Figuring out which device a packet went out on

In trying to triage a NFSv3 READDIR lack of response, I had to figure out which interface a packet was arriving at and which one it was being sent back on. My typical way to invoke tshark is the very simple: 

tshark -i any -w /tmp/f.scp

Everyone else uses a pcap extension and for some reason, I find “f” as a perfectly fine name for a temporary packet capture I don’t plan to keep.

If I used this approach, I could see the READDIR packet arriving and departing, but I couldn’t tell which interface was being used. If I did this instead,

tshark -i bond0 -w /tmp/f.scp

I could see the READDIR call, but not the reply. I then proceeded to cycle through each and every interface, but no joy at finding the reply. (To be honest, I probably went too fast in my iteration and just missed it.)

I read (somewhere via Google foo) that it would print the interface the pack either arrived or departed on. So, I went to back to using “any” and checked:

Frame 72359: 198 bytes on wire (1584 bits), 198 bytes captured (1584 bits) on interface 1
    Interface id: 1 (any)
        Interface name: any

Not what I wanted. Somehow I figured out that I could use -i multiple times to specify the interfaces I wanted:

tshark -i bond1.80 -i bond0 -i eno1 -i bond1 -i bond1.100 -i bond1.2080 -w /tmp/bonds.scp

And then when I looked at the two packets of interest:

Frame 72359: 198 bytes on wire (1584 bits), 198 bytes captured (1584 bits) on interface 1
    Interface id: 1 (bond0)
        Interface name: bond0
...
Frame 72366: 1614 bytes on wire (12912 bits), 1614 bytes captured (12912 bits) on interface 4
    Interface id: 4 (bond1.100)
        Interface name: bond1.100

So now I can in a multi-homed system, I can figure out the interfaces on which packets are captured.

October 9, 2021 by tshark 0

Filtering on NFSv3 procedures

I was asked to figure out why a NFSv3 server was not responding to READDIR requests. Note, I don’t know if this was READDIR or READDIRPLUS. I fired off tshark to capture packets:

tshark -i any -w /tmp/bonds.scp

Hmm, even when filtering on NFS, too many packets to examine (it is a very busy NFSv3 server):

NR_09-20:24:09 pixie ~ $ tshark -r /tmp/bonds.scp | wc -l
Running as user "root" and group "root". This could be dangerous.
140532
NR_09-20:29:13 pixie ~ $ tshark -r /tmp/bonds.scp -Y nfs | wc -l
Running as user "root" and group "root". This could be dangerous.
39350

I could use Wireshark, but nah!

I can use a better filter:

NR_09-20:31:46 pixie ~ $ tshark -r /tmp/bonds.scp -Y "nfs.procedure_v3  == 16 || nfs.procedure_v3  == 17" | wc -l
Running as user "root" and group "root". This could be dangerous.
21

This states to only filter if the NFSv3 procedure is either 16 or 17.

You can find the list of NFSv3 procedures at https://datatracker.ietf.org/doc/html/rfc1813#page-27.

October 9, 2021 by NFS tshark 0

Everyone else is down, I can’t muster an emotion

At work today, everyone else was down and expected me to be as well. I just couldn’t muster any – Mondays are bad after a sick weekend – my sleep is all screwed, my voice is gone (not much talking after most of the weekend in bed), and if the sickness is still around, well, there you go.

So, not much interaction, we all went to lunch, and I just pretty much sat there. Someone asked me about the goings on, and I was just like “Meh.” Nothing personal, but I’m shut down.

Yoga was good – it was a welcome escape from work expectations. But I kept on thinking of things I could do – had to focus on breathing.

And afterwards, found a Depeche Mode playlist on youtube and just finally got an emotion – happy! Supposed to be sad, but they always cheer me up. By the way, I also love Goth Electro: Tribute to Depeche Mode. I guess on youtube: Goth Electro Tribute to Depeche Mode (youtube)

Started to get silly, so on to Rag’n’Bone Man – Human (Official Video).

And finally Gotye – Somebody That I Used To Know (feat. Kimbra) – official video.

The Gotye song is simply one that has come up along the way.

Anyway, music, it does a body good!

January 23, 2018 by Chronic Fatigue 0

3TB Disk

I bought an external 3TB disk and wanted to attach it to an old Airport Extreme. It wouldn’t see the disk. Turns out the disk is formatted for windows.

Okay, Diskutil to the rescue!

Not, I kept getting:

Running operation 1 of 1: Erase “Untitled”…
Unmounting disk
MediaKit reports not enough space on device for requested operation.
Operation failed…

A quick consultation of the Internet Oracle turned up:

MediaKit reports not enough space on device for requested operation.

Okay, but I wanted case sensitive, so:

loghyr:~ loghyr$ diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_APFS Container disk3 1000.0 GB disk0s2

/dev/disk1 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_APFS Container disk2 1000.0 GB disk1s2

/dev/disk2 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme – +1000.0 GB disk2
Physical Store disk1s2
1: APFS Volume EVO1 703.1 GB disk2s1

/dev/disk3 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme – +1000.0 GB disk3
Physical Store disk0s2
1: APFS Volume EVO2 157.6 GB disk3s1
2: APFS Volume Preboot 19.6 MB disk3s2
3: APFS Volume Recovery 506.6 MB disk3s3
4: APFS Volume VM 3.2 GB disk3s4

/dev/disk4 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *3.0 TB disk4
1: Apple_HFS 3.0 TB disk4s1

loghyr:~ loghyr$ diskutil unmountDisk force disk4
Forced unmount of all volumes on disk4 was successful

loghyr:~ loghyr$ sudo dd if=/dev/zero of=/dev/disk4 bs=1024 count=1024
1024+0 records in
1024+0 records out
1048576 bytes transferred in 0.452265 secs (2318499 bytes/sec)

Here is where I differ from the link:

loghyr:~ loghyr$ diskutil partitionDisk disk4 GPT JHFSX MacBackAttack 0g
Started partitioning on disk4
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk4s2 as Mac OS Extended (Case-sensitive, Journaled) with name MacBackAttack
Initialized /dev/rdisk4s2 as a 3 TB case-sensitive HFS Plus volume with a 229376k journal
Mounting disk
Finished partitioning on disk4
/dev/disk4 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *3.0 TB disk4
1: EFI EFI 209.7 MB disk4s1
2: Apple_HFS MacBackAttack 3.0 TB disk4s2

 

January 23, 2018 by Macs tricks 0

And at its worse I am still not lazy, I am sick

So the brain fog is heavy and the final symptom has hit. I’m at work and if it didn’t take caring, I’d go home.

For the past two weeks, the brain fog has been medium and I could tell at yoga that I really didn’t care about being there – despite trying to string together an attendance record.

How to put in words what I feel – how long it took me to realize a fragment of words, forget it, stir through the fog, and come up with enough of the gist of the thought? I want my writing to flow – to appear crisp and effortless. I feel like a shadow of what I am capable of crafting.

I’ve learned to be terse in technical writing and it hampers my efforts in fiction or journaling.

I still don’t care, probably won’t get much done today, it bugs the work ethic I’ve built up in myself, but I know deep down it can’t be helped. This isn’t me being lazy (just added that to the title!), this is me being sick and getting through the day. I worked hard last week and I’ll work hard some more soon. I have to let go of the guilt I am not feeling.

Don’t know how else to put it – there is guilt – but it is floating a layer above my inner critic. He is watching the guilt drift by and he is waving to it. Learning that I am not disassociating the emotion from my upbringing (work ethic) has been liberating. The disassociation is literally the disease, not depression, not an explicit action on my part. If it were depression, I would feel the guilt.

January 18, 2018 by Chronic Fatigue 0

The double whammy

Sometimes I can’t sleep – well actually, I may be dreaming that I can’t sleep. The other night I was convinced I was awake, but I had no clue about the earthquake that struck at 2:30am. But somehow, even dreaming I haven’t slept seems to make me tired.

So the double whammy is loosing sleep and getting the chronic fatigue.

 

January 5, 2018 by Chronic Fatigue 0

When it hits

When it hits, it isn’t fatigue – it isn’t lack of sleep – it is either brain fog or a lack of desire to do anything. The brain fog means I can’t remember simple things. Last night I was trying to say I got essential oils for Christmas. It came out as “not incense, an aroma”. It took me 10 minutes to come up with essential oils in my mind – of course the person I had been talking to was long gone.

And the other symptom is the hard one to talk about – most people confuse it with depression when I try to describe it. But it isn’t that – the best I can come up with is that depression has an emotional context and this symptom does not. I can see however why people confuse it and why researchers might put the blame on the person and not the symptom.

I might act like I care about you or the task at hand – but I don’t. I simply balance an equation in my mind as to whether I care about you or it when I’m not sick. And if I do, then I’ll force myself to take action. And if I can’t force myself to take action, I don’t leave the house.

January 3, 2018 by Chronic Fatigue 0

Exercise (specifically Yoga) and Chronic Fatigue

Two common misbeliefs about chronic fatigue are that

  1. It is mental/emotional
  2. Exercise can cure it.

See Bad Science Has Misled Millions With Chronic Fatigue, Court Order Reveals and For People With Chronic Fatigue Syndrome, More Exercise Isn’t Better.

For me, my adventure began shortly after I started losing weight via walking/running and yoga. I’ve always wondered if that lifestyle change triggered the disorder in me, but I wouldn’t trade the yoga away for the disorder. I don’t have it as bad as most (I think) and my worst days sound like good days to some of the stories I read at https://themighty.com.

But, what yoga does bring me is a barometer to my health. I generally like my yoga instructors and some of them I love, so when I start asking myself why I am in a class, what I am getting out of it, and how long until it is over, I know I am near my worst. My worst? I won’t even go to a class – despite whatever grand scheme I have in place for attendance.

January 1, 2018 by Chronic Fatigue 0