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.

Share tech news, updates, or what's on your mind.

Sign up to Post

Issue with high number of  TCP CLOSE_WAIT socket connections on Hortonwork(HDP2.6.4) NameNodes & Metastore Server.
We frequently have very high number of CLOSE_WAIT  socket connections on hadoop servers, as a result hadoop services are unavailable on Namenode servers. This happen after heavy ingestion of data in cluster. As a result, I need to restart the cluster after re-booting concerned servers.
I tried re-setting  value of several TCP attributes on the servers, but this had not solve the problem.
Using lsop | grep CLOSE_WAIT, I can identified concerned processes which had CLOSE_WAIT socket connections, I killed the concerned process & try to re-start hadoop services but this had also not solve the problem.
I had monitored the servers for number of CLOSE_WAIT socket connections & whenever number of these keep rising , it's point to symptom that the hadoop services on NameNode are going to down in couple of minutes.
Any idea to solve this issue is welcome.
0
Cloud Class® Course: SQL Server Core 2016
LVL 12
Cloud Class® Course: SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

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?
0
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.
0
I am needing a revolving server system that changes IP address once it starts getting hits from sever filters. It needs to be seamless and use the same email address that we establish to send emails out from, but configures a different IP with every 50 to 100 emails. This is what we need to get a marketing job done and the email messages we want to send have to fit the character count specifics and font type. The subject line is the most important and the size cannot exceed X kilobytes for the total email to reach target market.
0
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
0
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?
0
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
0
Hi,

Can you please advise why IP of server is changing like

C:\Users\Administrator>ping 113.255.213.114
Pinging 113.255.213.114 with 32 bytes of data:
Reply from 113.255.218.217: Destination host unreachable.
Reply from 113.255.218.217: Destination host unreachable.

Open in new window

0
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.
0
Cloud Class® Course: Python 3 Fundamentals
LVL 12
Cloud Class® Course: Python 3 Fundamentals

This course will teach participants about installing and configuring Python, syntax, importing, statements, types, strings, booleans, files, lists, tuples, comprehensions, functions, and classes.

Recently, our W2012R2 RDS server has started giving users problems logging in. The message is:
The number of connections to this computer is limited and all connections are in use right now. Try connecting later or contact your system administrator.

I'm having a hard time finding any helpful information on how to resolve this issue other than on desktop versions of Windows.

In a bid to get around this issue, I've opened more ports (HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp 339x), and this has given some temporary reprieve.

It seems to me that the issue is pervasive. By that I mean that the message does not disappear even if existing users log off from their RDS sessions.

This RDS server has been working fine for years, and now, suddenly, this happens.
0
We run a small network with less than 256 devices so we use static IP addressing (IP 192.168.0.1 subnet 255.255.255.0).
We recently expanded our equipment so I changed the subnet to 255.255.254.0 on all existing servers, workstations, printers, switches, routers, etc to accommodate new workstations in the 192.168.1.? range.

Any workstation (new or old) that I change to the 192.168.1.* range has communications problems. Most notably drive mapping on logon and being accessed by remove viewing products like VNC. Each time I change a machine back to the 192.168.0.* range the problems go away.

Any direction on how to troubleshoot this issue would help !
0
Please include the 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
0
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
0
Hello All,

I have integrated Kamailio 4.4 with asterisk 13 LTS and I think its been properly integrated. It also shows me the registered users but when i call from 101 to 102 it gives me the below error

[May  7 12:43:14] NOTICE[19838][C-00000000]: chan_sip.c:25545 handle_request_invite: Call from '101' (192.168.56.103:5060) to extension '102' rejected because extension not found in context 'public'.

I have followed the below for installation and configuration.

http://kb.asipto.com/asterisk:realtime:kamailio-4.0.x-asterisk-11.3.0-astdb

The user database is fetching from remote host in which kamailio has been installed. Users are showing in asterisk node as well

asterisk*CLI> sip show users
Username                   Secret           Accountcode      Def.Context      ACL  Forcerport
101                                                          public           No   No
102                                                          public           No   No

So how can i debug this or is there any clue that what might be wrong. Please find below  the extension.conf details as well.

exten => _1XX,1,Dial(SIP/${EXTEN})
exten => _1XX,n,Voicemail(${EXTEN},u)
exten => _1XX,n,Hangup
exten => _1XX,101,Voicemail(${EXTEN},b)
exten => _1XX,102,Hangup

Thanks and looking forward for some clues from this community

Regards,
Atif Ramzan
0
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.
0
Public IP configuration for two different network. I got error when I assign public ip address on port 1 and 2 with same subnet. 1.1.1.1/24 for port 1 and i got error when I try to set up 1.1.1.2/24 on port 2, "same subnet on port 1" I am using Cisco 1926.  How do I make this work? Any advise?
0
I am getting error 1m ipv4 tcp listen drops
"the number of TCP listen socket drops during the last minute"
Last night i tried to enables https on server with following steps
Added virtual host file but i reverted the changes.
I also executed the following commands: is it efected something on server.
sudo iptables -A INPUT -p tcp -m tcp --dport 443 -j ACCEPTED
sudo lsof -iTCP -sTCP:LISTEN -P
0
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!
0
Cloud Class® Course: Ruby Fundamentals
LVL 12
Cloud Class® Course: Ruby Fundamentals

This course will introduce you to Ruby, as well as teach you about classes, methods, variables, data structures, loops, enumerable methods, and finishing touches.

could I have 2 incoming skype phone numbers

can I receive (not send) sms to skype united states phone number
0
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).
0
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
0
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
0
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
0
I have a law firm client who has a network for his suite of offices covering a whole floor, 192.168.101.x  The firm has two open offices so they leased them to a different attorney and his paralegal.  The lease included 'internet'. Because the main law firm has ample (100x30) capacity (and a limited budget) I tapped the network (as though it were WAN) into a little netgear wifi router (creating 10.1.10.x).  All this worked fine. Because of the double NAT, the 10.1.10.x network has slightly increased latency but it is negligible.

Last week the 10.1.10.x attorney's paralegal contacted me saying that the lease was supposed to include access to the firm's printer/copier/scanning systems (Ricoh, running Nuance software). It was easy enough to create credentials for them to Copy, and I set up a scanning protocol that uploaded their PDF's to BOX.COM. But they want to print large jobs on the Ricoh printers (192.168.101.203 and 192.168.101.205 - everything on the big law firm is Static IP with MAC-ID).

How do I create a printer path on the 10.1.10.x network (two machines, paralegal is Win10, attorney is Mac, both current rev) to 192.168.101.203 and 192.168.101.205?
0

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.