Need some advice on learning networking

[blackcat4866]

Re: Need some advice on learning networking

The company I was working for at that time allocated 2 hours included IT setup time, everything after billable at $150 per hour. With few exceptions, every setup had somebody who wanted just one more thing ... and you don't really have to charge me, do you? =^..^=

[BillyCarpenter]

Re: Need some advice on learning networking

The company I was working for at that time allocated 2 hours included IT setup time, everything after billable at $150 per hour. With few exceptions, every setup had somebody who wanted just one more thing ... and you don't really have to charge me, do you? =^..^=

Back in the day when I was a tech for a big Sharp dealership, I made sure I carried a bunch of the service manager's business cards with me. He was also one of the 3 owners. When I got into a confrontational situation with a customer, I would just tell them that this is above my paygrade and hand them his business card.

[M94]

Re: Need some advice on learning networking

I didn't mean to come across as saying there are folks on here that I don't trust. I make it a point to read your posts and try to learn from your experience.

With that being said, I know all too well how costumers try to take advantage. I have a PhD in that.

You didn't at all I was being sarcastic, careful trying to learn from my experience... As far as copiers that experience is VERY limited...
I'm pretty good at customer's and consumer pcs and software though

[BillyCarpenter]

Re: Need some advice on learning networking

You didn't at all I was being sarcastic, careful trying to learn from my experience... As far as copiers that experience is VERY limited...
I'm pretty good at customer's and consumer pcs and software though

I was out of the office equipment game for MANY years. I'm probably one of the least knowledgeable folks on this site. But I'm learning.

[BillyCarpenter]

Re: Need some advice on learning networking

Here's a funny story when I was a new tech. I will never forget it.


I went out on a service call and the pages were almost solid black. It was an old Sharp desktop copier. You actually poured the toner straight out of the bottle into the toner hopper. Anyone remember those? Well, after about an hour of chasing my tail, I look in the copier cabinet and see an open bottle of Xerox toner.

Back in the day, Sharp toner had a sweet smell to it. I opened the toner hopper of the copier and smelled the toner. It wasn't Sharp toner. I vacuumed out all of the Xerox toner, ran a bunch of sky shots, poured in the right toner and I finally got it to making good copies.

This was a contract customer and I wrote them a bill for labor and gave it to some lady. At that point the owner came out of his office madder than hell. He told me that one of our techs was out there a few days ago and put the Xerox toner in the machine. The tech that was out there was one of our top techs and I told the owner that I find that hard to believe. That was a mistake. He became irate. I thought we were gonna wrestle.

He called one of the owners and said that I had called him a liar. My service manager asked me what I said. I told him that I told the owner that I found it hard to believe that one of our techs put Xerox toner in his machine. The onwer look at me said: "basically you did call him a liar". And he was right. Never did that again. I was about 18 at the time.

[slimslob]

Re: Need some advice on learning networking

Here's a funny story when I was a new tech. I will never forget it.


I went out on a service call and the pages were almost solid black. It was an old Sharp desktop copier. You actually poured the toner straight out of the bottle into the toner hopper. Anyone remember those? Well, after about an hour of chasing my tail, I look in the copier cabinet and see an open bottle of Xerox toner.

Back in the day, Sharp toner had a sweet smell to it. I opened the toner hopper of the copier and smelled the toner. It wasn't Sharp toner. I vacuumed out all of the Xerox toner, ran a bunch of sky shots, poured in the right toner and I finally got it to making good copies.

This was a contract customer and I wrote them a bill for labor and gave it to some lady. At that point the owner came out of his office madder than hell. He told me that one of our techs was out there a few days ago and put the Xerox toner in the machine. The tech that was out there was one of our top techs and I told the owner that I find that hard to believe. That was a mistake. He became irate. I thought we were gonna wrestle.

He called one of the owners and said that I had called him a liar. My service manager asked me what I said. I told him that I told the owner that I found it hard to believe that one of our techs put Xerox toner in his machine. The onwer look at me said: "basically you did call him a liar". And he was right. Never did that again. I was about 18 at the time.

All laser units use a write to no charge. That way for laser on time is limited by the % coverage. Where the problem can come in is that some makes charge the drum negative and some charge it positive. I have even seen negative when the wrong toner has been poured toner with the wrong properties in.

[KenB]

Re: Need some advice on learning networking

The company I was working for at that time allocated 2 hours included IT setup time, everything after billable at $150 per hour. With few exceptions, every setup had somebody who wanted just one more thing ... and you don't really have to charge me, do you? =^..^=

[KenB]

Re: Need some advice on learning networking

All laser units use a write to no charge. That way for laser on time is limited by the % coverage. Where the problem can come in is that some makes charge the drum negative and some charge it positive. I have even seen negative when the wrong toner has been poured toner with the wrong properties in.

[BillyCarpenter]

Re: Need some advice on learning networking

I remember seeing that back in the analog days, too.

Normally, it would be with the wrong brand of toner, but sometimes even with so-called “competitive” supplies, which claimed they were for the model in question.

Yep. The copier I was talking about in the previous post was an analog.

[BillyCarpenter]

Re: Need some advice on learning networking

I've been playing around with WireShark. I'm able to capture data and filter and it's starting to make sense. All the things that we've talked about in this thread I'm able to actually see....the session layer being started, the protocols , ports used, ect., ect.


That's a start. Hopefully, one day I can use it to actually troubleshoot SOMEthing.


PS - One cool thing I did was scan to my PC while wireshark was running and then filtered the data by the copier IP address. It's interesting to see all the data.

[slimslob]

Re: Need some advice on learning networking

Or the dispersant had gone sour.

[BillyCarpenter]

Re: Need some advice on learning networking

I stayed up very late last night learning how to use WireShark. You can use WireShark for many different applications but since I'm in the copier business I decided to concentrate on SMB as it pertains to WireShark.


What I discovered is that in order for WireShark to be useful for troubleshooting SMB that I need to understand how it operates on the different layers of the OSI (TCP) model....at least up to layer 4. Anything after that deals with the application layer and that's where it gets really complicated. For most networkers, troubleshooting to layer 4 is enough to fix most problems.

There's a LOT of videos on YouTube that deal with WireShark as it pertains to troubleshooting SMB. I picked one at random and I'll post it below. This particular video is really detailed. The guy started out talking about the very first version of SMB which was developed back in 1984. The earliest version of SMB wasn't designed to be scalable as it dealt with "names" of devices and not IP addresses. That didn't work for large organizations as you can imagine. It also didn't use DNS and had to send out network broadcasts which created too much network traffic. SMB1 had over 100 commands in the early days. SMB1 has seen many changes over the years but the bottom line is that it became outdated and had security risks.

To deal with the problems of SMB1, Microsoft came out with SMB2 & SMB3. Both versions are much less "chatty" than SMB1. SMB1 has over 100 commands compared to SMB2 which has only 19. As you can see, SMB2 and SMB3 are much less complicated and less "chatty."

Other improvements with SMB2 and SMB3 is that both are able to deal with brief network network outages without dropping the session layer. It accomplishes that by something called "Durable File Handles." SMB1 would close the session layer if there was any network outage and the communication process would have to start over again from the beginning.

This post is getting long and I'll end with this:

Microsoft developed SMB2 & 3 to be backwards compatible. It does this thru a negotiating process between the server and client. The server will "down negotiate" with the client down to SMB1.


The video that I was watching was a few years old when SMB1 was still viable. SMB1 is out but for this discussion I left it in because I thought it was interesting.

[bsm2]

Re: Need some advice on learning networking

SMB scanning fails

path is incorrect
port is incorrect
user name or password incorrect
sharing rights and or security rights incorrect

Enjoy your day

[tsbservice]

Re: Need some advice on learning networking

SMB scanning fails

path is incorrect
port is incorrect
user name or password incorrect
sharing rights and or security rights incorrect

Enjoy your day

Seems pretty fair to me - like 99.99%

[tsbservice]

Re: Need some advice on learning networking

I stayed up very late last night learning how to use WireShark. You can use WireShark for many different applications but since I'm in the copier business I decided to concentrate on SMB as it pertains to WireShark.


What I discovered is that in order for WireShark to be useful for troubleshooting SMB that I need to understand how it operates on the different layers of the OSI (TCP) model....at least up to layer 4. Anything after that deals with the application layer and that's where it gets really complicated. For most networkers, troubleshooting to layer 4 is enough to fix most problems.

There's a LOT of videos on YouTube that deal with WireShark as it pertains to troubleshooting SMB. I picked one at random and I'll post it below. This particular video is really detailed. The guy started out talking about the very first version of SMB which was developed back in 1984. The earliest version of SMB wasn't designed to be scalable as it dealt with "names" of devices and not IP addresses. That didn't work for large organizations as you can imagine. It also didn't use DNS and had to send out network broadcasts which created too much network traffic. SMB1 had over 100 commands in the early days. SMB1 has seen many changes over the years but the bottom line is that it became outdated and had security risks.

To deal with the problems of SMB1, Microsoft came out with SMB2 & SMB3. Both versions are much less "chatty" than SMB1. SMB1 has over 100 commands compared to SMB2 which has only 19. As you can see, SMB2 and SMB3 are much less complicated and less "chatty."

Other improvements with SMB2 and SMB3 is that both are able to deal with brief network network outages without dropping the session layer. It accomplishes that by something called "Durable File Handles." SMB1 would close the session layer if there was any network outage and the communication process would have to start over again from the beginning.

This post is getting long and I'll end with this:

Microsoft developed SMB2 & 3 to be backwards compatible. It does this thru a negotiating process between the server and client. The server will "down negotiate" with the client down to SMB1.


The video that I was watching was a few years old when SMB1 was still viable. SMB1 is out but for this discussion I left it in because I thought it was interesting.

I will dig into my memos and find what a member here written some time ago about using Windows buit in
tool "Event Viewer". It covers almost everything you need to troubleshoot SMB problems.

OK i find it.

"Use caution when enabling SMBV1. There is a reason this was disabled. I believe it was the "Wanna Cry" virus. By enabling SMBV1 you are exposing the customer to this risk. Admittedly it seems like there is no other choice when in fact there are fixes. Firmware and other copier settings. Permission settings on the computer.

A tool I have been using recently is "Event Viewer" This is built into windows so it does not require and other installation of software. In the search just top in "Event Viewer" and it will be found. Then scroll through too:
Application and Service Logs
Microsoft
Windows
SMB Section (SMBClient, SMBDirect, SMBServer, SMBWitnessClient)
When you click on each section there is an Audit, Connectivity, Operational, and Security

I have found most of my fixes under SMBServer, Security. Just look at the times and open it and read the errors. If there is communication is reaching the machine usually there will be an error of some kind. Sometimes it makes sense such as communication from SMB1 when SMB1 is disabled. The confusing one comes in to play when the error is related to authentication and you know the login and password's are correct. Then it is a matter of permissions on the computer not being correct someplace. This could be password not meeting security settings, (length/characters), sharing in "Advanced Permissions", etc,...

Sometimes services get turned off with windows updates a few I have found are:
Function Discovery Provider Host


Function Discovery Resource Publication


SSDP Discovery


TCP/IP Netbios Helper


UPnP Device Host


DNS Client


Device Association Service


A couple of the above settings will also keep "Network Discovery" from staying enabled. It can be turned on but then you exit and go back it is off again.

If you run into a problem that everything works and after a very specific time each time check the "ARP" table settings. Had one years ago that after 15 minutes the copier IP dropped out of the Arp table and the copier would no longer email. Tried 5 different copiers and manufactures and customers IT still blamed the copier because they did not want to figure out why on their end. "