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1500 questions
7
votes
1 answer

MLD messages during IPv6 duplicate address detection

I was wondering if anyone can shed some light on when Multicast Listener Discovery (MLD) messages ought to be send during IPv6 Duplicate Address Detection. RFC4862 section 5.4.2 gives a detailed description of which multicast groups an IPv6 host…
logion
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7
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3 answers

Raman amplifier vs EDFA, what is the tradeoff?

For light amplification for longer-haul fiber lines, as far as I can tell, the two major options are EDFA's and Raman amplifiers. What is the tradeoff between one type and the other? Are there areas where Raman amplifiers are clearly better? Is…
Chris Travers
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CISCO 4500R+E, Sup7L-E redundancy: RPR or SSO?

We are going to deploy 4500R+E chassis with two redundant supervisors Sup7L-E. All ports in chassis - switchport with trunks. L3 interfaces - SVI. Chassis wll terminate L3 domain (route between zone), no dynamic routing protocols, only static…
Эдуард Буремный
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7
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1 answer

Configuring a second MPLS connection for our backup Data center (BGP Closed User Group)

I'm a bit new to BGP and need a little assistance with a configuration change. We are currently using our MPLS connection for all traffic to all sites. Going forward We would want to segragate the Datacenter backup link from the other spoke sites…
mseanmiller
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7
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4 answers

Cisco IOS cli prompts - any way to know which interface you are configuring?

I'm used to the Juniper and Extreme worlds more than Cisco. I'm able to get by OK, but some basic cli issues arise that have finally frustrated me enough. Inside a Cisco ASA 5505/5510 running 8.3+ or a Cisco 2901 router running 15.2. Is there a way…
TheCleaner
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7
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2 answers

DSCP trust boundary

I have performed some analysis and noticed that traffic coming in from the Internet contains a myriad of DSCP values. This traffic competes for voice and video resources on the internal network. How do I establish a trust boundary where all…
Dennis Olvany
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7
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3 answers

How does Ethernet detect a collision in the CSMA/CD method?

I understand that Carrier Sense is essentially the NIC "listening" to the medium for any transmissions, Multiple Access means that multiple devices on the network can "listen" to the medium, and Collision Detection is the procedure it goes through…
user3662222
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3 answers

How do I configure a port as STP "non-edge" on Juniper EX switches?

Juniper EX switches automatically categorize a port as an spanning-tree "edge" (there should only be one device behind the port) or "non-edge" (another switch) port. You can force this mode for a port by configuring set protocols …
Sebastian Wiesinger
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7
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3 answers

How does a network know whether to send via internet/wifi or through cellular service?

I have a decent understanding of networking, but this question popped up in my head randomly and I can't figure it out. For example, if I have an iPhone that is used on a 3G network but is also connected to my home wifi throughout the day, how does…
raisedandglazed
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2 answers

Why are ethernet / mac -addresses in hex and ip numbers in decimals?

Why are ethernet- / mac-addresses in hex (and have 48 bits) and ip numbers in decimals (and have 32 bits)? Does that have historical or practical reasons?
user44840
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7
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1 answer

When is an IPv4 TTL decremented and what is the drop condition?

When an IPv4 packet traverses a router or is processed by a host, the TTL is decremented and if the TTL is too low, the packet is dropped. My questions are: When is the TTL decremented? Before or after the packet is considered for dropping? What is…
joshlf
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7
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6 answers

What is the benefit of a Cisco "top of rack" design?

Aside from the obvious cabling mess you avoid (which I know for us as network engineers is great, but hard to use as an excuse when reasoning with someone who sees no point in it), what do you gain versus copper straight through to a larger…
skrumcd
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7
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1 answer

how to create managment access to SRX Lsys.

is there a way to configure separated admins, one for the SRX root lsys and another to a specific lsys? i'm trying to create two users that when you login with user1 you will login to the root lsys and when you login with user2 you will login to…
Zorik Meyman
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7
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2 answers

Switch security when in an unsecured location

I have a situation where I'm required to install a switch in a location that is physically insecure and has guests coming and going. It is in the audio rack of a sound desk at a facility that has lots of non-staff members that have physical access…
Mark Henderson
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1 answer

Troubleshooting "TCP Zero Window" Issues

I'm currently having a problem troubleshooting a trading application. Let me give a simple diagram of the current network setup (Gov't Stock Exchange Network Router)X-->(256kbs Leased Line)<--X(Telco Router)<-(100mbps fast E link)--->Our Network…
Rufi
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