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TCP/IP

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Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.

Cisco Network Question:  2 vlans and one Internet connection

I need to set up a guest network for access to the Internet-only.  The network configuration is:
-  COX Internet
-  RTR_FW: Meraki MX64
-  Core_Switch: WS-C2960X-48FPD_L:  LAN-base
-  Distribution_Switches: WS-C3560CG-8PC-S: IP-base

We presently have one external IPv4 address and use 192.168.168.0/24 internally for operations.

The 2960X is a layer 3 capable switch.

Is there a way to route another network VLAN, something like 172.16.168.0/24, to the Meraki RTR Internet connection.  The Meraki is presently port mapping the external address to the 192.168.168.0/24 network with the Default router of 192.168.168.1.  I used a trunk to the Meraki RTR-FW from the 2960X and it works....

Or do I need to add a RTR and use two virtual interfaces?
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Hi All,

i need to listen on port for testing on a windows server. Do anyone know of a utiltiy? i used one before however unfortunetely i didnt keep a note of it.

Regards,
kay
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Today we faced the Email Delay issue on Exchange environment. Emails were delivering with 5 to 7 minutes delay. On investigation, we found following errors on server. It appears from the first error there could be some connectivity issue between the Exchange servers, but both the servers are located on same chassis, the chances of connectivity issue is very low. After restart the issue gone it also shows there was no connectivity issue. What could be the issue?

Error on Server Queue:
{LED=441 4.4.1 Error encountered while communicating with primary target IP address: "Failed to connect. Winsock error code: 10048, Win32 error code: 10048. "Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or deliver failed to all alternate hosts. The last endpoint attempted was x.x.x.x:475]

Warning on Server Log:
TCP/IP failed to establish an outgoing connection because the selected local endpoint was recently used to connect to the same remote endpoint. This error typically occurs when outgoing connections are opened and closed at a high rate, causing all available local ports to be used and forcing TCP/IP to reuse a local port for an outgoing connection. To minimize the risk of data corruption, the TCP/IP standard requires a minimum time period to elapse between successive connections from a given local endpoint to a given remote endpoint.
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How can I completely disable IPv6 from all network adapters on a Windows 7 Pro. computer?  The use this method to roll-out that configuration change to hundreds of computers?  Is there perhaps a script?

What I am looking for is to disable or un-check the ipv6 settings.

ipv6_1
I want it to be grey'd out or disabled.

ipv6_2
According to web page: https://techjourney.net/disable-turn-off-ipv6-support-in-windows-10-8-1-8-7-vista/

I have tried opening a command prompt as administrator and running
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters" /v DisabledComponents /t REG_DWORD /d 0x000000FF /f

Open in new window


But after I run this command I think IPv6 is disabled partly; but, I still see the check mark on the adapters indicating that it is still enabled.  

Question1: How can I disable the ipv6 for all adapters on a windows 7 Pro. PC?  My manager specifically asked me to do the un-check box, to make it look disabled.

Question2:  How can I use that method for a mass deployment to change the config on hundreds of devices?

Question3:  How can I verify that IPv6 is indeed disabled?

Before the registry changes, if I ran an ipconfig all, under "Ethernet adapter Local Area Connection"  I saw
IPv4 Address. . . . . . . . . . . :  ###.##.##.###
Then I saw
DHCPv6 Client DUID. . . . . . . . : ##-##-##-##-##-##-##-##-##-##-##-##-##-##

After the Registry changes, I do not see any reference to DHCPv6 Client DUID. . . . . . . . : ##-##-##-##-##-##-##-##-##-##-##-##-##-##
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In the environment I am supporting for NGO's there are 2 Exchange Servers, an Exchange 2003 and an Exchange 2010 Server. On the Exchange 2010 Server since few days the router address 192.168.1.1 is added to the IP Block List on the Hub Transport Server. Even after disabling IP Block Listing on the Organization Level the router address is added regularly to the IP Block List within Hub Transport on Server Configuration Level. Any ideas how to prevent this. Blocking 192.168.1.1 does really block complete incoming mail traffic.
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Wired users getting 192.168.1.x IP address.  Instead of 10.10.x.x
Not sure what happened.   Not all the users tho.  Any ideas?
ipconfig /renew /release not helping.  
Need some help troubleshooting.
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Hi Expperts,

Using PHP, JS, and/or jQuery, is it possible to detect if the user is using their registered device.

I think that every device world-wide has a unique MAC Address, so I guess maybe my question is how to read the MAC address? However, not of any modem or router, but of the endpoint device (ie-computer, phone or tablet)?

Thank you.
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Hi All,

I had capture the packet within our intranet where I place the sniffing tool at core switch to only capture conversation between all client to one server. I had observer the almost packet was captured is TCP SYN/ACK packet and TCP RST packet. The TCP SYN packet only below then 10% of captured packet. Its is abnormal in happen in this conversation?
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We recently changed a client's subnet from 192.168.1.x to 192.168.71.x.  All is fine, except that we neglected to change one of their devices to the 71.x subnet.  

We're remote now.  If we were onsite, we could change a computer to 192.168.1.x, connect to the device, and change its IP to 192.168.71.x,, then change the computer back.  But we're remote.  

If we change that computer's IP to 192.168.1.x, we lose internet connectivity.  

Is there a way we can still change the computer's IP to 192.168.1.x, but still use the default gateway of 192.168.71.1 to get to the device?  It's looking like we may have to go onsite to do this...

This is a very simple LAN; SOHO router/firewall.

Thanks!
0
Hi

I'm having issues with Cisco Any connect VPN client not allowing remote connections, specifically ports 139-445.  Running port query is showing that there are some ports open but not ones for the IP address assigned to the virtual network adaptor.

We have the old Cisco vpn adaptor running and those ports are ok.

Ideas?

Thanks
0
Our LAN uses 192.168.1.x IP addresses.  One of our vendors has just required us to connect to their VPN, then RDP to one of their computers to conduct business.  Their network also uses 192.168.1.x IP addresses.  Our network is small, so the effects have been minimal, but only by luck it would seem.  Sometimes we are forced to re-login to our own file server, and this is cumbersome and inconvenient.  How can we adjust settings on our end to minimize/eliminate IP address conflicts?  Our networking equipment is SOHO.  One perhaps obvious solution would to change our entire subnet internally, but that just doesn't seem like the best way to proceed.  Advice please?
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Dear Experts

to setup new office what IP addressing is recommended as it is common to use 192.168.1.0/24 but I would like to go for something different and this network will have to be get connected over the VPN from other location and they may be using 19.168.1.0/24,  this new network yet to be setup will have internal dns and dhcp and leased line and mpls connectivity. the total users or end devices within this network will not be more than 75, I prefer other than 192.168.1.0/24 is there a recommend/best  practice in selecting a particular ip addressing for private lan network please suggest,  is it good to go with 192.168.0.1/24 or something like 192.168.100.0/24 or any other ip addressing recommended please suggest.
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HI Experts,

I have some co-workers who are in another office temporarily.  There is existing wifi already in place and also configured through the ports in the offices.  We have permission to use it.  Problem is that our management does not want to plug directly into theres and went out and purchased a wifi router of our own.....

They set it up and are connected to the wifi of this new router but it only works when he is plugged into the wall through his laptop which isn't making any sense to me.

I do not think plugging directly into their router is a option.  

I really don't feel like this is ideal or should be working but I'm not really clear on why, but it just doesn't sound right and I have to get them connected today.

Any suggestions?

Thank you,

Karen
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What are the best methods to translate or determine what an IP v6 address equivalent IP v4 address is?
0
I often need to determine the IP address of printers that are mapped to Windows 10 computer using WSD.

What is the best method for doing this?

Is this IP address stored somewhere within Windows 10 (such as the registry) where it can be looked up?
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If I have 2 domain controllers in 2 different sites and both have IPv6 checked in TCP stack, do I need to define the dynamic IP address in AD Sites and Services?

I had an issue with SYSVOL GPO replication where one of the domain controllers was using the IPv6 address of the other domain controller to access its SYSVOL, but the address was not defined in AD Sites and Services.  I unchecked and did some other things that resolved the issue... but I need to know best practice for this please. thank you.

2018-06-11_1641.png
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Single Server 2012 R2 network w/40 Win7 PC's.  All "appears to function just fine but continually getting DNS - BPA reports "DNS Servers on Ethernet should include the loopback address, but not as the first entry".

NIC is configured:
Preferred DNS Server:  192.168.16.4
Alternate DNS Server:  127.0.0.1

I've tried different combinations of these addresses.  Should I have our ISP's DNS server settings as primary?

I confess I'm no DNS expert, nor do I know anything about actively managing an IPv6 network.  I can find my way around IPv4 and basic DNS functions just fine.

Connection has  “Microsoft Network Adaptor Multiplexor Protocol” unchecked.  Unsure if this is a default setting or if done as part of earlier diagnostics.  Will follow best practices.

Unsure if it is related but all workstations on the network are Windows7 Pro.  Most of them show a yellow exclamation mark on the network icon in the task bar and “no Internet” although the Internet connection is just fine.  I disable IPv6 momentarily and the exclamation mark goes away.  I reenable IPv6 and the exclamation mark stays gone until the next reboot.

Any assistance appreciated.
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Describe what happens at every step of our network model, when a node on one network establishes a TCP connection with a node on another network. You can assume that the two networks are both connected to the same router.

Please include a detailed explanation of the following:

Physical layer
Data link layer
Network layer
Transport layer
MAC address
IP address
TCP port
Checksum check
Routing table
TTL
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I just installed a Sonicwall at a location that just has multiple PC's and wireless hp 8710 printers. I can install the printer with TCP/ip address and print a test page but, documents print half pages and partial lines.

I downloaded new drivers but, the hp software sees the printer but fails to install.

Don't know what i should do. Would really prefer to install by ip address.
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I'm sure this is simple, but I can't remember and I don't have time to figure it out, so...

I have a Windows 10 "All In One" lenovo computer.

The PC needs to connect to a small personal NAS via Ethernet, AND, the only way it can get Internet is Via Wireless.

The PC has both wireless and Standard RJ45...

I just can't remember how to do both at the same time.

Or, am I over thinking things: Just set a common IP for the RJ45 and the NAS , and then connect the wireless and I'm done...

Just not sure, and when I get there to set it up, it'll be too late to figure it out.

Thanks!
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could I have 2 incoming skype phone numbers

can I receive (not send) sms to skype united states phone number
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iphone 6
verizon united states cell phone

how can I forward all calls to another phone number

do I need to use verizon or can I use iphone (no jailbreak. I dont want viruses or errors with jailbreak).
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Ground Phone line number. How can I opt out of receiving text to landline messages.

Do I need to opt out for 1 phone number at a time
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We have an odd issue on one of our IBM i servers. It appears that every Thursday at 5:00 PM - our hand held devices lose connectivity to our IBM i server.  It looks like our services go up and down for about 20 minutes and then stabilize.  If I look at QHST - I see that there are a lot of devices disconnecting - but i don't see the IBM i actually being unresponsive - but I don't know that for sure.  

I was wondering if there was any detailed logs somewhere related to TCP/IP that I could look to verify if the server actually lost connectivity during that timeframe or if OTHER devices connected to it lost the connectivity.  I have included a couple of snapshots of the logs...to show what I am seeing around that 17:00 PM timeframe.

LIT_Log_1.gifLIT_Log_2.gifLIT_Log_3.gif
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Does COMCAST have poor quality phone service?

I switched yesterday from Verizon FIOS to COMCAST and had terrible telephone calls today on the land line.

I think we were sold >100 GPS upload speed. So, I doubt the poor quality is due to a slow internet connection. But maybe the old Verizon FIOS phone number was what they called a POTS line, a Plain Old Telephone Service line. Those were the ones where you cold hear pin drop.

Did I move from a POTS Line to an Internet based phone? And is that the cause of the major drop in quality?

My new modem is...

Xfinity
Dual Band Wifi
802.11.ac

The phone cable goes into the back.

Would an Internet phone do better?

Is there anything I can do?

I really despise having poor phone quality and may go back to Verizon to escape a bad connection.

Suggestions?

Thanks
1

TCP/IP

11K

Solutions

17K

Contributors

Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.