Questions tagged [ethernet]

For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.

18 questions with no upvoted or accepted answers
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IOS XE minimum frame size

I recently encountered an issue upgrading from an IOS device to an IOS XE ASR 1000 router concerning Ethernet Over SONET (EOS). VLAN tags are used to map traffic from the hub router to SONET ...
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4answers
285 views

Access a subnet through another network

We have some devices connected together through a switch. We need to access them through another network, but because of limitations in available IP addresses, we can't get an IP address from that ...
2
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0answers
138 views

Router as PPPOE concentrator, PPPOE clients unable to get to DMZed static NAT server

I've been trying to figure out this problem, and I'm just not up to the task. I have a Cisco 2911 router as follows: Internet connection on GigabitEthernet0/1. Which has it's own static IP: A.B.C.38/...
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0answers
147 views

How an MKA key server decides if it shall use MACSec and how it announce that?

According to IEEE 802.1X-2010 the standard for defining MACSec Key agreement protocol Clause 9.6, that's how the key-server decides to use MACSec or no. Each participant advertises whether it is ...
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0answers
808 views

How are required Keys inside MACSec Key agreement protocol (MKA) generated?

I am trying to wrap my head around MACSec Key agreement protocol (MKA) and its relation with MACSec and other protocols. So bear with me. To my understanding in order to MACSec to work, all nodes ...
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0answers
987 views

Minimum frame size in ethernet CSMA/CD

How long sender needs to transmit to capture the channel in Ethernet when we apply CSMA/CD ? I my book , i have read it sender should be transmitting for at least the 2*PT,where PT is end to end ...
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0answers
47 views

Regarding Physical Connectivity

I have questions regarding the following designs in my test lab: 1.Ethernet port of one switch is connected to TenGig port of the Firewall.Why would anyone do this(connecting Ethernet and Tengigabit ...
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0answers
101 views

How to encapsulate tapped traffic to forward over L2/L3 network?

I am tapping some 10Gb ethernet links at some remote sites (normal passive fibre taps) for some QoS/QoE monitoring. I don't have any dark fibre options at these sites to send the traffic back to a ...
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0answers
242 views

Why does NMAp find disconnected devices?

I want to wake up and see the devices connected on my local network, using NMAP. So I execute this command : sudo nmap -sn -PU[7] -PE 10.11.204.1/24 (extract from the man page : sn: Ping Scan - ...
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0answers
190 views

Is there an acceptable ratio of pause frames?

At the risk of asking an opinion question, are there any guidelines/practices that specify a threshold where the number of pause frames indicates a problem? The ratio of transmitted pause frames to ...
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0answers
91 views

Loop frame case study

Peter Paluch did an experiment regarding loop frame. However I do not understand the connection/cabling on that experiment. Refer statement below. The switch under test was connected via Fa0/1 to a ...
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0answers
14 views

using SNAP/ LLC on ethernet

Why is it not desirable to use Logical Link Control (LLC) and Sub-Network Access Protocol (SNAP) on Ethernet 802.3 frames while carrying IP packets when it is often used for wireless networks?
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14 views

Can the interface types otnOtu, otnOdu and opticalChannel have metrics such as ifInDiscards, ifOutDiscards?

In my understanding, the metrics "ifInDiscards", "ifOutDiscards", "ifOutErrors", "ifInErrors", "ifOutUcastPkts", "ifInUcastPkts".,,,etc are basically related to the interfaceType ethernetCsmacd. Can ...
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2answers
47 views

What is an acceptable bit error ratio?

I recently got a job in IT infrastructure and terminating Cat5e is something relatively new to me. What is an acceptable bit error rate for 1 million packets? Here is a screenshot of a test I ...
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1answer
54 views

Is there any difference between International and United States patch cable?

I'm looking to buy a Cat 8 patch cable. I found a cable that I like that meets ISO/IEC 11801 Class I and Class II but it is not compliant to TIA Cat8 (As defined in ANSI/TIA-568.2-D) which has ...
0
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1answer
58 views

What is the wireless bottleneck speed in my simple network map?

My simple Network topology Im trying to figure out what the maximum speed is in mbps on the blue and red links. The exact specs of the wireless networks are these: IEEE 802.11b/g/n, 2.4GHz Dual ...
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47 views

Why wifi and ethernet use the same frame format from tcpdump -d output?

If I execute tcpdump -i wlan0 tcp -d or tcpdump -i eth0 tcp -d I get the same output (000) ldh [12] (001) jeq #0x86dd jt 2 jf 7 (002) ldb [20] (003) jeq #0x6 ...
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0answers
221 views

How Cisco Line Protocol works

How do Cisco Line Protocol works ? I could read this: https://www.cisco.com/c/en/us/support/docs/content-networking/keepalives/118390-technote-keepalive-00.html, about Ethernet Interfaces keepalive ...