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2 answers

How ARP works in case of Virtual machine?

As far as my understading goes MAC address is used to recognize a computer node in a LAN where as internet communications happen over IPv4 address. When a request comes from the internet to the gateway the packet has the destination IP address. Now…
Aniket Thakur
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4 answers

Switch Lookup Table

I was just reading a book called HeadFirst Networking and I'm a bit confused about something. I am attaching an image from the book. The page says that the direction of the frames as maintained in the switch lookup table should be a mapping between…
user1369975
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OSPF and routing table

I have several questions on OSPF. 1 OSPF is a link-state prototol, so routers inside an AS only broadcast their link states to all the other routers. I'm wondering if a router doesn't tell other routers its routing table, how can other routers know…
misteryes
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3 answers

why does an interface card in cisco 1921 router not restart after cable disconnect?

I've got a cisco 1921 in a lab setting where we've added an extra interface (EHWIC-1GE-SFP-CU) and as long as a network cable is connected it works fine. However if the network cable is disconnected and then reconnected the inteface doesn't start up…
Johannes Nordh
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What is the correct way to determine SFP+ Direct Attach cable compatibility between switches and NICs?

I'm contemplating a 10 Gigabit link between an Intel x520 NIC and a Cisco SG500X switch. These two would be within 5m of one another, so using one of the Cisco SFP+ passive Direct Attach cables like the SFP-H10GB-CUxM seems an obvious choice. I'm…
alx9r
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6
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How can i add a host to an already existing object group in ASA

How can i add a host to an already existing object group in ASA, without over-writing the already existing members ? Please suggest For Example: Object group TEST has 2 members, and i want to add one more host (192.168.10.10) to TEST, will the…
Rahul
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1 answer

Cisco ASA cannot get "inside" vlan to internet through "outside" vlan

I just got my outside vlan configured up-and-running See Post Here. I was able to get vlan 2 pinging to the internet 8.8.8.8 specifically. However, now I honestly think I am misunderstanding what parameters I should be using ... Here is my config…
Zak
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1 answer

Do we have an SNMP MIB for URIB

As we know that URIB (Unicast RIB) holds various route entries that have been added by routing protocols running on the box (like BGP, EIGRP, etc). Typically, "show ip route" woudl display all entries that are present in the URIB. Does anyone know…
Manoj Pandey
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4 answers

In the TCP/IP model, how does the application layer inform the Internet layer of the destination IP address?

New to networking. How does the application layer inform the Internet layer of the destination IP address? Let's say I make a Http request to www.google.com, which the application layer resolves to 8.8.8.8 via DNS. How does this IP address get…
Kim Akool
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2 answers

What are the different modes in Cisco routers, and why these modes?

I want to know on what basis Cisco designed the different modes in their routers. For example: config mode execution mode Can any one give the perfect reasons behind the different modes? What are the configurations that come under execution and…
user2720323
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Must the checksum field of the IPv4 header always be updated?

When an IPv4 datagram comes to a router for forwarding, does it always update the value of the header checksum field?
dulaj sanjaya
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6
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4 answers

Why can't a single port be used for both incoming and outgoing traffic?

I'm trying to understand something related to network ports, as it's not quite clear to me. The question is, why can't you use the same port number for both incoming and outgoing traffic? This question arose due to some advice on NAT port…
ZenoArrow
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1 answer

CISCO developer routers/ firmware

I was wandering if there are any CISCO routers and firmware for purchase or download for developers so I could test my implementations on them. I am developing a firmware plugin to increase security on dual stack methodologies. Therefore i need a…
Hasitha Shan
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3 answers

Multiple POE over a single cable

I try to solve a problem using Power Over Ethernet technology to Power supply differents devices. I would like to avoid to buy new router and try to make it work without any expensive costs (if possible). Let me explain you the situation : I have a…
Cédric
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1 answer

What does the RTTSum and RTTSum2 represent in a ASA SLA monitor?

I have enabled the SLA monitor on an ASA, and I was wondering what the RTTSum and RTTSum2 Metric Represents? RTT stands for "Rout Trip Time" I am having trouble figuring what the RTTSum actually represent, how would I read it and apply it to…
Blake
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