Questions tagged [networking]
For questions about networking in general. Any question about all on topic network devices can use this tag.
285
questions
0
votes
0answers
8 views
Understanding VLAN 1 and why it is insecure [duplicate]
When reading about VLANS, Cisco mentions that the default Ethernet VLAN is VLAN 1 and it is a security best practice to configure the ports on all switches to be associated with VLANS other than VLAN ...
0
votes
1answer
12 views
Could not access KVM kernel module while building SONiC NOS on vm with vagrant [closed]
I'm trying to build sonic build image for virtual switch from https://github.com/Azure/sonic-buildimage on ubuntu 16.04/xenial vm with vagrant, but I've got an error:
++ on_error
++ echo '=============...
0
votes
1answer
20 views
Network Protocol vs Framework?
I've been a network engineer for almost 4 years now. I thought I understand what a network protocol means. but now I'm having doubts.
For me,
Ethernet is a protocol used at layer 2. there would be ...
0
votes
2answers
31 views
Layer 2 managed switch and layer 3 switch
If you have layer 2 managed switches which have VLAN's on them, do you still need a layer 3 switch/router?
0
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0answers
13 views
Are there any limitations to having a router connected to a router? [closed]
I have router A in a very bad spot so I've been thinking of power-lining one of its LAN ports to another location and connecting another router there.
This second router would have its own clients but ...
-1
votes
0answers
35 views
Hello, Network Problem [closed]
I have a question
I wanted to implement a program in C++, Object Oriented and threaded.
The program must be run in a shell, like the example:
PROGNAME ifs=[IF-LIST]
./desiredprogram ifs=eth01,eth02,...
0
votes
0answers
23 views
How do I setup a datacenter in my home [closed]
So I am buying 50 blade servers tomorrow for $1600 and I plan on setting up a datacenter.
(I have been given the option to colocate or set it up myself so I am not worried)
I have a 1gbps home ...
-1
votes
0answers
11 views
Arduino parses UDP packets through Ethernet with gibberish in it [closed]
Arduino Yun (with built-in Ethernet) is connected to a PC (through Ethernet) which is connected (through WiFi) to my router.
Is set to receive UDP packets from another PC (on the same network).
That ...
0
votes
2answers
20 views
why sometimes we need to use Broadband Transmission (Using Modulation)?
I was reading a textbook which says:
Baseband transmission requires that we have a low-pass channel, a channel with a bandwidth that starts from zero. This is the case if we have a dedicated medium(...
0
votes
1answer
21 views
How to identify Digi CM Console Server via command line/SSH?
Digi CM Console Server is a Secure Access and Management for Servers and Network Devices
https://www.digi.com/products/networking/infrastructure-management/console-servers/digicm#overview
How do we ...
0
votes
3answers
37 views
Can the network devices run out of ephemeral ports due to high use of websockets?
This might be a really stupid question, but something I really want to understand.
My understanding is a tcp connections staying open indicates that each of the network devices between the client and ...
0
votes
1answer
24 views
iperf3 UDP tuning
I am trying to test throughput in the network. But when i start iperf3 client for sending UDP packets it sends TCP SYN packets. Why does it behave like this? (it should not send udp tcp syn while ...
2
votes
6answers
2k views
Why can't we create a hierarchy of hubs?
I was reading the Comptia Network+ All in One book and I came to know that we cannot create a hierarchy of hubs. My question is why so? Are MDIX ports simplex? Why is it not possible for the hubs to ...
0
votes
0answers
7 views
Azure Private Link [closed]
In Azure Private Link, how is it possible to have for example a SQL server which does not have an internet gateway, NAT devices or a public IP address but still being able to connect externally ...
0
votes
1answer
25 views
Unicast and Multicast MAC address convention
I need help in understanding how Unicast and Multicast MAC address is differentiated as explained in wiki.
According to what I understood, when the least significant bit is set as 0 in the first octet ...
0
votes
1answer
18 views
Does Telnet need to be activated on both devices I am using or not? [closed]
I've searched everywhere for the answer to this question but can't find a simple yes or no.
Basically, I have a virtual server hosting some services and then a physical panel PC in another part of the ...
0
votes
1answer
33 views
Routers and layer 3 switches for connecting two buildings on site using fiber
I understand layer 3 switches are essentially routers, but often don't have the capabilities a router has, e.g. NAT. So I'm trying to work out where it would be necessary to have layer 3 switches vs ...
0
votes
1answer
53 views
Is it possible to setup IPsec behind NAT without port forwarding?
We want to setup a IPsec connection between customer sites and our office so we can manage the hardware we place at customer sites (e.g. barriers). Its important that the VPN connection stays up all ...
0
votes
3answers
59 views
Assigning IP addresses to multiple switches
Thank you in advance for taking the time to read my question, i appreciate it. I am in need of help on IP assigning to 4 brand NEW Araknis switches that I am replacing with the current netgear/tp-link ...
1
vote
1answer
63 views
Do mobile phones continuously broadcast their IMEI number so that cell towers can find them?
Edward Snowden said that in an interview. Is it exactly true? Does it have to do with SSN (sim serial number)?
Is the SSN broadcasted with encryption and modulation done to it or is the IMEI number?
1
vote
0answers
5 views
5g authentication method for IoT [closed]
While i was studying authentication methods in 5g i bumped into 3 authentication methods that seems to be the most important ones: 5G-AKA,EAP-AKA,EAP-TLS.
Which one of these three could be more ...
0
votes
1answer
36 views
TCP Handshaking Meaning of RST
I am trying to implement TCP handshaking but receive RST instead of ACK:
No. Time Source Destination Protocol Length Info
62 24.622012890 192.168.0.147 ...
0
votes
3answers
47 views
Why is the trace route to a particular IP not the same as trace route from that IP to mine?
So i am running a trace route from http://www.speedtest.com.sg/tr.php to my system. i get a route. And i run a trace route from my system to the website above i get a different route. Why is that? Why ...
0
votes
2answers
42 views
Reconciling multiple definitions of Bandwidth
I am confused about the meaning of the term 'Bandwidth' in a wireless transmission environment. The two most common definitions I could find are:
difference between the upper and lower frequencies in ...
0
votes
2answers
38 views
Modify the IP in TCP/IP packet
My ip address is specified in the ip packet sent to the next node. I wonder if a device that handles this packet can modify the ip address before forwarding it to the final destination?
In theory ...
0
votes
0answers
13 views
CCNA static IPv6 interface id understanding question [duplicate]
Hello,
Can anyone advise why I would add ::1 to a subnet in IPv6? In this case I am looking to use the global unicast address and not the link-local even though I would normally do this.I would add ...
1
vote
1answer
43 views
Can people with an ISP access your network if it is on the Default Free Zone?
Let's say you have a router on the DFZ (despite costing an absurd ammount of money). Would your network work the same as if you have an ISP in terms of web hosting, etc?
Can people still access your ...
0
votes
1answer
16 views
Whether PPTP Client need virtual interface to communicate with PPTP Server? [closed]
We know in PPTP VPN, the VPN Server is using a virtual Interface to provide encrypted data.
Whether PPTP Client need virtual interface to communicate with PPTP Server?
and more, if yes, whether ...
0
votes
1answer
28 views
filling routing table with next hop addresses
in a multi hop network when the packet leaves the source is it loaded with all the ips of the stops on its journey, then at each hop it checks the bitmask with the nodes routing table to see if this ...
0
votes
1answer
16 views
Some questions about a DMZ and where to place my web servers? [duplicate]
Currently i build a new network for our company which is not my specialism as i'm actually a software engineer so excuse me when this is a stupid question.
I read a lot about networking last few ...
1
vote
2answers
64 views
Vlan vs. Subnet Broadcast Domain
It is my understanding that Vlans separate broadcast domains, but I often see people say, "subnets define a broadcast domain" as well.
Is it correct to say, "Vlans define a L2 broadcast domain, and ...
0
votes
4answers
83 views
Firewall placement
Ok, so I'm confused on the placement of firewalls, most diagrams I come across are as follows:
ISP > router > firewall
However, I'm confused about this, surely you would want a firewall before the ...
0
votes
2answers
44 views
Best way to make a network failsafe?
I have a Debian based machine with 2 completely different network interfaces from 2 different ISPs acting as a backup for my server connection. These have two different IPs (Let's say IP1 and ...
0
votes
1answer
23 views
Understanding IP scheme, distribution and usage [duplicate]
I'm new to networking and I'm doing my best to understand how things work. I do have a problem in understanding IP scheme idea (even though obsolete), more specifically, their structure, distribution ...
1
vote
0answers
80 views
Why can't i reach devices in the other network?
I have 2 networks and want to connect them with each other. It should be possible that all devices in network A can communicate with devices on network B and other way round. 1 network is "managed" by ...
0
votes
1answer
21 views
Additional subnets in a class C IP [duplicate]
If i'm designing a new subnet mask for a class C IP that will have 5 subnets that means I need to borrow 3 digits since 2^3-2 > 5. My question is, how many additional subnets do we have?
would it be ...
0
votes
2answers
28 views
Will TCP packets smaller than the full bandwidth of its link travel at the same speed?
If I send 5bytes over a 1mbps connection will that travel faster than 500bytes. Or is the latency after propagation going to be constant since the packet is under 1mb?
If you downvote because you ...
0
votes
2answers
62 views
Why cant i reach the other network while i have added the routes and firewall rules to allow traffic? (Pfsense/USG200)
I have 2 networks, the current one and the new one. The current one is not configured by me and one big mess and contains heavily out dated hardware (especially servers). I want to be able to access ...
0
votes
3answers
48 views
Are there any alternative devices to routers?
I am not talking about the router used at home to access Internet .
I am talking about devices used in the network core.
I want to know if there are alternative devices, if any, used for forwarding ...
6
votes
2answers
1k views
Encapsulation: can a higher protocol encapsulate a lower protocol?
I've heard someone say that a protocol higher up the osi model can encapsulate a lower protocol.
As far as I know, personally, a protocol can only encapsulate a same-level protocol or one at a ...
0
votes
2answers
31 views
Who owns the in between routers displayed when I execute a traceroute command?
When i traceroute a website, i get the IPs of all the routers in the path between me and the website. Who owns all those routers? Are they organized in a particular kind of building?
0
votes
2answers
38 views
Fat-Tree topology
Fat tree network topology looks like a tree topology like below figure. In tree topology, we have same terminologies like Root, parent, child etc. This is mainly used to connect a large number of ...
1
vote
0answers
15 views
How many times is the data packet copied before finally reaching the NIC? [closed]
On a typical linux machine, how many times would packets be copied from the application layer to all the way in its journey to the network card. I am assuming the protocol being used here is TCP/IP ...
1
vote
2answers
67 views
Which is the best way to encrypt all the IP traffic in LAN?
I'm trying to encrypt all the IP traffic in a small LAN network but the in that network all kind of devices are connected i.e. PCs, Laptops, IP Cameras, IP Sensors, etc (new and old devices).
I have ...
0
votes
1answer
62 views
What steps must be accomplished in each layer of the TCP/IP model to connect a website?
What steps must be accomplished in each layer of the TCP/IP model to connect a website?
0
votes
0answers
6 views
Why does the sender assume that packet n is lost if it receives 3 back to back ACKs of packet n-1? [duplicate]
I came across an unjustified statement in my study notes regarding TCP:
If sender receives 3 duplicate ACKS back-to-back, it
assumes that the next packet in sequence was lost,
and re-transmits. ...
0
votes
1answer
40 views
why the size of a frame is dependent on the data that is being sent in the payload of the frame
I'm new to networking, just a question on frame size. I was reading a book which says:
An interesting characteristic of character/byte stuffing, is that the size of a frame is dependent on the data ...
0
votes
1answer
46 views
Create IPSEC VPN between three Routers?
I'm attempt to build essentially an IPSEC tunnel mesh between three Cisco IOSv routers. I've been able to build an IPSEC tunnel between two directly connected routers but once I add the third router ...
0
votes
1answer
26 views
Getting network traffic of a remote IP? [closed]
(Not sure if this is the right place to ask)
I want to get the network traffic and packets of an IP outside of my network from IP. For example, I can sniff my own network using Wireshark. Just like ...
0
votes
2answers
35 views
Fiber dBm transceiver power level at warning
We have cisco nexus 9000 and one of 40G interface showing port transceiver power level at warning when i check on command line i found following.
Question:
what is the normal power level for ...
