Can i use two networks at the same time? - windows

I am developing a program that makes a request to a private IP address, to fetch data, which I can access only by being connected to that network.
And I have a database that is behind a vpn (other private IP), and I need to send that previous data to that database.
My computer is windows 10 and has two network cards, I can successfully connect to each network independently.
But the question is how can I make my computer stay connected to both networks at the same time and the described process works.
I appreciate if anyone can provide me with information on whether this is possible at the operating system configuration level. Or should it be something software development as such?

Related

From WiFi to Cellular 3/4G on ESP32

I am building a project utilizing Wifi on the ESP32 module. Using RTOS, I am running a web server on 1 core and a web client on another core. This works very well and I can access the web server remotely via my browser and the WiFi provided IP address. The Web client reads some sensors and sends the data via WiFi to my database. All good and everything works as desired.
Now I need to do the next step and move beyond the reach of the WiFi and reproduce the same result via 3/4G cellular. I looked at the "easy" solution to use an industrial 3/4G WiFi router and simply keep what I have. Cost of these "industrial" type routers are on the high side, where as 3/4G module which also include a GPS chip are around half or less. Problem is that I cannot get my head around how I will "replace" my current WiFi functionality with one of these modules. The modules seems to expect you to connect via serial (rs232) and using modem AT commands establish a connection to the internet. Question is, after connecting to the internet, how do you continue to have "network functionality" same as with the built-in WiFi? Is there some library that will do ethernet over the serial port? Can I still have the WiFi and the "serial ethernet" running at the same time or switch between the two?
Thanks!

Compress and copy same time to another server - slow

i have a big problem. I need tranfer a lot of files by a server to another server, but the second server isnt a local server. If i tranfer by a local server i cant 100mbs but if i send for another server out the speed is 2mbs. my network is 1gbs. I use a command line 7z.
If your servers are (as you wrote) on the same network and connected through the same line you are most likely to have a network connection problem.
I've often seen that the duplex settings of network cards are not set up correctly which leads to a lot of collisions.
Check your network card settings and try to force for example 100mbps full duplex.
I work for a company where this happens daily when trying to connect IBM network cards with Cisco switches. Have a look here how to set up duplex settings: https://superuser.com/questions/86581/how-do-you-check-the-current-duplex-value-of-a-network-card-set-to-auto-negotiat.
If this doesn´t help you might be better off asking at superuser.com

snmp network discovery identify mac address of device connected to a router

i am working on a network discovery program which employs snmp to discover devices in the network. My program takes the router-ip as input, scans the iprotetable(iprouttenext hop),to determine if any other routers are connected to it. for non router devices (like switch) the algorithm scans the arptable (ipnettomediatable) of the router, but cant find the connected switch unless i ping from the switch to the router. is there any way where i can determine the device connected directly to the router ..?
Getting the devices connected to a router or switch is not that easy. Switches usually maintain a MAC forwarding database where it stores which MAC address has been seen on which switch port. This table can be easily read by using the bridge MIB. Unfortunately, there are several issues to take care of:
Those entries disappear again, when a device to the switch has been switched off or is simply not communicating. Usually, the entries in the MAC forwarding tables age out after 5 minutes or so.
The fact that a MAC address has been seen on a switch port doesn't mean that the device having the mac address is directly connected to the port. There might be any number of other switches, routers or hubs inbetween.
Some manufacturers like Cisco or HP use their own protocols to determine the network topology. There are several protocols (that area usually also available through a SNMP MIB):
CDP (Cisco Discovery Protocol): This is a proprietary protocol developed by Cisco to expose network topology information. Some vendors licensed this technology and implement that protocol in their products.
LLDP (Link Layer Discovery Protocol): A standard similar to CDP, but without paying Cisco license fees :-)
And many more. I know kthat Extreme Networks has their own protocols and I am pretty sure that other vendors have them as well.
The problem with those protocols is when you have a mixed environment. Cisco switches talking CDP do not understand Extremen Network's protocol and vica versa.
If your goal is to find IP addresses to discover, then you might use the ARP caches for routers. Scanning the ARP caches for switches makes no real sense, because they're operating on layer 2.
I was using broadcast message for my java snmp agent

Wifi and LAN at same time

As the question states, I have two ethernet devices I need to use. A wifi hotspot for general traffic as well as a LAN connection for local traffic (192.168.1.*). Right now the wifi receives all traffic and disregards the existence of my local LAN devices. I am trying to communicate with this device using python's urllib2 and basic http fetches. The program works partially when I turn one or the other off (turning wifi off makes the LAN code work, and turning LAN off makes wifi/general traffic code work). I believe this is more of an operating system issue than a programming question, but I might be mistaken. I have been messing with the Ethernet setting in system preferences, but nothing has been working so far.
Thanks for the help.
Depending on your needs and degrees of freedom, you can:
1) Easiest: If you can control one or both network ranges, you can put wifi and LAN on different subnets. For example, 192.168.2.* could be LAN traffic, and 192.168.1.* could be wifi. If only the WiFi side has a gateway, then all traffic except 2.* traffic should route through WiFi, and all 1.* traffic goes to the LAN. No change to your computer.
2) Medium: if you don't control the networks, you can define routing rules for the two ports. This lets you say certain IP addresses should be reached thru wifi, vs others thru LAN port. An example in Linux, which I think should work on OS X too: http://linux-ip.net/html/routing-tables.html The trickiest thing is to make sure you won't get in the way when you're in someone else's network. You can do this by creating narrow routing rules, or turning them off when you don't need them. It sounds like you're doing this from a python program, so maybe the program could turn this on and off at start and finish.
3) Slightly more exotic: I wasn't totally sure from your question, but if you're trying to do load balancing (not separate networks), you could create rules to bond together two network ports and spread traffic across them. This isn't something I've done, but real network engineers know how to set this stuff up.
I could expand on one of these if you clarify what you're trying to do and what degrees of freedom you have.
For somebody don't want to do the study you can simply repeat my steps:
Open system preferences
click on Network
(ensure the precedence, first thunderbolt then wifi) click on thunderbolt
Configure IPv4 choose manually
delete router
done!
I have exactly the same user case. But I read this without any network knowledge.
I achieved this by simply following #Nils' 1) instructions. I only understand theses instructions after reading this link

Redirect Traffic from NIC to Another NIC On Separate Networks While Using Remoting

The project I'm working on is to handle data capture from scan guns (Pocket PC 2003) and process this data on a host (Win XP) then into our inventory database on a separate server (Win 2000). This is all driven by the Remoting framework provided by MS and As Good As It Gets (http://gotcf.net). The application is complete enough for a general proof of concept with both the client and server working properly while in the emulator.
All is well until I began to test using actual scan guns. Due to security concerns, the scanners are on a separate network (for clarification the 10 network) than the server (the 15 network). My development machine has dual NIC connected to both networks and can communicate with both independently. However, I am having issues with my application receiving information from the 10 network using .Net Remoting, and then sending out information to the server on the 15 network via a third party app (Combination of ODBC, Btrieve, and OLE).
Is there anyway to process information from one network then update the server on another?
Any suggestions will be greatly appreciated!
Note: I'm not very familiar with networking, thus I may be calling it the wrong name but the gun IP's start with 10...* and the server IP's start with 15...*
So long as the computer's routing table is properly configured, you shouldn't have to worry about this from your application. So long as you're using the proper IP addresses, the networking stack should take care of delivering things to the right place.
You might want to check the output of "route print" (at least I think that was available on WinXp -- if not, someone else will likely post the correct command for XP soon). In any way, you should see what network destinations are configured for which interfaces. You'll need to make sure that the server's IP on the 15 network will properly route via the interface you want (ie. the lowest-cost matching destination/netmask lists your 15 interface).
The issue seems to stem from both the NIC cards not set up properly and a so far unresolved issue with the frameworks I've chosen.
To solve the NIC problem, the easiest solution I'd found had me clear the default gateway on the 10 network.
The other issue deals with recreating the remoting objects after they've been destroyed. I currently have to warm boot the scanner in order to re-connect to the host. In order to correct this issue I'm going to contact As Good As It Gets to see what their input is. Damn firewall

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