Newest Questions
16,963 questions
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Can ARP cache expiry can make a device lose 100% of its traffic for 1-2 minutes if its all UDP? [closed]
Let’s say the router sends an ARP request, but shortly after, the device changes its IP address. The router will have an outdated ARP cache for a certain period (60 seconds on Linux, or 2 minutes on ...
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0
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5
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Why does my PC cannot connect to my network over switch? [closed]
I have a modem/router provided by my ISP, to which I connect a home type switch. To this switch, I connect my VOIP phone (which connects successfully to the network), a NAS (again, connects ...
- 101
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0
answers
39
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IKEv2 Issues between Meraki and OPNSense
I have a meraki VPN mesh which consists of 3 meraki firewalls and 1 OPNSense firewall. There are 3 IKEv2 IPsec connections setup on the OPNSense firewall, one for each meraki. They're all configured ...
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0
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6
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How to Handle TLS Certificates for Offline Systems with Unknown IP Address? [closed]
I’m a Software Engineer who’s recently been pushed into a Network Engineering role for my current project, and I’d like some advice on how I could have approached a particular issue more effectively.
...
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0
votes
1
answer
39
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Data link layer and transport layer differences/relationships
Hi I am a network engineering beginner learning about the TCP/IP stack in the context of using web services on an embedded system (processor connected to LTE cellular module).
I am struggling to ...
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votes
1
answer
31
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Connect-Info(77) from Fortigate to Windows NPS
I have a FortiGate and I can connect it to Windows NPS radius, and the simple user test works (under User&Auth>>Radius Servers ...).
I then proceed to setup admin logins to the FortiGate, ...
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0
answers
10
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How to proceed with a 4g proxy farm [closed]
I ended up buying these parts:
x1 Lenovo M710q - i5 7th gen, 16gb ram, 256 ssd (Probably didn't need this much, but I got a great deal so why not)
x1 Sipolar A-805P 20 Ports 2.0 USB HUB
x3 MS2372-153 (...
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11
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Server receives IP from DHCP-server but can not ping gateway [closed]
Summary:
When connecting a HP Proliant Microserver gen8 server running a fresh install of Linux Mint 22.1, using a ethernet cable previously used by a HP laptop with proven internet connectivity, it ...
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11
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Bridging two networks over the internet [closed]
I'm moving my homelab into a datacenter. Yay! I've moved all the important stuff onto a Proxmox server running in my house, and I've shipped a second Proxmox server off to the datacenter. My plan is ...
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23
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Laptop connected to lightweight access point via WLC to access specific VLAN 10 [closed]
This is my network topology and the problem is with L2 which is succesfully connected to LAP which acquires ip address via DHCP from WLC's DHCP pool for management.
L2 cannot manage to acquire ip ...
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vote
1
answer
80
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Pfsense router NAT Redirection not working [closed]
I have a pfSense Router protecting numerous things within my network. However, a few of those things, such as my Ark Server, need to be accessible from inside my network but it doesn't work. It worked ...
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1
answer
36
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Longest Prefix match with entries greater than my IP
I am currently facing a problem and can't get a definitive answer to how the router will decide the correct interface to forward my packet to.
Given that an IP datagram has destination address of 192....
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0
answers
51
views
juniper qfx10k sflow
I have a QFX10002-36Q, and I configured sFlow with the following commands:
set protocols sflow polling-interval 20
set protocols sflow sample-rate ingress 10000
set protocols sflow source-ip 10.x.x....
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0
votes
1
answer
37
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Dell Switch OS does not allow any interface commands
I have recently been tasked to operate a Dell switch and I have to shut down an interface connected to a server.
But the switch OS that it has doesn't allow me to enable/disable the switch ports.
SW1(...
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1
answer
53
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Can you multiplex 5+ ethernet lines such that one of those is selected mechanically or by detection of a signal on that line?
Hi all I'm a relatively new electrical engineer who's been asked to take 5 Cat 5 data lines and feed them to a hub which selects one of them upon receiving data in that line to send to a computer. As ...
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vote
1
answer
102
views
QFX10002 and storm default behaviour
I have a pair of QFX10002-36Q switches, and I want to disable or rate-limit multicast and broadcast traffic to a low value. When I try to configure a storm-control profile using set forwarding-options ...
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26
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cisco snmp OID for l2vpn bgp evpn
how do I find the oid for cisco from l2vpn evpn BGP prefix?
below is an example of snmpwalk output using standard mibs bgp4, and only 3 out of 5 show ip prefixes there.
enter image description here
$ ...
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1
vote
1
answer
33
views
Roaming with versus without the same Mobility groups
I am studying Roaming for my ENCOR exam.
My question is, how exactly does roaming differ if we have an inter-controller roaming scenario where the WLCs are in the same mobility group versus a scenario ...
- 1,011
1
vote
1
answer
92
views
Getting “Network unreachable” in FortiClient 7.0.16 [closed]
I am facing difficulties connecting FortiClient 7.0.16 to the corporate VPN while I am in Colombia.
When I try to connect, I receive the error message “Network unreachable.” I have tested it on ...
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2
votes
1
answer
154
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Dual ISP with default route setup
This is how my topo will look end of the day.
eBGP peer between Edge <---> ISP
eBGP peer between Edge <---> Border-Leaf (I am using 65355 to peer eBGP with Edge )
Inside EVPN/VXLAN ...
- 4,431
0
votes
0
answers
19
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Design question to fetch L2 traffic with sFlow
I need some advice about L2 traffic fetching.
Here's the situation :
I got 2 datacenters where both core switch (Cisco Nexus9000 C93240) are linked each other through a 1GB/s vPC where our VLANs are ...
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3
votes
1
answer
204
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Redundant router-switch connection
I have the following network:
Gateway1 is a dedicated server with Juniper vSRX VM, Switch1 is Juniper QFX5xxx. There are multiple VLANs set up on the servers, so interface mode on the switch is set ...
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0
votes
1
answer
40
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multi-connectivity and splitting of traffic flows
In a 5G or SAGIN-based system, is it feasible for a multi-connectivity-enabled user equipment (UE) to split its traffic and transmit it concurrently over both terrestrial and non-terrestrial networks? ...
1
vote
1
answer
51
views
When a layer 3 switch or a switch with SVI receives a broadcast frame, does the switch decapsulate the frame?
When a layer 3 switch or a switch with SVI receives a broadcast frame, does the switch decapsulate the frame? I was confused on this. I was playing with packet tracer trying to get a better ...
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0
answers
28
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how to convert two routed interfaces between two pair 9k and pair 7k to vPC
We have pairs of N7K and N9k connecting via eigrp (full mesh), each one of the pair connected to two mpls routers, each pair have routing table, I am looking to replace the routed interfaces between ...
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0
answers
17
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Sflow on Nexus returning faulty interface values
Hello fellow networking folks,
I'm currently trying to build a small monitoring solution for multicasts. In our lab we have a Nexus9000 C93108TC-EX running version 7.0. I want to start with this ...
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2
answers
39
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I can't get the correct answer from the Cisco IE-3300-8T2S 17.9.5c
I send a request to Cisco 3300 via MIB Browser. Request for the state of the external alarm contact. 1.3.6.1.4.1.9.9.138.2.0.1 (ceAlarmAsserted). In response, the switch sends Value (NoSuchObject): (...
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4
votes
2
answers
363
views
Correct idea for an IPsec gateway
The purpose of this question is to improve my ability to technically apply the idea of routing specific traffic through an IPsec tunnel before reaching the Internet.
So far the best that I can ...
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0
answers
11
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Nested Fragmentation [duplicate]
If fragmentation only occurs once I can reassemble the package, what if the package is fragmented more than once
For example, a package of 3000 bytes will be sent via an Ethernet MTU link of 1500 ...
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1
vote
1
answer
96
views
vPC not getting configured on Nexus switches even though the config status is green
I have the following status on my Nexus switches regarding the vPC configuration status and I see the number of vPCs configured as zero.
Legend:
(*) - local vPC is down, forwarding via ...
- 111
1
vote
3
answers
222
views
BGP between peers that are 1 hop away?
I was wondering the need for a static route in the example below where its from AS65100 directly to AS65200 - 1 hop away. A BGP is established, so would there be a need/requirement for a Static Route ...
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1
answer
57
views
3 firewalls on a layer-2 switch, 1 acts as a default gateway for all devices
I am currently trying to setup a network madeup of a large layer-2 switch, some computers connected to that switch, 3 Cisco Firepower 1120 ASA Firewalls, and other networks beyond 2 of the firewalls, ...
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0
answers
25
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Does switches have MAC address? [duplicate]
I need help.
Do traditional (unmanaged) switches have their own MAC address? I know that for normal functionality it doesn’t need one, but do they have one anyway to identify the switch in a network? ...
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1
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55
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M-LAG: After migrating the VLAN, network accessibility is limited to one switch
colleagues.
I am solving the task of migrating several VLANs from MikroTik to a newly deployed core network, built from two Huawei CE6863E switches combined using M-LAG.
Objective: remove all internal ...
2
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0
answers
98
views
Server redirecting packet via gateway in local LAN
I have Cisco Nexus tor switch connected with multiple servers on 25G nic. When I am pinging from server1 to server2 I am seeing higher latency in ping. After tcpdump found server replying ping reply ...
- 4,431
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votes
1
answer
43
views
PBR Traffic back to the interface it came from
I am working on deploying a policy based routing. I created the PBR on the router as follows:
ip access-list extended HAIRPIN_NAT
10 permit tcp 10.0.226.0 0.0.0.255 host 212.25.30.227 eq 443
route-...
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1
vote
1
answer
34
views
Arista 7130: How to use authorized_keys with MOS?
I tried ssh-copy-id but I get errors:
Password:
^
% Invalid input detected at '^' marker.
^
% Invalid input detected at '^' marker.
^
I believe MOS doesn't support that command.
How can I ...
- 408
1
vote
1
answer
45
views
juniper qfx10002-36q and 10G ports
I have a Juniper QFX10002-36Q, and I want to install a QSFP-40G-LR4 MPO module in port 9, then connect this optic to a 40G-to-4x10G cassette. Can I use ports 10 and 11 as 40G?
Ports 9, 10, and 11 are ...
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votes
2
answers
73
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Inter Router Communication
I'm doing some background reading on OSPF and EIGRP and Inter Router Communication.
This may sound silly but just wanted a wider perspective. From a routing perspective, all hops would be considered '...
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2
votes
1
answer
125
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Adding a new WIC port to Router errors - Packet Tracer
I'm trying a new Fa Port to my router using HWIC-4ESW, for Example the new port is Fa0/1/0, whenever i try to assign in ip to that interface using the command =>
Router(config)# interface fa0/1/0
...
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1
answer
30
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Optimal method to redirect sniffed data from a TCP stream to a third receiver
what would be the best way to solve the issue as depicted below?
In short, I have a running TCP session between server and client - and I need to send the data coming from the server side to a second ...
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6
votes
3
answers
285
views
Cisco Catalyst Switch: Trunk Configuration Not Allowing Communication with multiple VLANs
I have a Cisco Catalyst Ethernet switch.
I would like to setup this configuration:
Ports 18 and 19 are on VLAN 10.
Ports 20 and 21 are on VLAN 20.
I would like port 22 to have access to both VLANs 10 ...
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9
votes
3
answers
2k
views
Is 223.1.2/24 (sic) correct way to label a subnet?
I ask this because I am reading a famous book Computer Networking, A Top-Down Approach 8th edition, by Kurose and Ross.
On page 352 (pdf) I have this paragraph:
The mentioned figure 4.23 looks like ...
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1
vote
1
answer
85
views
Cisco vPC election process
Quite a bad scenario. I had a power outage after which only one of two Nexus switches came online. It couldn't establish peer link (of course). I believe I have to elect the master manually, but don't ...
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0
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31
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How do DS1, DS2, and DS3 differ from ITU-T G.704?
I like to go to the source documentation to deeply understand topics.
I see the DS1 and DS3 data rates mentioned here:
ITU-T G.704: Synchronous frame structures used at 1544, 6312, 2048, 8448 and 44 ...
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1
vote
2
answers
256
views
Dell N-Series STP root problem
I don't understand what is going on with a switch I just purchased. Sorry I only have a rudimentary knowledge.
I currently I have two switches N3048 core switch which is acting as the root (spanning-...
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vote
1
answer
67
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2 Firepower 1120 Firewalls connected to a layer-2 switch
I am working 2 cisco firepower 1120 firewalls, which are connected to a 5-port layer-2 switch through their "outside"(Ethernet1/1) interfaces, each with an IP address of the form 192.168.1.x ...
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votes
1
answer
59
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FHRP Cisco Reading
I'm currently going over reading material for First Hop Redundancy Protocols
Hot Standby
Virtual Router Redundancy
I don't recall any of this being in CCNA, did I miss this or is it newly covered in ...
- 115
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votes
1
answer
55
views
Determine what is an uplink on Juniper switch
Given, decent size network, switches are mostly Juniper 10Gbps. The goal is to identify uplink interface with some reliability. SSH and SNMP access, as well as Solar Winds statistics are available. ...
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1
vote
1
answer
73
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Network Cable Tone testing frequencies and practical applications
Using the Klein Scout Jr. 2 cable tester, the Tone Testing feature sends Low and High frequencies "tones" through the wires to identify wiring issues.
I couldn't find what are the actual Low ...
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