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13 votes
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What do packets look like?

To transmit data you need a media (copper or optical fiber, for example) and each media has its own set of features than make it usable for data transmission. For example copper is a good electrical ...
jcbermu's user avatar
  • 4,497
7 votes
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F5 as a backbone router

Pushing full routes into a load balancer is about as far from best practice as you can get. Give it a default route to an actual router and a static route back to your subnets and it should be able ...
rnxrx's user avatar
  • 6,124
7 votes

What are the significance of different types of routers?

These are not different types of routers, they are different roles. It usually depends on where, topologically, the device placed in the network. Edge routers, for example, are placed at the network ...
Ron Trunk's user avatar
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6 votes

Cant ping & access HP switch on network connected on trunking mode

(Disclaimer: I am not familiar with HP switches, so I wont' be able to give proper command syntax for show/display commands). For a first, let's leave all routing discussion aside. AS5500 an AS3100 ...
Marc 'netztier' Luethi's user avatar
6 votes
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Should a Metropolitan Area Network (MAN) be setup with a router at each site?

Yes. You do not want to extend Layer 2 MAN links beyond the border of each location - this is bad design for a number of reasons: You will extend the broadcast domain of all 5 sites up to the main ...
Benjamin Dale's user avatar
5 votes
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Access-list is it the same command of Access-group?

Proceeding from the assumption that you are talking about Cisco gear, it is basically as you said, they complete each other. Neither an access-list nor an access-group on its own will have any effect. ...
Daniel's user avatar
  • 1,071
5 votes

WSN vs Ad hoc in real practice

Just so we're clear on terminology, in the 802.11 spec, Ad-Hoc is a mode of operation of the wireless client interface - this allows direct connectivity between two (or more) wireless stations that ...
Benjamin Dale's user avatar
5 votes

What is a headend device?

It's the last point of significance in a service provider's network, relative to the consumers of that service, from the point of view of the service provider. For example, in the days of dial up ...
AlwaysLearning's user avatar
5 votes
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The Difference between session and flow in networks

A flow is the data-plane stream of packets between sender and receiver that shares key IP header information. For example, a client at 10.1.1.1 port 12398 communicating with a server at 192.168.1.1 ...
cmschmidt15's user avatar
5 votes
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How to use MCLAG for In Service Software Upgrade (ISSU)

I think he's referring to "zero downtime" if you're connected to multiple switches. If you're only connected to Switch A, and I reload that switch for a software update, you're obviously going to lose ...
Ricky's user avatar
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5 votes
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Are there any alternative devices to routers?

If you need to forward between different L2 segments/L3 subnets then any device actually doing that is a router by definition. So, there's no alternative to a router (which may be a classic router, ...
Zac67's user avatar
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4 votes
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BGP Question please

BGP does not care if the peer is directly attached or not, as long as peers can communicate with each other, so from BGP point-of-view both topologies are strictly identical. This is why there's an ...
JFL's user avatar
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4 votes
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TCP Client-Server with mtu is set, Issue with fragmented packets

You are confusing MTU and MSS. The MTU 1500 is related to ethernet, so it includes the IP and TCP headers. Both have a minimum size of 20, so the MSS (maximum segment size) for TCP is in this case ...
JFL's user avatar
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4 votes

Subnet and routing on IPv6

Routing works the same in IPv6 as IPv4, so yes, a /128 address can be routed. However, you should not create subnets with prefixes longer than /64**. RFC 7421 explains why. ** The exception is point ...
Ron Trunk's user avatar
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4 votes
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Cant ping & access HP switch on network connected on trunking mode

You should check the portal server limitations, since it is enabled on A5500 Vlan 1 interface: # interface Vlan-interface1 ip address 172.16.1.1 255.255.255.0 portal server 1 method layer3 # While ...
Marco De Lellis's user avatar
4 votes
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Cisco 3064 switch upgrade from 6.0.x to 7.0.x issue

Soution: For testing i have download 7.0(3)I4(4) nx-os file but same issue, no luck :( But then i decided just Install instead of verification and it works! switch# install all nxos bootflash:nxos....
Satish's user avatar
  • 4,379
4 votes

Given a network switch, can we identify the devices (IP not assigned yet) connected to it?

If you can get the server to generate some traffic, you can determine the manufacturer of the NIC card from the OUI portion of the MAC address. That isn't the same as the server manufacturer, but ...
Ron Trunk's user avatar
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4 votes

Unbundling local loop

The term "local loop" comes from analog telephony. It is also called the "last mile." The definition is not precise, and certainly things like "access medium" were never imagined when the term was ...
Ron Trunk's user avatar
  • 67.7k
4 votes

Deploying Virtual Stackwise Catalyst 9400

According to the documentation for Configuring Cisco StackWise Virtual The SVL link needs to be connected to the sup-module. StackWise Virtual Link (SVL) connections are established only through 10G ...
Roger Sanghee Gold's user avatar
4 votes

Symmetric routing and asymmetric routing plz elaborate

Symmetric routing - packet takes one path towards for example google server and turn back on using the same path. Asymmetric - packet takes one path towards for example google server and return back ...
kubn2's user avatar
  • 463
3 votes

Gateway changing source MAC address in packet headers

An easy explanation would be like "IP Address is End - to - End. Mac Address is Hop - to - Hop." Your layer 2 details are valid and useful only in your network, so the gateway changes the mac ...
Joel Thomas's user avatar
3 votes
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Duration of TCP connection last in idle state(no data exchange)?

Considering you are not sending any traffic, connection quality has no impact here, because TCP connection on your end-host will not terminate even if you cut the cable between the end-hosts, as long ...
NetworkMeister's user avatar
3 votes

Network distribution/core design implementation

The 3650 will switch layer-2 at wire speed, even if you have it fully populated. You cannot get more traffic into the switch than it has ports. When it comes to routing, there are too many variables ...
Ron Maupin's user avatar
  • 99.9k
3 votes

BGP Question please

If you can directly attach 2 hosts, do it. If the link goes down, all your routing protocol will react instantly. Otherwise you will rely on routing protocols timeouts. Moreover a more densely ...
Xavier Nicollet's user avatar
3 votes

iBGP vs eBGP peering with ISP

You will likely run eBGP, since your AS number and the ISPs AS number are different. If you do not have an AS number, you can use one of the private AS numbers (analogous to private IP addresses). ...
Ron Trunk's user avatar
  • 67.7k
3 votes
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Cisco restrict MTU size

You can do this with policy based routing, although this is an example of filtering any packet bigger than 512 bytes, it does not make your router fragment packets to 512 bytes. ip access-list ...
Szombatfalvi Hunor Gellèrt's user avatar
3 votes

Subnet and routing on IPv6

A IPv6 /128 is a host route, exactly like a IPv4 /32. A /127 is a point-to-point route, exactly like a /31. In the IP allocation database we'd usually allocate a /127 as the only network in an ...
vk5tu's user avatar
  • 1,171
3 votes

Change MTU without infrastructure change

You haven't described the network very well, but if your switches are not set to use jumbo frames, any jumbo frames reaching a switch will be dropped as a giant. Jumbo frames are not really ...
Ron Maupin's user avatar
  • 99.9k
3 votes

Cisco 3750 switch to Cisco 1841 router to Cable Modem?

You forgot the command ip nat outside On the external interface Fa 0/0
Ron Trunk's user avatar
  • 67.7k
3 votes
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Cisco 3750 switch to Cisco 1841 router to Cable Modem?

In addition to the missing ip nat outside command suggested by Ron Trunk, you are only allowing NAT Overload on VLAN 100. If you want to allow NAT Overload and allow Internet access on VLAN 200 and ...
TDurden's user avatar
  • 1,241

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