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1500 questions
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3 answers

Find MAC address of a remote computer using IP

Is there a way to find out a computer's MAC address if we know its IP address, assuming this computer is outside our LAN? I know we can easily get the physical address of a computer in our LAN using getmac or arp in command prompt, but these…
a_kris
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enforcing QoS on a "variable" speed link where the negotiation is done by the carriers NTE

In essence we purchase a 80/20 line from the carrier who provides the transport between the customer premises & the local exchange where the carrier terminates into our PE. (Juniper PE) <--> [Carrier interconnect in Exchange <---> NTE in customer…
DrBru
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3 answers

What is a "Layer 3 Switch"?

What is a "Layer 3 Switch"? I essentially understand the OSI model, well maybe I don't and maybe that is why I don't understand. Its just that I don't see how/when/if a "managed switch" becomes a "layer 3 switch". Or, is a "managed switch"…
Mark Christopher
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1 answer

How do you get rid of deleted sub-interfaces from NVRAM?

This is more of a cosmetic issue however it does bug me.... I removed the sub-interfaces off a 3845 router by issuing. no int fast1/0.10 no int fast1/0.15 default int fast1/0 When I do a show run....the subinterfaces are no longer there. However, a…
knotseh
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11
votes
4 answers

Using IP addresses from IP pool given by ISP

My ISP says that it can provide an optic fiber connection with a pool of 4 static IP addresses (subnet 255.255.255.248 i think). My question is that if I get that connection, 1 ip will be used for network 1 for default gateway 1 for broadcast. So I…
Gaurav Sharma
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11
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3 answers

Two Cisco ASA 5525-X as Internet Gateways without Layer 2

Add another reason to hate NAT to the list. I'm bringing up two Internet egress points in our corporate network. The edge devices will be ASA 5525-X firewalls. Traditionally you would put these into some sort of cluster, but this requires L2…
bigmstone
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3 answers

Do today's routers prevent fake IP headers?

I know people can modify the IP headers and change source IP address, but it should be simple for network devices to detect those messages. If they don't, why is it so hard? Does it add too much overhead?
Nachos
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3 answers

Does Cisco 6500 VSS improve or hurt MTBF?

I understand the benefits of the Cisco 6500 VSS with the obvious selling points of single management, single routing instance, STP elimination, port-channels across chassis, etc. With two standalone Cisco 6500s that may have L3 and L2 port-channels…
generalnetworkerror
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3 answers

Whats's the function of a loopback interface in routing protocols?

So I've got this task where I have to setup a virtual network with an OSPF routing protocol. I firstly ignored this loopback interface I had to configure on the routers since it didn't do any difference in this virtualization software called Cisco…
iPh1ps99
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11
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6 answers

When does switch talk to router

I have read a lot on how switches forward within LAN, but little about how switch talks to router. When does a switch send packet to router ? Is it when it does not find recipient on the same LAN ?
JavaDeveloper
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11
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2 answers

Extend MACSec encryption over provider bridge

I already asked this question on SF, but figured it might be a better fit here. Is it at all possible to extend MACSec encryption over a provider bridge? Will the typical 802.1ad implementation be able to forward the encrypted frame, or will…
Roy
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11
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3 answers

What is the proper way to config a Site to Site IPSEC VPN and a Remote Access VLAN on the same external interface? Cisco 891 ISR

I'd be happy to post the config or logs for reference but I am having trouble getting my remote access VPN working on the same interface as my site to site IPSEC VPN. I am using a dynamic crypto map for the remote access vpn but it looks like it is…
Bill Gurling
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11
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1 answer

WLC - How to disable 2.4Ghz

Is there any way I can disable the 2.4Ghz and just leave 5.0Ghz channel enabled on a per WLAN (SSID) basis? Or the only way is to disable the AP's radio and leave 5Ghz enabled?
Brown Taylor
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11
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3 answers

What are the alternatives to OTV for stretching a layer 2 network across 2 datacenters?

We want to find a "safe" way to stretch layer 2 network across 2 data-centers, and since we don't have any equipment running NX-OS on either data-centers we can't use OTV. So what are the alternatives for us who have the following equipment at…
mastrboy
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11
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2 answers

Handling VLAN based MPLS circuits with site specific internet access

I'm having difficulty wrapping my head around how to set this up and the MPLS vendor is being no help so I figured I would ask here. I have a 2 node MPLS each site having internet access on the same circuit the MPLS rides in on. These circuits…
TheMoo
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