Ontap Vif miscellany

A few things about networking on a FAS2050.

The FAS2050 has two ports per controller: e0a and e0b. There is a management port (with a wrench symbol) but I can find no trace of this from the software side of things.

From controller 1 I deleted all the vifs so that I would have to learn to recreate them via SSH. On the switch each port that the Netapp is plugged into is configured as follows:

interface FastEthernet0/2
 switchport trunk allowed vlan 100,302,303
 switchport mode trunk
 spanning-tree portfast

I decided that I ought to aggregate the two ports so I ran this command:

vif create multi dennis e0a e0b

The multi could have also been "single" or "lacp". Multi and LACP are forms of aggregation whereas single is an active / passive arrangement. I could have also added a "-b" switch to specify the type of balancing (IP, port, MAC or round robin - I think IP is default).

I then created the VLANs to correspond with the switch port settings:

vlan create dennis 100 302 303

I then decided I didn't need VLAN 302 and 303 for this test:

vlan delete dennis 302 303

Finally, I had to assign an IP address to the new interface. Hence:

ifconfig dennis-100 10.10.10.54 netmask 255.255.0.0

BSOD Special Edition

Client PCs at my company mysteriously reboot every now and again. I decided to try and decipher a dump file.

Before I begin, credit to this guy:

http://weblogs.asp.net/owscott/archive/2012/07/18/reading-a-memory-dmp-or-other-dmp-file.aspx

And in fact, I can't really improve in what he says so I will simply reproduce what he says:

1. Install the debugger
2. Browse to the installation directory in a cmd
3. Type kd –z [path to dump file]
4. Type .logopen [path to log file.txt]
5. Type .sympath srv*c:\symbols*http://msdl.microsoft.com/download/symbols
6. Type .reload;!analyze -v;r;kv;lmnt;.logclose;q

The contents of the dump file will be written to the log and the console window. Read it and solve the problem. Or don't, because in this case the dump files pointed to the graphics card but that turned out to be only a factor and not the entire problem..

Cisco Miscellany

interface FastEthernet2/0/1
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 100
 switchport mode trunk
 switchport voice vlan 2
 srr-queue bandwidth share 10 10 60 20
 srr-queue bandwidth shape 10 0 0 0
 mls qos trust cos
 auto qos voip trust
 spanning-tree portfast trunk

What does this mean?

Interface (port) running at 100MBs of identity Switch 2 / Stack 0 ?? / Port 1 has the following characteristics:

It is a trunk and its encapsulation is 802.1Q. Its native to VLAN 100 but will accept traffic from other VLANS too. It is configured to handle traffic from VLAN 2 (i.e. VOIP devices) differently that other traffic. This is shown with the bandwidth shaping and bandwidth sharing.

Each interface has 4 queues (this is known as egress queuing). You can specify what share of the bandwidth by issuing it a ratio of the total bandwidth. So srr-queue bandwidth share 10 10 60 20 would assign 60% of the bandwidth to queue 3.

The shaping command works differently as it denotes a percentage. Queue 1 in the output above will only be able to use 10% of the bandwidth.

The lines containing QoS relate to prioritising the VOIP traffic. The COS identifier (a value originating from the header of frames) is used to identify VOIP traffic which is then given priority over data frames.


It looks as though the VOIP traffic uses queue 1 because it is shaped and allows for "smoother" traffic flow.

Useful links:

https://supportforums.cisco.com/thread/165677