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6 views

Requesting a DHCPv6 prefix and assigning it to a tun device [closed]

I'm trying to create an IOT border router on a Raspberry Pi that will communicate with some custom IOT devices. The Raspberry Pi will communicate with a hat that has the appropriate radios (802.15.4, ...
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0answers
7 views

Understanding firewalls in details [closed]

I would like to understand how firewalls work in details, and check my understanding of the attack surface. In this context, here are some specific questions : Is it good enough for firewalls to ...
0
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0answers
13 views

in 802.11, when must a station go to the “random fall back slot” mechanism?

i've been reading Michael Gast's 2005 book on 802.11, and he talks about how each station, after it has seized a channel and finished transmitting, will then have its NAV timer expire (along with all ...
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0answers
9 views

Changing DHCP range makes me lose internet access [closed]

Hy, I'm trying to increase my network ip address from: IP DHCPIpv4: 192.168.1.10 - 192.168.1.250 Mask: 255.255.255.0 Server: 192.168.1.254 Gateway: 192.168.1.254 To IP DHCPIpv4: 192.168.0.10 - ...
1
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0answers
17 views

Swapping to new ASA hardware - same configuration - what are the pitfalls?

I am replacing some old ASA 5515 with some new ASA 5516. We are going from a set up whereby we managed the boxes to one where a 3rd party is now managing them. I am currently going through the ...
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0answers
7 views

Run Server in Virtual Box with Client in Host OS - How to enable connection [closed]

The problem I face is the following: I got a license file for a program and have to set up a license server to use it. Since this server software requires a linux OS, I set up a virtual machine in ...
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0answers
20 views

How to tunnel a Ubiquiti network through a Cisco managed Switch?

So, we are looking at installing a Ubiquiti UniFi network for a small office with a team of about 20 individuals distributed across several individual offices. Full disclosure, I'm not a network tech, ...
0
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1answer
21 views

How computer “knows” how and what to respond to particulary ICMP messages

How a computer "knows" what to respond to particular ICMP messages? As is known there are various ICMP messages that differ by type and / or code. For example ICMP type 0 is "echo reply", type 13 /14 ...
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0answers
11 views

IOT WiFi network + mobile cellular internet [closed]

Hello Network Engineers, I have an IOT project that requires a bit of WiFi magic, and I wonder if anyone of you guys have experience on the topic. The scenario is as follows: I have a WiFi hub (...
1
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0answers
21 views

When is the source address of ICMPv6 message types 133, 135 and 136 other than unspecified(::/128) or link-local(fe80::/10)?

According to rfc4861 the source address for Router Solicitation(ICMPv6 type 133), Neighbor Solicitation(ICMPv6 type 135) and Neighbor Advertisement(ICMPv6 type 136) can be an address assigned to the ...
0
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1answer
23 views

Switch to secondary firewall when WAN interface goes down

We are having two firewalls A and B. The model is FortiGate 60E. Both are running in HA where A is primary and B is secondary. The firewalls are running smoothly and traffic is flowing from the WAN ...
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0answers
15 views

SSH works when connecting from outside the local network, but not from within [closed]

When I try to connect to my raspberry pi, from within my local network, I get this message: ssh: connect to host 192.168.0.5 port 22: Connection timed out nmap for the same IP yields: Host is up (0....
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0answers
11 views

VRRP or switch stacking [closed]

What would be the best solution for LAN gateway redundancy? Create switch stack of two switches and assign ip address on some VLAN or keep two switches "separated" and configure VRRP?
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0answers
17 views

How does HikConnect work under the hood? [closed]

I have been trying to understand how HikVision's web access platform, HikConnect, facilitates transmission of video streams from my IP cameras at home to my mobile phone anywhere. Note that I have ...
0
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0answers
17 views

Site to site vpn problem [closed]

I configured site to site VPN. I have ASA 5508 and the other site Fortigate. So I finished all configuration but no ipsec tunnel. ASA log error: 3 Jan 27 2020 15:18:06 Group =...
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0answers
19 views

Network Diagram for an educational center [closed]

I have to make a simple network diagram for a project, its about an educational center. is there anyone who can help? thanks
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2answers
83 views

Configuring a network for 100% isolation (for security)

I'm configuring a LAN for an office. It's a new setup, and therefore there are desktops but no servers and no PC-to-PC communications - everything is on the cloud. The exception to this are several ...
1
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0answers
33 views

Is there a way to check which routes are matched by a term in a routing map?

I have created a prefix-list and I am using it in a route-map. However, my route-map is not working as I expect it to work. ip prefix-list LIST_A seq 5 permit 10.20.20.0/22 ge 32 route-map A-B-OUT ...
0
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0answers
17 views

Network jitter using wifi [closed]

I have a weird issue with my home network but it only happens a few random days. The issue is that I get a lot of jitter suddenly without any explanation. Setup: 1 router serving a 5 GHz network on ...
2
votes
1answer
68 views

How to read a BGP table?

I have come across BGP looking glass where I can see the routing table for public routers. Please find below a public entry: BGP routing table entry for 78.97.0.0/16 Versions: Process ...
0
votes
1answer
69 views

How can I legally get a software upgrade for my Cisco Wireless controller without a service contract so it supports my more recent access-point?

I have a Cisco 5508 Wireless LAN controller and a Cisco AIR-CAP3702I-A-K9 Access point. The WLC release is: 7.0.252.0 The AP is : Cisco IOS Software, C3700 Software (AP3G2-K9W8-M), Version 15.3(...
25
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2answers
4k views

Why does the IPv6 header not include a checksum?

It is stated in Wikipedia that an IPv6 header does not include a checksum. What are the reasons that were behind this decision?
0
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1answer
24 views

Using a VLAN to Completely Isolate Devices from the Internet & Other VLANs

I have a Cisco SG350-10P Managed Switch, and currently have two VLANS on it, the default VLAN 1 and VLAN 10. I want devices connected to VLAN 10 to have no ability to communicate with the internet or ...
0
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0answers
14 views

Unable to Connect to MQTT Broker on Vendor Network (ESP8266) [closed]

My goal is to try and establish a connection with our AWS MQTT via an Internet Provider’s WiFi on port 8883 with the ESP8266. I am using Mongoose OS for this purpose. We are using an AWS MQTT broker ...
0
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0answers
7 views

How to select between two NICs for data transfers between a Windows 10 PC and a QNAP TVS 951X NAS? [closed]

I have two Ethernet adapters on my system. One is the inbuilt Intel 1218-V gigabit nic that came with the Asus Z97 Pro WiFi AC motherboard. I installed an Intel X550-T2 dual port PCIe 3.0 x4 NIC. Now, ...
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0answers
11 views

how to divide traffic packages between two sub-interfaces in Linux [closed]

We Have one main physical interface, for instance, "eth0" and we have two inside Linux sub-interfaces "eth0.1" and "eth0.2". We have some traffic on eth0 and we want to dive traffic packages randomly ...
0
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0answers
26 views

Cisco C3232C 100G Link [closed]

Last week i tried to establish a 100G link in a Datacenter with one of my carriers. Even the sh int eth1/X transceiver detail showed very lambda signal normal at both sides and the switch doesn't seem ...
0
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0answers
23 views

Powerline and 20m cable line to ethernet device [closed]

Because the is no cable tubing in the wall I had to use a powerline adapter to get internet from my router to my basement. The internet connection works fine when I plug in my laptop directly into the ...
0
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0answers
18 views

What is wrong with this CRC calculation? [duplicate]

I have gone through a few documents to understand how to check that an ethernet frame is valid. I do the following calculation, but I can see it is incorrect because it does not result in a crc value ...
2
votes
1answer
43 views

Lightweight AP won't join with Wireless Lan Controller

I'm trying to set up a wireless network, and learn at the same time. I'm using a Cisco 5508 WLC and a AIR-CAP3702I-A-K9 lightweight AP. The problem I'm having is that the LAP won't joing with the WLC. ...
0
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0answers
8 views

ideal/suitable values for “TCP connect timeout” [closed]

I'm configuring ncat and like know suitable values for TCP connect timeout in seconds. I'v googled "TCP connect timeout" and found a lot of different values ranging from 45 to 240 seconds, throught ...
-1
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0answers
19 views

Valid MAC addresses [closed]

I have a problem which asks which of the following MAC addresses represents a valid MAC address: 00-ab-29-fg-17-39 00:65:2d:4f:3c:9b 01:23:45:67:89:ab 01-23-45-67-89-ab I know there ...
0
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0answers
19 views

Is it possible to share vmware VM connection with guest OS? [closed]

I have 3 virtual machine.. My 1st vms has internet connection itself using dial up modem.. How do i share the internet connection from 1st VMs to 2nd and 3rd VMs?.. I have been thinking using some ...
-1
votes
1answer
40 views

What special reserved domain could I use for virtual organization private network? [closed]

Suppose we have a inner-facing network that spans several geographical jurisdiction - this network can only accessed from our offices with special HSM installed, and we want to enable domain-name-...
1
vote
1answer
65 views

Removing VLANs from core trunks (.1q)…?

I am a little embarrassed I do not know the answer to this already, well I think I know the answer but I am not 100% sure and this I need to be 100% sure on. We have several core .1q trunks that we ...
0
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0answers
17 views

What is wrong in this CRC calculation? [closed]

I have gone through a few documents to understand how to check that an ethernet frame is valid. I tried to implement the algorithm described on the wikipedia page (in swift 5.1) : // we run ...
0
votes
0answers
9 views

Http, ping, dns and bandwidth - http connection speed [closed]

My question is how each of above protocols contribute in connection speed. Let suppose an http server S and a client A : Does ping speed depend exclusively on the physical distance between A and S? (...
1
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0answers
21 views

Nexus OS IP SLA Object tracking

I have not configured IP SLA object tracking on nexus OS before and its looks a bit confusing. Can someone help me interpret the following configuration? This example shows that object tracking is ...
0
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0answers
11 views

Ethernet-Wifi Bridge needed for mesh network [closed]

I have an Ethernet only device that has no USB ports. I am looking for an Ethernet to wifi adapter that would work on a mesh network. Most everything I see will only work with a single AP. Does anyone ...
0
votes
0answers
7 views

Connecting my T568A patch to my switch [closed]

I have my home wired up to a T568a terminal. I have tested all the ports with a LAN Tester. I have also tested the cables and all check fine. However, when I connect the cat5e port to my switch, I am ...
3
votes
1answer
18 views

Cisco ASA5585-X replace SSP-20 with SSP-60

We have cisco ASA5585-X with SSP-20 running in production and we need more power so planning to replace SSP-20 with SSP-60 module but not sure we can just hot swap with SSP-20? Does ASA5585-X support ...
0
votes
0answers
15 views

relation between networking and protocols [closed]

Disclaimer: probably all that follows is wrong or flawed. Background Most of the home-networking, and this might be wrong, consist on some signal coming to an antenna that afterwards comes down to a ...
1
vote
1answer
20 views

How does triple handshake avoid establishing connection for duplicate packets(coming later down the line)

The idea behind triple handshake seems to be for duplicates to not cause issues. The way I understand it host sends a sequence x to server. Server acknowledges it and sends it's own sequence y. Host ...
2
votes
1answer
30 views

Why do we need machine learning for QoS classification in SDNs if we have DSCP in IP address for QoS enforcement?

DiffServ (Differentiated services) uses a 6-bit differentiated services code point (DSCP) in the 8-bit differentiated services field (DS field) in the IP header for packet classification purposes. If ...
0
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0answers
26 views

Is a firewall needed on a small office that simply needs internet access? [closed]

I'm planning on porting all of my office's software needs to cloud services that I can access via internet. It's a simple LAN that has a NAT gateway pointing to the open internet. Would a firewall ...
0
votes
0answers
12 views

How to perform the CRC check for an ethernet frame [duplicate]

I have an Ethernet frame of n bytes, ending with 4 bytes that contains the Frame check sequence (32 bit CRC). What calculation do I have to perform to perform the check ? I looked on the algorithm ...
0
votes
0answers
12 views

Reasonable security of RDP VPN access [closed]

An organisation I work with requires that employees be able to connect to machines on their network and log on to them from machines that are not on the network and not joined to the domain. They ...
0
votes
1answer
17 views

Count to infinity under a tricky condition [closed]

I was looking around and couldn't find an answer to a tricky situation regarding count to infinity issue. i was wondering if it can happen in the following context: The following network consists of ...
1
vote
0answers
43 views

Connecting GNS3 Topology to the Internet

I'm trying to connect my small topology to the internet through the Cloud device, but I'm not able to connect to even my own desktop's IP from the virtual router I have. I have Windows Defender rules ...
5
votes
3answers
995 views

Unknown EtherType

I am parsing an ethernet dataframe. It has the form : (destination_mac_6_bytes) + (source_mac_6_bytes) + (ether_type_2_bytes). Usually, I see ethertype like Ox86dd (IPv6). But I came across this ...

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