Networking Protocols Solutions

Question by

phoffric

2019-11-18Solved

REST-like queries run very slow if fetching only 3 records at a time

On internal intranet the C/C++ client sends out REST-like queries via TCP/IP and receives an XML response from the Java server. If the REST query loops fetching 3 records at a time, the total time to accumulate 90000 records is about 10x longer than if we fetch 100 records at a time. We will be performing a number of timing tests to isolate the cause. In anticipation that the problem may be the slow TCP/IP start due to initial small windowing, what settings are there to tell TCP/IP to start off with the largest (or larger) window size possible?

We are on 64-bit RHEL servers, and I assume that since the client/server are run on an intranet self-contained within the company, that we do not have to be concerned about congestion.

Thanks,
Paul

12 Comments

Introduction to R

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R is considered the predominant language for data scientist and statisticians. Learn how to use R for your own data science projects.

Dear Experts

I am looking for the best practice network design to connect 03 offices which is 3 different locations with secured links with redundant links. Below explained
Data center where business applications are hosted in the location 1 here the business applications which are web-based applications, windows AD for authentication, file server, email server are maintained, cisco 1010 FTD and Cisco FMC is in place and two ISP’s.
Location 2 which is far of distance is going to be connected to location 1 data center with MPLS VPN link and for redundancy broad band link planning for SD WAN solution. Finalized and implementation is in progress.
Now that all the employees who were so far working in location 1 that is at data center location to be shifted to the location 3 which is of little distance from location 1. However, we are not shifting data center and our employess are of 20 users who is going to work from location 3 and they have to login for authentication to location 1 where the windows AD and file server for their document store and business application they use CRM.
1. Please suggest the best network design to connect location 3 to location 1, should I have to plan for MPLS VPN as one link and secondary link as leased line and use SD WAN solution here or any other best practice please.
2. How much bandwidth would be needed between location 3 to location 1 for web-based and store documents in the folder
3. as we have 20 users is it required to setup …

6 Comments

Hello we enable these setting to disable NTLM completly in our network.

Im testing it and one problem i got is that when im trying to connect in RDP from a non domain pc (WIndows 10 1903) to my domain pc (WIndows 10 1903) it's not working

I get this error

If i do the same thing from my domain join pc (windows 10 1903) to my non domain join pc (Windows 10 1903) i get the same error but if i add an exception in the GPO above it's working

I also have a problem accessing the \\IP_OF_PC\C$ folder when NTLM is disable

Can we fix that ?

Thanks !

4 Comments

LVL 2

Question by

amigan_99

2019-11-01Solved

Advertising eBGP a subnet from a larger block

Client has a /16 and wants to advertise a /24 within the /16 via a new carrier at one of their smaller sites. Are there any things I need to discuss with the current carrier or the new carrier to make sure the new peering doesn't interfere with the existing route advertisements? Any other gotchas to consider in this operation? Thanks!

2 Comments

Hi, we use haproxy with round robin on a few servers which works amazingly well
However now we need to use it for tcp sessions from different ports

basically, gps iot devices create connections to our server via TCP
When I run a netstat, I see lots of devices sending data from same IP address but different port
here is a snap shot
TCP myServerIp:9001 141.86.25.16:60046 ESTABLISHED
TCP myServerIp:9001 141.86.25.16:62084 ESTABLISHED
These are not the same device, they are using a mobile/cell network with same IP but different ports

So I would need a configuration for HA proxy to route to different servers based on IP and PORT
All the examples I’ve seen so far just use IP, which would not work well for me as it would batch a bunch of devices to same server.
I guess it would work, but it may overload one server and under-load another (if that makes sense)

Something else i’m not sure about, some devices also send data using UDP, and these would also need to be routed to same server, not sure if this would work or if i would just have to route all UDP devices to 1 server

Any feedback, pointers and help appreciated
Thanks

4 Comments

LVL 13

Question by

HuaMin Chen

2019-10-22Solved

Issue to telnet

Hi,
Port 25 is open but I've got the following. Any advice?

C:\Users\Administrator>telnet localhost 25
Connecting To localhost...Could not open connection to the host, on port 25: Connect failed

48 Comments

First, I'm a novice with SSIS, having mostly just maintained existing packages. I have a project that I upgraded from SQL Server 2008 R2/Visual Studio 2008 to SQL Server 2016 (deployment model) in VS 2017. All of the packages work running locally on my machine just as they always have, with the exception of one.

This loops through oledb source servers using a connection string built by variables received from a query. Then it starts the control flows, which each has a series of data flow queries. The weird thing is sometimes it runs fine. Most of the time I get errors like this:

[NetComply - CollectionMembers [212]] Error: SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005.
An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "Protocol error in TDS stream".
An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "Communication link failure".
An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "TCP Provider: An existing connection was forcibly closed by the remote host.
An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "Communication link failure".
An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005

…

6 Comments

I use "Remote Desktop Connection" from my windows PC to connect to remote Linux Virtual Machine running Ubuntu 18.04.2 LTS.
I open terminal window and type following command to clone git repository:

git clone git://git.yoctoproject.org/poky_local_copy

The response is as follows:

I open Mozilla Firefox Web Browser, enter git.yoctoproject.org and connect. Why Web Browser connects to this site but from terminal cannot connect to this site?

5 Comments

Hello,

I've been given two servers for a PHP project inside my company (one for PHP and the other for MS SQL) but my local system administrator has never dealt with remote SQL connections (yeah, I know).

I've managed to use his admin session (thru Skype's desktop presentation) and configured the SQL instance to use a fixed port instead of dynamic (to avoid headaches in the future). I've also created an inbound rule in the SQL server's firewall that allows that same TCP port for the domain. I didn't create an inbound UDP rule for the SQL Browser because I'm not using a dynamic port.

Also, the user that I'm using in my PHP script was created under Security -> Logins but within the database, instead under Security -> Logins for the entire SQL instance. It was created as dbreader and dbwriter only.

This is how my PHP connection looks like (the x are IP address and NNNNN is the port):

$servername = "xxx.xxx.xxx.xxx\\INSTANCENAME, NNNNN";
$connectionInfo = array( "Database"=>"MY_DB_NAME", "UID"=>"loginname", "PWD"=>"somepassword" );
$conn = sqlsrv_connect( $servername, $connectionInfo );

if ($conn) {
     echo "yup";
} else {
     echo "nope";
}

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What else can I try to make the connection happen?

BTW, both sqlsrv and pdo_sqlsrv extensions are loading fine in PHP.

Both servers are Windows Server 2016 and SQL is also 2016.

Thanks in advance!

3 Comments

BGP Configuration with and without another IGP

in the topology below, I would like to know if :

-- BGP needs to be configured on R1 R2,R3,R4 without any other IGP (OSPF)configured on the same routers.
-- Or BGP can be configured only on R1 and R4, but IGP (OSPF) should be configured on all 4 routers R1,R2,R3,R4

Thanks

5 Comments

Python 3 Fundamentals

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

Question by

jskfan

2019-07-21Solved

OSPF Address-Family

OSPF Address-Family

I have seen in some examples EIGRP configured with address-family ipv4 vrf <VRF Name> autonomous-system <AS Number>
However I have not seen examples where OSPF is configured with address-family ipv4 vrf <VRF Name>

for instance, in the topology below Customer Edge CB_1 uses OSPF and it is connect to PE_1

Thanks

4 Comments

Hi, I ran this wireshark network protocol analyzer with no programs open, including no background programs. I ran it for three minutes. I have the report in csv and in pcapng format.(I've changed the latter to a .txt extension to upload).

Can someone let me know if there's any odd network activity going on? Thanks. If you need more information, let me know, this is way over my head.
packet-dissection.csv
packets---Copy.txt

7 Comments

Naive Question on the Bandwidth versus Throughput

EE Members / Gurus ,

Need your help to clarify the definition

1. If i hear in a meeting , client has internet link of 40Mb . Does this means his bandwidth is 40Mb or the throughput ?
Does this 40Mb in case if it is bandwidth inclusive upload/download speeds ie 20/20

2. What does the terminology means ' ' pipe can handle 80Gb of traffic ' . Does this mean the backbone / backplane speed can or should handle this traffic

Regards,
Sid

15 Comments

LVL 1

Question by

philb19

2019-07-08Solved

CIFS slows to a crawl

NFS on netapp filer - very slow only when over a hop

hi out of the blue. - juniper in the core CIFS has slowed to crawl off a netapp - engineer did put a route in but only in prep for a change - it seems from that point on NFS browse to the netapp is soo slow its unusable
we since removed the route - but its just as bad no difference
dont even know if what he did was related

anyway if you are on the same subnet as the cifs netapp filer (eg on a server in the same subnet )CIFS performace is fine!!!
as soon as a hop to get to filer cifs share - its hopeless

Netapp 8.3 data on tap - Juniper core switched HELP

2 Comments

Connect 2 Networks that use Different Routing Protocols.

I would like to know in the case we have 2 separate Networks , one runs OSPF and the other one runs EIGRP. If I need those 2 networks to be able to talk to each other without using Redistribution nor MP BGP, would that be possible? for Instance using VPN GRE Tunnel or IPSEC VPN Tunnel ..

Thank you

5 Comments

Question by

Eric

2019-06-28SolvedPrivate

Help in Analyzing PCAP files

I need to analyze PCAP files and APIs for an MVNE I am working with. I can definitely see some things in the PCAP files they sent, but I would like to be able to do a lot more and more deeply analyze it. I have been using wireshark to break it down but what is the best way to attack analyzing these files. Is there a resource out there, program, best practice, etc.

6 Comments

I am attempting to configure VOIP multicast paging for a member school district. Currently, when a phone page is initiated, the green speaker light on the phone comes on and the mic red (mute) light comes on at same time.However, the page is not able to be heard on any phones. I am told this did work at one time but no one seems to be clear when it stopped working. As of yesterday, I upgraded their WAN switch and I am attempting to get the paging to work again.

Specifics.

Cisco Informacast server (Handles paging) is located on the WAN and is directly connected to a vlan 110 port (near-end)
VOIP phones are located at the district on the far end of our WAN (far-end)

Near end switch connected to Informacast server on vlan 110:
HP 5412R , J9851A running KB.15.17.0007

Far end switch hands all vlan 110 VOIP traffic off to VLAN 72 (Phones):
Aruba 3810M, JL071A running KB.16.07.0003

Vlan 110 is configured on both switches and vlan 72 is only configured on the far end.

Obviously, the config is non-working (copied over from old switch) and has been modified in an attempt to resolve the issue but I will post for reference and advice on what to change.

near end switch vlan 110 config:
vlan 110
name "VLAN110"
untagged A3,B5-B6
tagged
A4-A9,A11-A19,A21-A22,A24,B1,B4,B7-B8,B13-B22,C1-C24,D1-D24,E1-E24,F1-F22
ip address 10.201.0.1 255.255.248.0
ip igmp
ip igmp forward A1,A3-A24,B1-B2,B4-B8,B10,B12-B22,C1-C24,D1-D24,E1-E24,F1-F22
qos priority 7
forbid B2
…

5 Comments

LVL 87

Question by

CEHJ

2019-06-10Solved

Mysterious redirection(?)

There seems to be some sort of mysterious redirection going on when i try to access the site at
http://fostamells.technojeeves.com/

A static file, such as http://fostamells.technojeeves.com/license.txt comes out fine but the attempt to access the homepage seems to land on a page of the company that hosts technojeeves.com. I really can't see why. Is it Wordpress doing this or what (after all it does say X-Redirect-By: WordPress)? I've attached a wget debug log of the attempt to get the homepage
wp.log

12 Comments

I have a scenario where I need a load balancer
When a new tcp connection is initiated from the client, the load balancer much assign a server, and always route all traffic from that that to the server it initially picked

When I netstat, I see and ipaddress and port for the client. (connection) so it makes sense to use this as the identifier for that client

Is there any software in exisitance to do this? Or do. I need to write my own?

3 Comments

Rowby Goren Makes an Impact on Screen and Online

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Learn about longtime user Rowby Goren and his great contributions to the site. We explore his method for posing questions that are likely to yield a solution, and take a look at how his career transformed from a Hollywood writer to a website entrepreneur.

ASBR Without Valid Area

I have noticed when I redistribute connected subnets on OSPF Stub Area I get the message below :

R3(config-router)#redistribute connected subnets
R3(config-router)#
*May 20 21:12:59.726: %OSPF-4-ASBR_WITHOUT_VALID_AREA: Router is currently an ASBR while having only one area which is a stub area

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However OSPF will still take that command as shown below:

R3#sh run | sec ospf
router ospf 1
 area 1 stub
 redistribute connected subnets
 network 192.168.23.0 0.0.0.255 area 1
R3#

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So any one can explain the meaning of that message ?

Thank you

7 Comments

ABR in Stub area not blocking External Routes

In the topology above I have configured R2 area 1 as stub the same for R3
R3 is blocking External Routes E2 and injecting IA default routes, but R2 is still allowing E2 [External routes]

R2#sh run | sec ospf
router ospf 1
 area 1 stub
 network 192.168.12.0 0.0.0.255 area 0
 network 192.168.23.0 0.0.0.255 area 1
R2#

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R3#sh run | sec ospf
router ospf 1
 area 1 stub
 network 192.168.23.0 0.0.0.255 area 1
R3#

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R2#sh ip route ospf
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override

Gateway of last resort is not set

      7.0.0.0/32 is subnetted, 1 subnets
O E2     7.7.7.7 [110/20] via 192.168.12.1, 00:41:55, Ethernet0/0
      9.0.0.0/32 is subnetted, 1 subnets
O E2     9.9.9.9 [110/20] via 192.168.12.1, 00:41:55, Ethernet0/0
      11.0.0.0/32 is subnetted, 1 subnets
O E2     11.11.11.11 [110/20] via 192.168.12.1, 00:41:55, Ethernet0/0
O

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…

4 Comments

NSSA Default-Information-Originate

I would like to know the OSPF area type where we use the command NSS Default-Information-Originate

---On Stub area : we configure all routers inside the are with : Area X Stub
--- On Totally Stub : we configure all routers inside the area with :Area X Stub, and the ABR with Area X Stub Non-Summary
---On NSSA area : We configure all routers inside the are with : Area X NSSA
--- On Totally NSSA: We configure all router inside the are with : Area X NSSA and the ABR with Area X NSSA Non-Summary

However I am not sure how we call the area type where we configure :NSS Default-Information-Originate

Thank you

8 Comments

OSPF Routing table not showing OSPF Routes

in the topology above

I have configured ospf on R5,R6,R8,R9 in Area3 , however the OSPF routes show only on R5 and R6 but not for Area3 , R8 and R9 do not show OSPF routes in their table
I can ping between all 4 routers

Though every now and then a message about OSPF Adjacency comes up on the console
*May 17 21:46:07.003: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.99.9 on Ethernet0/0 from LOADING to FULL, Loading Done
but when I run Show IP Route , no OSPF routes show up

R8#  sh ip route
      192.168.99.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.99.0/24 is directly connected, Ethernet0/0
L        192.168.99.8/32 is directly connected, Ethernet0/0
R8#

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R9#show ip route
      192.168.99.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.99.0/24 is directly connected, Ethernet0/0
L        192.168.99.9/32 is directly connected, Ethernet0/0
R9#

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it looks like that there is also Neighborship formed:

R8#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.99.5      1   2WAY/DROTHER    00:00:35    192.168.99.5    Ethernet0/0
192.168.99.6      1   FULL/DR         00:00:33    192.168.99.6    Ethernet0/0
192.168.99.9      1   FULL/BDR        00:00:[code]

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[/code]

R5 and R6 OSPF table does not show the OSPF routes for Area 3 which is the Network 192.168.99.0/24

R5#sh ip …

9 Comments

IP OSPF Network Point to Point on Frame Relay

I have configured IP OSPF Network Point to Point on R1,R2,R3 serial0 Interfaces.

however from R1 , I do not see both neighbors together, it keeps showing sometimes the 2.2.2.2 which is R2 and sometimes 3.3.3.3 which is R3
I am not sure why it is doing this flapping.

Any help will be very appreciated

Thank you

R1#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
3.3.3.3           0   FULL/  -        00:00:38    123.0.0.3       Serial0/0
R1#

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R1#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
2.2.2.2           0   FULL/  -        00:00:38    123.0.0.2       Serial0/0

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I wonder if the reason that neighborship is flapping because all 3 routers are in the same subnet, and Point to point requires that they need to be in separate subnets ?

2 Comments

Question by

LateNaite

2019-05-04Solved

BGP /24 and ISP

I am just curious if every ISPs will accept a /24 subnet for BGP advertisement. If not, is there a way to find out what they do accept and/or who doesn't accept this?

Secondly, we have a primary ISP that is advertise a /16 and on the secondary ISP, we advertised a /24 subnet (that is included in the /16 of the primary ISP) to test speed and throughout..etc to avoid having to bring out the primary circuit.

We're seeing some different throughput when testing with speedtest.net and when changing the server to a local city, we're getting latency error so not sure about this.

The /24 is a local subnet on the second ISP router and I Just advertised this under the BGP statement and we have a default route out with a next hop of our second ISP. The second ISP has a static route for this /24 to us and a default route out to the internet.

Not sure what might be causing some latency errors when changing the speedtest to some local servers. It seems to be fine if we change the server to Seattle, Washington for example and I'm located in SF.

thank you!

6 Comments

Networking Protocols

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