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1500 questions
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3 answers

Are the IPv6 address space and IPv4 address space completely disjoint?

Tanenbaum's Computer Networks says Finally, IPv4 addresses can be written as a pair of colons and an old dotted decimal number, for example: ::192.31.20.46 Does it mean the IPv4 address space is embedded into the lowest subrange of the IPv6…
Tim
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Why maximum length of IP, TCP, UDP packet is not suit?

From many tutorials, I get follow knowledge(maybe I'm misunderstood) : maximum of an Ethernet packet is about 1500 bytes. maximum of an IP packet is about 65535 bytes. maximum of a UDP packet is 65515 bytes But when I made a test and watch…
Shuai Li
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12
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8 answers

Using sound waves in layer 1

Is it possible, in theory, to use sound waves as the physical medium to transmit data over a network? In other words, could you implement layer 1 of the OSI networking model using sound waves or am I totally misunderstanding the physics/networking…
driangle
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1 answer

What is the "NDE" interface on a Cisco 6500?

I have a pair of Cisco 6509 routers, which are monitored via SNMP (with Observium, to be accurate). Today we spotted a peak of CPU usage for a Switching Processor. The peak can be correlated with a peak of inbound unicast on a port named…
Benjamin A.
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12
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1 answer

Is it possible to connect two private eBGP peers with the same AS number?

The Problem A third party has implemented a small network and private BGP setup within one of our branches. We need to setup a eBGP peer relationship with this network. However we are both using the same private BGP AS number. The Solution One of…
S.Richmond
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12
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1 answer

After TCP is established which BGP peer will send open message first?

After a Tcp connection is established between two bgp peers. which peer will send the open message first ? the active peer(which is initiating outbound connection) or the passive peer?(peer which is accepting a inbound connection). Or is it…
Hemanth
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3 answers

ALU interop GRE tunnel

I've been trying to figure out how to setup a GRE tunnel between an ALU 7750SR and a 3rd party vendor. I think it's balking at the VC-ID in the SDP but i'm hoping someone has experience getting a GRE tunnel to come up in a multi-vendor environment…
Mud
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12
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1 answer

Why can't we find Ethernet checksum in Wireshark?

I am having a small question regarding Ethernet Frame Header Length. As per my knowledge Ethernet Header size is 18 bytes without VLAN tag and 22 bytes if there is a VLAN tag. But in Wireshark capture I am getting only 14 bytes without VLAN tag and…
user2720323
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12
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4 answers

What are the reasons for seeing an incomplete ARP?

As was mentioned in this post: The reason for seeing an incomplete ARP is that "An ARP request was sent for that address, but the host with that address is not up and running on the LAN, so there is no reply" So, if a multilayer switch sends an ARP…
kamokoba
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12
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2 answers

VXLAN vs VLAN over layer 3

I read that one of the benefits of VXLAN over VLAN is that it can spawn across WAN and multiple layer 3 networks by creating overlay layer 2 networks. However AFAIN VLAN can also do the same using MPLS VPN, L2TPv3 or GRE tunnels, or by trunking and…
mart
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12
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1 answer

UDLD in VSS configurations

Since a VSS is a single system image, does it make sense to enable UDLD for links between the switch pair? We've seen some recovery problems that we feel might be due to UDLD mistakenly identifying an ISL link as unidirectional, especially in a…
JPFlathead
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12
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6 answers

Bandwidth vs Throughput vs Data(bit) rate

I totally understand the difference between bandwidth and throughput. While bandwidth shows the maximum amount of data can be transmitted from a sender to a receiver, throughput is the actual amount of data that has been transmitted as they could be…
Nara
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12
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3 answers

How are the hosts in the tracert 216.81.59.173 able to use random domain names?

How are the host names in this trace route able to use random top level domains? I didn't know there was an 'Empire' or 'victory' top level domain. C:\Users\Chloe> tracert 216.81.59.173 Tracing route to read.more.at.beaglenetworks.net…
Chloe
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2 answers

Can I truly multicast over WIFI?

Am streaming UDP over wifi (5ghz) - approx 1.5k/packet... trying to stream to ~10 devices simultaneously, with extremely low latency.. As I understand Wifi, it can never true multicast, as each device holds a '1:1" relationship with the AP, and then…
frank ankersly
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3 answers

Why do we need MAC Address if we can uniquely identify each machine with an IP Address

I learnt that in ARP Protocol, to send a packet from one machine to another machine we need to know the MAC Address of the destination machine but since the destination has already been assigned a unique IP Address then isn't sending MAC Address…
Shivam Aggarwal
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