommend upping
it from 5 minutes to 15 minutes. 

Thanks, guys.


Cordially,

Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking
Detroit

Francois Le Hir <flehir@ca.ibm.com>
Sent by: owner-nv-l@lists.us.ibm.com

10/27/2004 04:22 PM

Please respond to
nv-l

To	nv-l@lists.us.ibm.com
cc
Subject	RE: [nv-l] dot1dbridge

How often does TSA read the dot1dBridge table in the switch ? is it every
15 minutes ?
Where does this recommendation come from and where is it documented ?

Thanks,
Salutations, / Regards,

Francois Le Hir
Network Projects & Consulting Services
IBM Global Services
Phone: (514) 964 2145


                    
                     
                     
          
             "Barr, Scott"  
                     
                     
  
             <Scott_Barr@csgsy  
                     
                    
             stems.com>    
                     
                     
To 
             Sent by:      
           <nv-l@lists.us.ibm.com>
            
             owner-nv-l@lists.    
                     
               cc 
             us.ibm.com      
                     
                     
 
                    
                     
                     
  Subject 
                    
                  RE: [nv-l]
dot1dbridge              
             10/27/2004 04:07    
                     
                   
             PM        
                     
                     
       
                    
                     
                     
          
                    
                     
                     
          
             Please respond to    
                     
                  
                   nv-l  
                     
                     
     
                    
                     
                     
          
                    
                     
                     
          




Follow up from our router guru:

IOS type looks like the following.

csg-gss-sw1(config)#mac-address-table aging-time XXX

So that covers both flavors of the Cisco switch IOS?s


From: owner-nv-l@lists.us.ibm.com [mailto:owner-nv-l@lists.us.ibm.com]
On
Behalf Of Barr, Scott
Sent: Wednesday, October 27, 2004 3:04 PM
To: nv-l@lists.us.ibm.com
Subject: RE: [nv-l] dot1dbridge

Leslie, hope this helps? it?s not the mib variable but will get you closer:

This looks like the command for a CatOs type switch.  It would be
different
for a IOS type switch.

csg-mildc-sw1> (enable) set cam ?

  agingtime                
 Set CAM aging time
  dynamic                
   Set dynamic CAM entries
  notification               Set
MAC address change notification
  permanent                
 Set permanent CAM entries
  static                  
  Set static CAM entries
csg-mildc-sw1> (enable) set cam agingtime ?
  <vlan>                
    VLAN number
csg-mildc-sw1> (enable) set cam agingtime XXX

A show cam agingtime shows each vlan at 300 sec.  Hopefully there
is a way
to change it globally instead of per VLAN.



From: owner-nv-l@lists.us.ibm.com [mailto:owner-nv-l@lists.us.ibm.com]
On
Behalf Of Barr, Scott
Sent: Wednesday, October 27, 2004 2:57 PM
To: nv-l@lists.us.ibm.com
Subject: RE: [nv-l] dot1dbridge

Leslie, I?ve forwarded your question to our router guru.

The key difference is that ARP cache is a media layer mechanism for tying
an IP address to a MAC address. What you are asking about is tying a bridge
number to a MAC address i.e. this bridge has knowledge of this MAC address
on this segment number. When he gives me an answer I?ll post it.


From: owner-nv-l@lists.us.ibm.com [mailto:owner-nv-l@lists.us.ibm.com]
On
Behalf Of Leslie Clark
Sent: Wednesday, October 27, 2004 2:49 PM
To: nv-l@lists.us.ibm.com
Subject: [nv-l] dot1dbridge


Can anyone tell me the proper terminology to use when asking a Cisco guy
to
change the age-out time for the forwarding table in the dot1dBridge mib?
They think I am talking about the arp cache, but I am not. For Switch
Analyzer it is recommended to increase the value from the default of 300
seconds to 900 seconds, and I can tell them the mib variable, but I cannot
give them the command in Cisco-ese.

For clarity, the mib variable is:

iso.org.dod.internet.mgmt.mib-2.dot1dBridge.dot1dTp.dot1dTpAgingTime
.1.3.6.1.2.1.17.4.2

Cordially,

Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking
Detroit