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1500 questions
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2 answers

What is Dec MOP and how to disable it?

Performing a packet capture I keep seeing strange "DEC MOP Remote Console" frames: No. Time Source Destination Protocol Info 141 83.557841 Cisco_57:62:a0 DEC-MOP-Remote-Console 0x6002 DEC DNA Remote…
petrus
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2 answers

load-balancing difference between DNS and IP - forwarding vs redirecting

I have come across a situation that I cannot understand. We have a Fortigate firewall that we have enabled to do load-balancing across two back-end Apache web servers. A DNS name is then mapped to the virtual IP on the Load Balancer. As expected,…
Yusuf
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1 answer

Label Distribution Protocol(LDP) in MPLS

I have been going through the MPLS technology recently.I have this doubt in my mind after reading some of the features of the MPLS. A---B---c | | D----E Lets say routers A,E are LER and B,C,D are LSR,we want to send traffic from A->E. I…
starkk92
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9
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3 answers

slot vs sub-slot?

I am trying to understand how Cisco interfaces are named, so I am reading the document Interface and Line Numbers in Cisco 1800, 2800 and 3800 Series Routers I am having some issues understanding the principles mainly because I don't understand the…
BrunoMCBraga
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9
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7 answers

What is the purpose of subnetting, if we have NAT?

As I know, NAT is the system, that divides IP addresses into two categories - public and private. Public represents the local network from the outside and private represents the device from the inside. Subnetting divides one IP address into the part…
New Thing
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9
votes
1 answer

ARP request with unicast MAC?

Regarding ARP requests, I got to believe that the destination MAC address was in all situations the broadcast address. Yet I got across this Wireshark capture: I just cannot understand the 3rd request from my router. Why is the destination MAC…
PesaThe
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9
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4 answers

Usage of Flow label in IPv6 header?

I have been reading the IPv6 Flow Label Specification (RFC 6437) and I would like to ask about the purpose of setting this label. In case of just using the 2-tuple (source address, destination address), the packets will reach the destination. And…
Bionix1441
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9
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5 answers

Why is the ICMP protocol considered to run at layer 3 on the Wikipedia page?

Why is the ICMP protocol considered to run at layer 3 on the Wikipedia page (same layer as IP) when the ICMP protocol data is a payload of the IP packet? This is the article on Wikipedia that states that ICMP is in the same layer as IP protocol. I…
yoyo_fun
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9
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1 answer

Is 'switchport protected' supposed to block unicast flooding?

Does having switchport protected configured on an interface prevent unicast flooding for a MAC address the switch hasn't learned? The information that I'm seeing conflicts -- the wikipedia page on unicast flooding cites protected mode as a mechanism…
Shane Madden
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9
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2 answers

Find idle connections in Check Point firewall

I have a firewall, where I have to lower the TCP session timeout from 24h to 1h. Before I do that, I'm trying to determine if this will break any applications, i.e applications that have sessions that can be idle for a long time, but are not able to…
sk0yern
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9
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3 answers

Using latency to calculate OSPF metrics

Is it possible to configure OSPF to use latency in its link cost/metric calculations. The idea being to enable performance based routing whereby the fastest and least congested links in the network will be chosen dynamically, rather than relying on…
PeterD
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9
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1 answer

switchport block multicast vs storm-control multicast

I'm not sure what is the difference in behaviour between switchport block multicast and storm-control multicast and I don't think cisco elaborates the difference very well in their documentation, other than the fact storm-control grants you levels…
CaseyJones
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9
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1 answer

Why does a Cisco AP keep its static IP when erasing NVRAM?

When I erase the nvram on a Cisco AP (1252 and 1262), the static IP assigned to interface BVI1 is not erased. When I do a show startup-config it says there is no startup config. But it always boots with that IP until I manually set it to DHCP…
some_guy_long_gone
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9
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1 answer

Problems Connecting Catalyst 2960G to Netgear Prosafe Via Fibre

I've got a catalyst 2960G, connected to a Netgear Prosafe GS718T switch (cheap manageable switch). Idea is I have a couple of users that need access to a test environment - hence the cheap switch. It's connected via fibre through a 1Gbit SFP over…
user1411
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9
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4 answers

What OSI layer do Access Points operate on?

I am studying for CCNA. In my book I read that wireless access points belong to OSI layer 2. I did some research and I found that is correct. This raised lots of questions in my head so I hope I don't get on your nerves :P I know that these devices…
BrunoMCBraga
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