Networking

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Networking is the process of connecting computing devices, peripherals and terminals together through a system that uses wiring, cabling or radio waves that enable their users to communicate, share information and interact over distances. Often associated are issues regarding operating systems, hardware and equipment, cloud and virtual networking, protocols, architecture, storage and management.

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Hello Experts,
One of our customers has this imaging software to take x-rays installed in a win10 pc
this software stores all its images were taken in a folder on another win10 pc

But I do not see any mapped folder or shared folder
so how is it possible for this software to access the folder on the other pc?

Regards,
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I am trying to route traffic between a 172.x.x.x network to 192.x.x.x. We have Sonicwall routers in place. I understand a little about routing but I need some assistance with this setup. What should I do??
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I have a site that uses a Cisco Wireless Lan Controller.  We have 3 access points that attach to the controller.  The controller is not set up as the DHCP and all the access points have static IP's.  About a month ago, the wireless devices were dropping their connection and no one seem to understand why.  Once the connection was dropped, the user could connect wired and get back on and then I would put a static IP into the wireless adapter and the computer worked fine.  I noticed every time I made this change, I would get the standard message that there were multiple networks connected.  I later discovered that the WLC was also sending out IP's.  I turned that feature off and the devices now connect to the correct DHCP server which is set up on the router.  I am still having the issue with devices dropping connections and I noticed that the DNS IP address is set to 127.0.0.1.  I have no idea why that is being changed.  I have checked my router and that is fine.  I have checked my WLC and everything appears to be fine.  No one has access to this device but me and I don't see any setting that would cause this.  Any thoughts?
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I'm trying to use Wireshark to troubleshoot a network connectivity issue.

The environment:
Windows Server 2016
Wireshark v3
The server has 3 physical NIC's

To start with I decided to do a ping test that works (i.e. gets replies) so that I could view a working ping before then moving to the ping test that is failing

The issue that I have is that while I'm able to capture packets, none of the captured activity is reporting my ping activity?

So I highlight the capture interfaces (see image)
start the ping (172.16.2.1 -t) - which gets replies
run the capture for 10 seconds
then when I try to filter the results based on the host (ip.addr == 172.16.2.1)
nothing is displayed?

So my questions are

1. What am I doing wrong with the capture
2. I'd like to be able to use a display filter of (ip.addr == 172.16.*) - however this is not accepted. Can I do this, and if so, what is the correct syntax?

ThanksCapture interfaces
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On a Netscaler MPX v11.x is it possible to see the bandwidth being used by a particular VIP?
How about for a particular SNIP?
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Looking at our DNS records I see some that have a timestamp with a date & time other's that just say "static" is this showing the last time the particular IP was used?  When removing a machine from Domain & adding it back is it necessary to delete the entry in DNS then recreate it?
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VM Unable to ping gateway.
Can ping VM host
VM host can ping gateway
Windows Server 2012 R2
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I have a DC that opens ADUC VERY slowly. The reason is that I have it on several networks, and one of those networks does not connect to Active Directory- it runs backups, but not during times I would use it for AD-related tasks. I know how to force the backup software to restrict itself to this network... but how do I get Server 2012R2 to limit Active Directory traffic to a specific interface or subnet?
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I have a device which communicates with the computer over a serial port. It communicates using PPP over TCP/IP.

To get from the serial COM port to the network, we create a modem of type "communicate directly between two computers" associated with the COM port. Then we create a network adapter associated with the modem. Then we are able to communicate with the device using its IP address. (IPv4)

Now i want to intercept the PPP frames somewhere along this path, modify the To/From IP address, and reinject the packet somehow. Do this for traffic in both directions.

I can write a user program that opens the serial port and performs I/O with the port. I can read and parse PPP frames coming from the device, extract the IP datagram, modify the IP address, calculate a new checksum, and then... Then I'm not sure how to inject the modified frame back towards the network.

I'm also unsure how to intercept PPP frames headed in the other direction, going to the device.

I've been looking into writing device drivers. (I wrote a device driver eons ago for a VMS computer.) Not sure what device driver to write. I see callout drivers, filter drivers, maybe create another virtual COM port I can inject the stream back into.

I need a deeper understanding of how these device drivers get connected together and pass data back and forth. How does a modem device driver communicate with a COM serial port driver and a network adapter driver?

Maybe the serial port isn't the best …
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Need an HDMI switch for two inputs to one output

I have one display and two computer, a MacBook and a Windows PC. So, I am looking at this device, since it gives me an option to even add a third PC:

https://www.amazon.com/HDMI-Switch-GANA-Splitter-Supports/dp/B06VX1PKQ7/ref=sr_1_5?crid=M9U1NQQMCPCT&keywords=hdmi+splitter+2+inputs+1+output&qid=1551739548&s=gateway&sprefix=hdmi+splitter%2Caps%2C188&sr=8-5

My MacBook uses a Thurderbird port with a converter to HDMI.

My questyion is whether I would be imposing any capacity limits that could impact responsiveness on the display.

There arwe other options here, but I like the idea of three inputs and one output.


https://www.amazon.com/s?k=hdmi+splitter+2+inputs+1+output&crid=M9U1NQQMCPCT&sprefix=hdmi+splitter%2Caps%2C188&ref=nb_sb_ss_i_5_13

Thanks
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Trying to do a port range forward on an ASA and I am having a lot of issues getting it to work.  I have tried everything i can think of, to the point where i am throwing in the towel and just creating individual nat rules (there is over 100 entries), but when i did all the commands I found out that a network object can only have one rule at a time, so there is no simple way of building the commands.  In the past when i had to do something like this it just flat out would not work, but that was on an ASA running 8.3 or below, so there were no network objects and I could build 60 or so commands in excel and have the rules ready to go in about 5 minutes, not the case here as i would have to create over 100 network objects and put a command for each port on each one, and that's just crazy.  There has to be something i'm missing as this is a basic feature on pretty much all other firewalls.

I have been at this for days so I can't list all the things i've tried, but ask me if I've tried it and i should be able to tell you yes or no.  To try and get the port range forward to work what i have been doing is creating NAT rules and using service objects.  The asa takes the command but when i try to connect to the port it fails and in the logs it says the packet is discarded.  I have tried every variation I can think of on the NAT rule and I have tried mirroring (copying) it to a working network object nat rule to no avail.  Surely there is something i'm missing as other people have …
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Recently we migrated to a new service with AT&T which gave us more bandwidth and increased connectivity but today when I come in our Email server is not sending out emails but is receiving emails. We are running an Exchange 2010 server and I have gone out to Network Solutions and changed our mail.<domain name>.com A record and updated our MX record which I checked using DNS Checker which comes back with the correct A record and the MX record is seen but I still cannot send out emails. I am currently trying to get our PTR record confirmed/changed but don't understand why my emails are not going out.

I made some test emails the day we did the migration and they were received by my outside email and when sent back to my work email I received them however one went into spam and the other in my inbox. I know it takes time to propagate on the internet but it has been 3 days and still I am having issues.

What can I check or do to fix this issue?
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Need to VLAN a flat network.  
I currently have a network and it is one large flat network with one subnet of 255.255.252.0 with a range of IP's 192.168.0.1 - 192.168.3.254.
All of my servers, routers firewalls, printers , copiers  and switches are within 192.168.1.1 - 192.168.1.254
My Workstations (Windows 10 )  are all receiving IP addresses from DHCP server and in the range of 192.168.2.50 - 192.168.2.250

I have been tasked with setting up vlan's for the entire network to improve security and performance

I currently have a 5 switches which are all 48 port switches and in  a stacked configuration with 40 GB uplink to a "Central" Switch. These 5 switches are considered our user segment which has workstations and Printers connected.

The Central switch is actually two 48 port switches that are stacked and have the Servers, routers and firewall connected.

my default gateway is a cisco Switch .

I'm looking for some guidance in multiple areas,
1. design ? how many Vlans , do I use vlan 1 ? I think my current configuration would mean everything is VLAN 1
2. Will I need to change my IP addressing of my enire network ? if so what would my new IP addressing look like. how would I g about changing without taking down the whole network.
3. Can the job be done slowly ?
4. Can a server ( DHCP ) on one Vlan provide IP Addresses toWorkstations on a separate Vlan ?

Thanks for any feedback
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I am having replication errors between 2 - DC's on the same local LAN.  I get the following errors:  Replication error 1722 The RPC server is unavailable

I notice this issue when I was adding a couple new computer to the domain and the computers were unable to log into network because of a missing computer account.  The computer account was listed in AD on one DC... but not the other.   I ran some tests... please see attached.

Windows 2008 R2 Domain
Windows 7 / 10 workstations
NLTEST.TXT
DNSTEST.TXT
dcdiag.log
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Folks,
I have a question for all of you security and network people. First a story.
Being the IT department for a small to mid size business has many challenges. Security being paramount.
Having fire-walled, locked down, and through continuous monitoring of my network. After putting out training and explaining the threat landscape we face, I began to feel a slight decrease in my tension level. Only slight mind you.
Imagine my dismay when I discovered that two of the 3 global admins (given that role because they are principals and demanded it) had installed on my domain machines an apparently popular piece of Shareware which I will not name. Just a screen capture, markup, cast and share application that is always phoning home on port 80.
After sending out several scathing emails at midnight and ALMOST resetting every password, I decided the damage was done and cleanup could begin in the morning.
Calling in at 6:00 am to start that process I got push back from the Owner. "I have been running that program for 2 years!!" he says. "What is the problem?" he says.
At which point I began to verbally abuse the man I have been employed by for 20+ years. Now the question.

Did I over react?
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Understanding BGP

in the topology below, I would like to know if an IGP (OSPF.EIGRP,RIP,etc...) has to be configured  between R4,R5,R6 , before R5 advertise eBGP Routes learned from R4 to R7 (AS5700)
Or IBGP between R4,R5,R6 is enough to get that accomplished.

Thank you


BGP
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I am trying to connect a new workstation to a Windows 2008R2 network.  The DHCP server assigns an IPV4 to the workstation.  I can see the server in the network, but if I try access the server I get a "device or resource won't accept the connection" error.  The operating system on the new workstation is Windows 10 PRO, version 1803.

I have cleared the check box for IPV6 on the network adapter properties, and still cannot either access the server or join the domain.  I have ran the prefer ipv4 over ipv6 from " https://support.microsoft.com/en-ca/help/929852/guidance-for-configuring-ipv6-in-windows-for-advanced-users " and still have the same results.  When I try join the domain I get an error that "a domain by that name cannot be found"
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What does symbol mean in the following sentence: More advanced versions of PSK can encode multiple bits per symbol.

From "CWNA Certified Wireless Network Administrator Official Deluxe Study Guide: Exam CWNA-106."

PSK in this context means: Phase-Shift Keying
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I have a small network (single server) running Windows Server 2012r2.

I am looking at the output from the server ipconfig /all and I am confused about the DNS settings that are being reported.  One network card is showing DNS to be 127.0.0.1 and the other one ::1

I was expecting them both to be using IPv4 and both using 127.0.0.1.  Is the NIC1 wrongly configured ?
adapter_config.jpg
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Hello Experts.
I am having a tough Friday.
I have a client with an old exchange 2010 server and a new exchange 2016 Server.
The old server is supposed to be just holding space because I am unable to remove it.  all email boxes are on the new server.

This environment has been working for over 2 years.

Today, we moved the office to a new location.  Same firewall (sonicwall).  Nothing changed on the internal network.

Now I am unable to send email from one internal email address to another.  There is nothing in any queue.  No rejections.
External email does not work either.  Again, no queue, no NDRs.  But let's just focus on one thing and maybe the other will work itself out.

Exchange 2010 installed on Server 2008 R2 - This server has issues looking for an old domain controller?1? (again, this has been working in the exact same configuration for several years.)
Exchange 2016 installed on Server 2016 standard.
I am going through troubleshooting but this is going to be a time sensitive issue very soon.

If I try to telnet to the exchange 2016 server and send an email to a local user, I get an invalid address, 501 5.1.3

Let me know what other information is needed.  every user seems to be able to log into their exchange account fine using outlook on the local network or OWA from outside the network.  they are just not able to send/receive email.
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Experts,

I am looking for a best way to harden my networking environment. I inherent a  Cisco environment and is looking for some recommendations or best  steps to make my environment safe.

Thanks,
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First of all, if this problem gets too involved I will split it out into multiple questions as we conquer one problem at a time.
I recently acquired a used Dell R710 server.  
The system had a system board replacement right before I acquired it, and I did s secure wipe on the drives to remove old software and proceeded to start reloading it.  I'm not extremely well versed in Server systems, and even less so in Dell, so forgive my ignorance as you attempt to help m.
I loaded Server 2016 on the system via DVD and this resulted in some missing drivers, as you might expect.  When I started trying to hunt down drivers I found the suggestion that I should upgrade the bios as well as the iDRAC and LCC.  
   I'm not all that familiar with iDRAC or the LCC, so I spent some time reading up and attempting to upgrade these.  I did finally get the iDRAC upgraded to the latest version, but have been unable to get the LCC firmware updated.  The updates I've attempted, via the iDRAC, remotely from within my LAN, have just sit and spin and tell me that the file is being uploaded, and days later it never changes.  
   I tried accessing the LCC using F10 on bootup, and this has proven futile. I did manage to access it once, but was unable to navigate to the updates that I had on my network share, and while I was in there I noticed some errors in the logs about new hardware installed, such as the ram, processors, etc.... this was a result of the new mainboard being installed, and I found …
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I have a VM (Windows Server 2016 R2) created from a Hyper-V server running NIC Teaming. The server in question can see the internal network on its virtual NIC but cannot surf the Internet no matter how I configure the NIC. Even when I add other virtual NIC's to the server, I still can't get to the Internet. The NIC reads 'unknown network'. All other VM servers on this same Hyper-V server and using the same NIC Teaming works fine and can connect to the Internet.
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What the heck, trying to set a VPN connection on a new MacBook Pro 7th gen. and VPN into a Linksys LRT224
On the Mac I go to network and create a VPN L2TP and use the following settings
Configuration: default
Server Address: (I use my ip address)
Account name: (I use the VPN account I set up on the Linksys)

Authentication Settings:
User Authentication: (I use the VPN account password I set up on the Linksys)
Machine Authentication:
Shared Secret: (Not sure about this so I just used the VPN account password)

Advance settings:
I tried "Send all traffic over VPN connection"

I get e message that the VPN server cannot be reached

I set this up on a Windows 10 and 7 PC and it works just fine
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I don't think 30 seconds is really that long to load a program but anyway....  a customer has a small 2016 Essentials network. Only 4 users. The workstations are I5-7500 with 8GB memory and SSD drives. Windows 10 Professional. The server is more then adequate. Everything works fine except one program. This one program will not load consistently. Some times it takes 3 seconds and other times 30. No sign of CPU usage or memory problems. No excessive traffic. Tonight it was just one user on. Nothing else happening. Same story. Sometimes 3 seconds to load other times 30. My guess is some ling of cache going on. It is not internet based. Any clues?
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Networking

94K

Solutions

67K

Contributors

Networking is the process of connecting computing devices, peripherals and terminals together through a system that uses wiring, cabling or radio waves that enable their users to communicate, share information and interact over distances. Often associated are issues regarding operating systems, hardware and equipment, cloud and virtual networking, protocols, architecture, storage and management.