Questions tagged [packet-path]
Use this tag for questions about the life of a packet *within a switch, router, or firewall chassis*. Do not use this tag for questions about traceroute, or traffic engineering.
44
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Why is MPLS label added between layer 2 header and layer 3 header of OSI model and not between headers of layer 3 and 4 of OSI model?
Is there a possibility to use any other two OSI model layers' middle positions? What is the basic concept of switching of packets with MPLS on layer 2.5 of OSI Reference model?
2
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0
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How lsp-ping works with php in picture?
If my understanding is correct, lsp-ping will have destination IP addresses set to loopback address(127.0.0.x), to force the label switching of the packet and thus checking the LSP connectivity.
When ...
- 1,124
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2
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Mobile cellular Networks (GSM, LTE, 5G, ...) and MAC addresses
We've been provided with a new firmware for our telematics units, which connects to the Internet via a VPN provided by a mobile carrier; since this new firmware release, we've noticed that each and ...
- 133
0
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1
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Total delay of virtual circuit switching? [closed]
We know that virtual circuit switching(VCS) has both features of circuit switching and datagram switching. It uses connection oriented path but may or may not dedicated that means resources may or may ...
- 378
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2
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332
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pathping command 100% packet loss
this is the real example of pathping command.
According to my knowledge:-
Source to here column :- it tells about number of packet loss out of 100 send directly to hop
Node/Link column. :- it tells ...
- 31
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2
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374
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Message switching vs packet switching with respect to congestion traffic
Packet switching uses store and forward technique to forward packet. And message switching is also uses store and forward technique to forward message. But in packet switching data transfer faces ...
- 378
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0
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ISDN, DSL, Circuit Switching and Package Switching [duplicate]
I need a bit of help to clarify the above-mentioned terms. From my reading, I can see that both ISDN and DSL are used over telephone copper lines. However, ISDN is associated with circuit switching ...
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1
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23
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IP router not forward the packets it receives [closed]
I have been searching for a answer to this and have not found a definite conclusion. Everything seems to suggest
In what cases may an IP router not forward the packets it receives?
My guess which ...
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2
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1
answer
544
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Transmission and propagation delays
I am now working through book "Computer Networking - A Top Down Approach", and there is one question among others after the first chapter:
"Consider two hosts, A and B, connected by a ...
- 23
0
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1
answer
77
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Do using proxies and surfing the internet create multiple headers in the packet? [closed]
Apologies for these silly questions. As I am new to networking.
For example, If I configured my browser to use proxy of IP address: a.b.c.d and my IP address: e.f.g.h.
And I visit example.com. What ...
- 3
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2
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114
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How BGP guarantees same route for a forwarded packet?
In BGP all routers choose the best route to a single destination. So for Router A and destination D, A will forward the packet to the next-hop router (let us say router R) after knowing the best route ...
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2
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2
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Is datagram switching only possible with routers?
So datagram switching is when packets from same original message travel different paths from source to destination. This cannot happen with switches because switches would just run STP thus ...
- 471
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2
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How is Ethernet a packet-switched network?
Let's say for example there is an Ethernet switch, and there are four PCs connected to this switch. PC1 and PC2 are communicating with each other, and at the same time PC3 and PC4 are also ...
- 471
2
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1
answer
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Is a new Frame created between Routers and also Hosts
Trying to understand how frames are structured between hosts and routers. My basic understanding is that a new frame is required to encapsulate a packet from each router.
Example being, if you have ...
0
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1
answer
99
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How does packet traversal works over a public network with NAT overloading
Let's say I have a private network connected to the internet with default gateway 192.168.1.1 on Router1. Now a host(Host#1, 192.168.1.10) on this network wants to send a packet over the public ...
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1
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3
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How do routers intercept packets?
I'm trying to learn about iptables and port forwarding and I'm running into a very simple hurdle. If my understanding is correct, this concept applies when there is a local area network, a router, and ...
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5
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Does a Layer 3 switch become a Layer 4 device when telnetting?
In order to Telnet to a switch (Layer 2) we create an SVI, thus a layer 3 point of contact is made. The switch inspects each packet sent from the remote client and responds to it so that it gets ...
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1
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Is it possible to append custom data to every packet of a request? [closed]
For an end-to-site VPN, i.e. where a device (VPN client) is responsible for encapsulating the GRE packet, is it possible to send some custom data along with the GRE packet beyond just the standard ...
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3
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How do VPN's forward network traffic? (Layer 3)
I am looking for some info on how VPN's (Virtual Private Network) forward network traffic through its VPS (Virtual Private Server).
Take an example where you are connected to a VPN. You make a ...
- 205
0
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1
answer
371
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Do packets travel through household routers or only designated ones? [duplicate]
I'm trying to wrap my head around the path the packets take on the internet.
I know that they hop between multiple routers until they get to their destination, but are these routers only in ISP's ...
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0
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1
answer
308
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NS2 program specifications questions
I am using the Network Simulator NS2 program (https://www.isi.edu/nsnam/ns/) in order to simulate a simple network topology with 1 UDP agent and 1 CBR Application Traffic sending data from a node over ...
user30757
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2
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What could cause network to duplicate packets? STP during convergence?
I have understood that real networks have routing changes, leading to out-of-order delivered IP packets. Real networks also have frequent packet loss.
However, what I have not understood is why could ...
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2
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2
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Store-and-forward packet switching delays
My question arose as i was reading Computer Networking a Top Down Approach . The author said the following regarding packet switching:
L = length of packet(bits)
R = transmission rate(bits/sec)
"...
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1
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1
answer
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Packet forwarding in Circuit switching
Does circuit switching make sure that all packets follow the same route?I understand that there will be a dedicated path between two end systems before data transfer and all packets are received in ...
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2
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235
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Network redundancy with low cost switches in a ring
I'm designing a network which is physically arranged like:
|---------------------------[router]---------------------------|
| |
|--[s]--[s]...
- 115
1
vote
1
answer
625
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BGP local preference
While configuring BGP on Cisco IOS, the
sh ip bgp
command lists the local preference of each of the learnt routes. I understand the default is 100. However for some routes, it is explicitly ...
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1
vote
1
answer
102
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If multiple PC's are communicating to a server via a router, is the individual PC network traffic isolated to the respective PC's network?
I currently have multiple servers which are all on their own separate networks (each server on a different network talking to other devices). I want to implement a common central data server which ...
1
vote
2
answers
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Is an Ethernet Packet sent to all the hosts on a network?
Is an Ethernet Packet sent to all the hosts on a network, and then all of them discard the packet except the right host to which the packet was sent to?
This page here says:
Local networks like an ...
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2
votes
2
answers
148
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Why do the same websites get routed in two widely different paths?
Depending on the time, when I open a website and do a traceroute, I notice that website goes to a different path than the usual, and some websites just never open. Why the same network alternate ...
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3
votes
1
answer
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Data Flow between VLANS
I have a setup like this. (Yes, I suck at Paint)
What I know is:
1) Only the ASA knows sees PCA AND PCB. Because the ASA is the only one who is connected to both VLANS. Am I right?
If I want to ...
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0
votes
1
answer
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Flow Definition
I want to ask a definition question. What is "a network flow whose packets are sent on a single path" called? Is it unsplittable flow, integral flow, or integer flow? or something else?
Thank you in ...
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2
answers
376
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Matching a packet in OVS
I'm new to OVS and I'm working on an OVS project, and i read a lot of documents about it but i didn't find anything that can make things clear to me about matching a packet and in userspace and ...
3
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1
answer
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Manual setting MTU still needed today?
Symptom
ssh to remote-host works.
Simple output like ls works.
But more output like find / fails.
Solution
In our case we reduced the MTU to 1200 on eth0 (IPv4) and the symptoms disappeared.
...
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vote
1
answer
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MTU when creating IPSec Packets
I'm trying to understand the MTU management when creating IPSec packets.
If a IP packets already has the MTU, the resulting IPSec packet will be too large for the outbound link.
Is there a IPSec ...
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2
votes
1
answer
994
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How does TTL of package changes?
Consider a following scheme:
Server(TTL=64) <--> RouterA(TTL=64) <--> RouterB(TTL=64) <--> Desktop(TTL=128)
The Desktop sends a package to the Server, this package on the netowrk ...
- 123
0
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2
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I'm confused about ethernet interfaces (eth/in, eth/out, eth/local)
I'm using an Edgemax router (EdgeOs), and even after having read posts and checked internet pages, I'm still very confused about which of my ethernet interfaces are communicating with what.
My LAN is ...
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0
answers
830
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BGP transitive attributes for single ASN multiple prefixes multiple neighbors
I believe I'm on the right track, but have stumble across something with advertising BGP prefixes to neighbors. I am wonder how if I have a single ASN with multiple prefixes (99.1.1.0/24 and 111.1.1.0/...
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2
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What to do when there is high jitter in tier one connection(s) [closed]
I have a couple of dedicated servers in Europe. Lately I started to notice high jitter for traffic coming from USA.
After couple of MTRs and trace routes, I found that the source of the jitter (and ...
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1
vote
1
answer
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Does RSP forward ICMP ping to IP of its interface to CPU on control plane or not?
For router with route switch processor (RSP), if an IP address is configured for the RSP interface and the IP is pinged, is the ping forwarded to the main CPU (control plane)? Or the CPU of RSP will ...
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5
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Why don't switches always flood?
If a switch doesn't have a destination in its table it floods to all (but the sending) ports. Why doesn't it always do this if it can, since it would be faster than doing a look up in a table? I guess ...
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2
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1
answer
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How source node knows the destination node address beforehand?
This might be a duplicate but I didn't find it.Maybe I didn't used the right keywords while searching.
I was reading this book and in Chapter 1, it was written that
When a source node wants the ...
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0
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How do Wi-Fi access points discard frames on adjacent channels?
Naturally, Wi-Fi devices (access points, client adapters) receive frames that were sent on an adjacent channel as these overlap, i.e., they 'see' frames that were sent on a channel that the device ...
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2
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What does getting packet in and out of CPU means from a switch standpoint
I am using a managed switch (e.g. 12 port) which consists of a switch engine + MIPS CPU all on one single chip. I came across a sentence while reading the switch documentation which said to get ...
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What path does a packet follow through a Cisco Nexus 5k/2k infrastructure?
I was told by someone that a packet going between two hosts connected to the same Nexus 2k would end up being passed all the way up to the 5k that is managing said 2k for logic to be applied and then ...
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