Category Archives: General

General Posts

Cisco 7609 10 Gig Link Aggregation

I ran into an interesting problem last week, and I found very little information on the internet about it. I will share it here, in the hope that it will help someone else.

 

Working with a newer product, I created a 10 Gig Link Aggregation configuration on my Cisco 7609 WS-X6708-10GE cards.

Cisco Config

interface Port-channel1
description TA5000 40 Gig LAG
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 10-20
switchport mode trunk
no ip address
mls qos trust cos
spanning-tree bpdufilter enable
spanning-tree bpduguard enable
lacp max-bundle 4
end

When I added the second link to the group, the Cisco kept putting the link into an alternate group!

Port-channel: Po1A
------------

Age of the Port-channel   = 0d:00h:02m:47s
Logical slot/port   = 14/6          Number of ports = 1
Port state          = Port-channel Ag-Inuse
Protocol            =   LACP

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
<  0     FF     Te1/3    Active    8

Time since last port bundled:    0d:00h:02m:45s    Te1/3

I searched the web for any indication of what the A meant on the end of the port-channel group, but I came up empty. All I knew was that my config looked good, and the Cisco would not add the second link into the group. The only thing I could find about this “alternate” group was, “if something on the other end doesn’t match exactly, the Cisco will declare the link in a new group”.

Armed with that little information, the search begins.

Partner Information

Doing a ‘show lacp neighbor detail’ gave me the information I needed to find the issue.

          Partner               Partner                     Partner
Port      System ID             Port Number     Age         Flags
Te1/3     00001,00a0.c8c8.3edd  0x3               0s        FA

          LACP Partner         Partner         Partner
          Port Priority        Oper Key        Port State
          65535                0x1             0x3F

          Port State Flags Decode:
          Activity:   Timeout:   Aggregation:   Synchronization:
          Active      Long       Yes            Yes

          Collecting:   Distributing:   Defaulted:   Expired:
          Yes           Yes             No           No
          Partner               Partner                     Partner
Port      System ID             Port Number     Age         Flags
Te1/4     00001,00a0.c8c8.414d  0xD               0s        FA

As you can see, the System ID’s for each link being reported in the LACP protocol do not match. Now, in this case, this is true, as the end device is in a multi-chassis LAG configuration. In order to work with the Cisco, the System ID’s must match. The Alcatel 7750 does not do this check.

Changing the System ID, allows the lag group to come up.

Port-channel: Po1    (Primary Aggregator)
------------

Age of the Port-channel   = 9d:20h:10m:33s
Logical slot/port   = 14/5          Number of ports = 2
Port state          = Port-channel Ag-Inuse 
Protocol            =   LACP

Ports in the Port-channel: 

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
  0     55     Te1/3    Active            4
  1     AA     Te1/4    Active            4

Time since last port bundled:    3d:17h:48m:54s    Te1/4
Time since last port Un-bundled: 3d:18h:09m:43s    Te1/3
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Creating Easy to Remember Secure Passwords

Creating a Strong password

As our lives continue to move to the cloud, it is more important than ever to maintain strong passwords.

Here I will show you some easy tricks to creating strong and easy to remember passwords.

Diff’rent Strokes

Being a child of the 80’s, I remember Gary Coleman’s popular show called Diff’rent Strokes. His catch phrase, “what you talkin’ about Willis?” is a great start to a strong password.

By creating an acronym out of that catch phrase, we create a unique word that is not in the dictionary, but is also easy to remember.

Password: wytaw

Camel Humps

To make it stronger, we can arrange the acronym with alternating upper and lower case letters. We now have a non-dictionary word with upper and lower case letters.

Password: WyTaW

Add Numbers

Add numbers to make it stronger.

Password: WyTaW1234

Add Special Characters

Add special characters to the password to make the password stronger. In this example, I will add !@#$ which happens to be + 1,2,3,4

Password: WyTaQ1234!@#$

Conclusion

Using this process, we now have an extremely long (13 characters), non-dictionary, contains upper case, lower case and special characters password.

Sure to meet the requirements of even the strictest IT departments.

Use one, any or all of these tricks to create your own easy to remember secure password.

Using Wireshark

If you don’t have Wireshark in your arsenal, download it now.

Wireshark.org

Wireshark, formerly ethereal, has become the defacto standard for protocol analysis. It is open source, so anyone can build dissectors for any protocol. If you use proprietary protocols in your products, you can create your own dissector, so Wireshark will decode just like any other standard protocol.

In a future post, I will show how to use Wireshark to look for packet loss in Microsoft Mediaroom flows without needing the encryption key.

How I Became Known as The Tick

My boss, who I have worked for longer than anyone else in my career, was attempting to bestow upon the crowd at our annual Sales Meeting , the virtues of my performance the previous year. He used the analogy that my troubleshooting skills were like that of a tick, who burrows into the skin in search of blood, that I never stop until I find the root cause of an issue. My coworkers, who show no mercy, immediately latched onto the idea. I decided to own it, and now I am affectionately known as The Tick.

This is my blog.