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1500 questions
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2 answers

What considerations should be made when determining whether to use the BGP "network" command vs Redistribution?

BGP has three ways to advertise a route: network command redistribute command Aggregation There are two reasons I've come across for using the network command vs the redistribute command: 1. The network command advertises routes with an origin…
Eddie
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Devices that utilizes CISCO IOS Operating system

I am a bit confused about the CISCO IOS operating system. My final year research project is based on solving some security vulnerabilities that i dug up that exists in the CISCO IOS, thus i need to find a CISCO router to implement my solution. This…
Hasitha Shan
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5 answers

Different subnets in the same LAN

I have a very rudimentary doubt. We know that a LAN has addresses in the same subnet. The LAN ends at the gateway router with that interface also belonging to the same subnet. But what exactly will break in the forwarding operation if we assign LAN…
john
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1 answer

Cisco CatOS - show port usage output

I'm in the process of replacing some switch blades and i'm looking through the show port usage command on the older catos switches. I'm struggling to understand the output for the show port usage command (enable) show port usage 6/47 Port Status …
Oli
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6
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1 answer

Zyxel USG100. GS1910 Vlans cannot access wan

Iam trying to configure a network that looks like this: My Vlans and static routing seams to work fine, i am able to ping between the VLANs. My problem is, when i try to make a connection to the internet, I get a time out when trying to ping, i am…
Rune Jensen
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6
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1 answer

Filter ARP packets with specific "Who has" and "Tell" IP

Here is an ARP packet: 192.168.1.3 ARP 62 Who has 192.168.1.1? Tell 192.168.1.2 How to display only ARP packets with 1) specific "Who has" IP (192.168.1.1 here)? 2) specific "Tell" IP (192.168.1.2 here)?
user207114
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1 answer

What should a device do with an Ethernet frame larger than its MTU?

When I test with Cisco 2960 series switches or with ISR routers, then if port receives an Ethernet frame larger than its MTU value seen in sh int output, then device drops this frame and increases the giants counter. In my opinion this is an…
Martin
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HSRP and Static NAT behavior

May I have your opinion on the following matter? Configuration: Two 2911 routers. Doing HSRP on Wan and LAN side with 2 standby groups. Doing static NAT to internal servers. Added redundacy keyword on the nat statements . Tracking wan side interface…
Tsubasa
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5 answers

Do we really need ARP when only hubs are used to connect devices?

In the case only hubs are used to connect devices do we need ARP? Packets will be forwarded to every device. So, when a packet whose destination IP doest does not match with the device IP, it will be discarded. In such a scenario I believe that it…
gaetano
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1 answer

SRX100 in bootloop. Flash storage problem?

About a month ago one of my SRX100 started to go into a bootloop for no obvious reason to me. After some hours, it eventually stopped and booted up the system again (primary) and I was happy that I could create a rescue config. However, I did not…
xeet
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2 answers

Should I disable STP on my access ports?

I'm going to replace some old "central" access switches to some Cisco Catalyst 2960X, and I'm not sure what to do on their STP configurations. For this network, we have some "central" access switches, that connect some hosts and some unknown…
Maurício Mota
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6
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2 answers

STP Packet on specific interface eth1

I have an issue related to some stp packet that being sent every 1 or 2 second on my server interface eth1. This interface is connected to my stack switch, and the port is in a public vlan. Here is the output I have from the…
upitnik
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1 answer

Traceroute to an internet address when I'm behind a Dynamic-PAT firewall?

Consider this network diagram: In this scenario, the router is performing "Dynamic PAT" (I'm using Cisco's definition) where all "real" or "inside" addresses are mapped to a single outside address provided by my ISP. Can host 192.168.1.20…
alx9r
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2 answers

In and Outbound Dual VRRP connections

I'm trying to setup a redundant route link for our internal network using brocade layer 3 switches. I have setup up VRRP on both the green/blue and red/black networks. The reason for doing this is to simulate an active passive pairing. I thought…
krizzo
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Why is the IPv6 link-local address range fe80::/10 rather than fe80::/64?

RFC 4291 specifies that IPv6 link-local unicast addresses must have a high-order bit sequence of 1111111010, or fe80::/10. However, the same document specifies that the 54 bits following the first 10 bits are zeros: Link-Local addresses are for use…
Ted Quanstrom
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