Questions tagged [router]
For questions about network routers, devices that forward data packets between computer networks, commonly at the network layer (layer 3) of the OSI model.
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Tagging a VLAN or not
I want to create a wi-fi network for guests using access points.
I asked to the IT provider a dedicated network with its VLAN and it is: 172.16.0.0/24 VLAN ID 344
The above network is configured on ...
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How does a switch know when and how to forward traffic to a router
I generally understand how L2 switching works. I want to understand how a switch and router work together to send traffic to a device off the L2 network.
For example. Computer A tries to send ...
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L3 Switch acting both as a router and as a switch for the same packets
I am trying to figure out if an L3 switch is able to act as a switch and as a router at the same time for the same packets. Consider the following architecture:
I would like to set up VRRP for both ...
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Why Ping Reply Succcess from different subnet IPs
In the university lab, i manually added IP in two ubuntu machines. PC1 IP 10.129.2.33 255.255.0.0 and PC2 IP 10.129.2.165 255.255.255.0. I connected first both computers with direct ethernet cable ...
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Two routers connected with a serial line, why they can ping each other without clock rate setting?
I'm pretty new to networking and still learning CCNA stuff. I'm reading a book and as I understand, when you are connecting two routers using a serial line, one router is considered DCE and the other ...
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IP masquerading and nat
what is the difference between IP masquerading and nat?
do both of them have the same limitation?
in the line "IP masquerading cannot provide full internet connections to the hosts which hide ...
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issue regarding broadcast mac address
I read a line saying {Routes do not forward packets coming from one interface having broadcast mac address
(FF:FF:FF:FF:FF:FF)}
what is meant by one interface in that line?
if router cannot broadcast ...
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What is the difference between these two different network security devices?
I have a choice between these two network security appliances, however the only difference I can see is the year and I don't know what that year means.
SONICWALL TZ300 WIRELESS-AC SECURE UPGRADE PLUS ...
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Dual Juniper MX80 problem
We have 2x Juniper MX80 routers with only one currently being actively used. Second one is waiting to take over in the event of disaster. We also have two ISP's that deliver network to our MX80.
We ...
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Is it possible to configure DHCP on a router or UTM firewall for the multiple VLANs on L3 Switch?
I'm working on expanding our office network to accommodate more users/devices. Currently we have the DHCP configured on a UTM firewall(cyberoam ing50) device(cum router) providing IP addresses for ...
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1941W wireless clients losing DHCP IP address [closed]
I am attempting to 'extend' a 192.168.1.0\24 network with an experimental network 192.168.10.0\24 using a 1941W router.
I have configured 1941W to distribute a 192.168.10.0\24 network, with WLAN ...
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Cisco, Router can communicate; hosts cannot
I am learning CCNA related tasks, I have picked up a Cisco 1900 Series router. I am attempting to set it up behind my existing router (Comcast standard router).
My "Real" network is 10.0.0.0/...
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Huawei AR207V - can't set IP address
I can't set an IP address on a Huawei AR207V router because it rejects the "ip address" command.
It's a used but factory reset unit, I'm currently connected on the serial port no other ...
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"Destination host unreachable" when pinging a pc from another network
I tried to build a simple network in Packet Tracer and I get "Destination host unreachable" when I try pinging a PC from another network.
Pinging PCs from the same network works.
When I use ...
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What is BTU/hr gauge of Cisco ISR4461/K9?
I searched everywhere but couldn't find it. If anyone knows the system, can answer?
How much BTU (British thermal unit) /hr uses by this router.
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NAT cannot communicate with 2 network
I have configured BGP for routing and NAT for HQ and Branch. I can ping from windows / server to public IP and also Linux Mint ping to public IP. but, I cannot ping / communicate between network HQ to ...
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Is it possible to have a second ASBR in my OSPF area 0?
I have three routers in area 0, two of which are connected to separate WAN circuits. I have one router that is sending the default route but when I try to add a second router with the configuration ...
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Where can one find how much memory is currently allocated to logbuffer?
Do you know where it can be checked, how much memory is currently being used by the logbuffer?
some-switch#show log | i Buffer|Trap|udp
Buffer logging: level debugging, 2268 messages logged, xml ...
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BGP Best Path Selection Algorithm
According to this cisco document (https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html), shortest AS_PATH is the #4 algorithm in the sequence to evaluate, out of 13 ...
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Cisco ip helper-address
I am looking at the DHCP documentation and i cannot seam to find how to configure the router to use a loopback interface as the relay-agent. My objective is to use option 82 so that the dhcp server is ...
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Static Routing - host to host ping does not work (MikroTik)? [closed]
I'm trying to do static routing using actual devices. Below is my setup:
The left router is a MikroTik RouterBoard hAP lite.
The right router is a MikroTik RouterBoard hAP ac.
I want to ping from ...
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Undo last command(s) in case of losing connection to a Cisco Router
I would like to configure an interface on a remote Cisco router (ISR 4000 series) with IPsec.
The only way to connect to it is through the interface that I am trying to encrypt.
I want to ensure that ...
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Is it possible to assign an IP to a tagged dual-mode port (Brocade)
I have a router (ubiquity USG) and a Brocade FCX648 Layer 3 switch. (I have a second one in a stack, but that's unrelated). The end goal is to be able to connect the switch to my router, provide IPs ...
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Who initiates PPP Keepalives after PPPoE session is Established between Modem and BNG?
Hello Everyone,
In case of DSL Modem , normally service providers employ PPPoE connection between Modem and BRAS (BNG). We all know that when Modem dials , it goes through PPPoE stages namely 1 ) PADI ...
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Combining NAT an tunneling
I was reading a text and a doubt came to mind. Suppose there is an interface in a router that implements NAT. That same interface is the extreme of a tunnel. If I was to send a message through said ...
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One client: static IP vs Static lease DHCP vs. DHCP limited range to 1 slot
I want to attach one client (only 1 maximum) to network router ethernet port. I want to always know the client's IP address, for my port forwarding settings. Using DHCP with range the client IP could ...
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Factory reset Cisco N520-4G4Z-A
I'm having some issues doing a factory reset on above mentioned Cisco box.
I've tried several different key combinations and unfortunately previous owner does not remember password
The examples on ...
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Mistakenly added switch configuration on Cisco router 2951 so now it is showing gibberish data on CLI
I have Cisco 2951 router in which my colleague mistakenly uploaded switch configuration from tftp server. Now it is showing gibberish data on CLI when it boots up. I tried to get into the ROMmon mode ...
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How does an L3 Supported Switch differentiate L2/L3 Packets?
I had a managed or layer 3 supported switch (it can process both layer 2 and layer 3 packets). Now a packet from a connected host comes to it, sending traffic. How does the switch decide to process it ...
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BGP unnumbered on P2MP link
I'm wondering what will happen if BGP unnumbered session is configured on a link that has multiple routers on the other side which are both IPv6-capable and will both reply on RS and produce RA ...
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GNS3 can not ping from ethernet interface to serial interface
So I am doing a Lab for one of my classes involving ipv6 and routing using EIGRP. When I set-up the network and assign the router interfaces with IPV6 address I get an issue pinging the whole network. ...
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Does the control packets flow into a router/switch through forwarding plane? [duplicate]
I know there are two platforms in any networking device separating the control packets from the traffic, which I call control plane and data plane. My question is, how does the control packets enter ...
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How to block advertisement of a prefixes recieved from 1 BGP neighbor to another
I have a eBGP topology as follows:
RTR1 ------ DUT ------ RTR2
(AS100) (AS200) (AS300)
I do not want any routes sent by RTR1 to be advertised into RTR2 by DUT
I do not know what exactly the ...
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Switch vs. Router and sequence of OSI Model [duplicate]
As I understand it:
A switch (layer 2) seems to define a LAN and a router (layer 3) enables communication between distant LANs.
A device on a LAN will give it's MAC address to the switch upon ...
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Difference between Reverse Proxy and Port Forwarding
Well both reverse proxy and port forwarding looks for any incoming packets destined to a particular machine which is present in local network. How both of them are different ?
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Safe to remove ip default-gateway?
We recently changed IP schemes from 192.168.x.x to 10.x.x.x In doing so, I noticed that the prior network engineer had ip default-gateway in the configuration pointing to an old default gateway that ...
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EdgeRouterX not routing traffic [closed]
New to this.
I have a tc4400 modem which works fine: when connected straight to my computer, internet passes.
However when I connect my EdgeRouterX to the modem and ssh into the router, pinging any ...
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Can I use a wireless access point (or two) to extend my existing wireless network? [closed]
In large commercial buildings I typically see several ceiling mounted Wireless Access Points. When moving throughout the building, I do not have to continually reconnect to different networks (or ...
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Loopback interface
I have a theoretical question about the loopback implementation on a router.
I understand that the idea of a loopback interface is that it is a virtual interface which never goes down due to a ...
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Duplicated Vlan ID
I have one flat network with our data center and it is causing as a lot of issues, so i had to design a new network to separate the buildings from the data center, when I designed the new network i ...
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How does router know MAC addresses of computers that are connected to a separate switch? [duplicate]
i am a newbie but i need to understand this ARP thing.
In my company we have a router that has 3 switches connected to it. On the switches there are more than 100 hosts.
I know that switch learns and ...
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Is there a way to know the length of the cable used between the connected SFPs on a switching/routing device?
I have connected two Juniper routers with a QSFP28 optics and I need to find out the length of the optical cable I have used. Is there a command to check that in the router?
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Routing Protocols and sharing information
I am running multiple Protocols on different Routers as so:
R1-RIPv2 EIGRP OSPF
R2-OSPF and RIPv2
R3-RIPv2 and EIGRP
R4-EIGRP and OSPF
This is not a practical exercise, it is just to explore how ...
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Do all devices which use Wi-Fi (802.11) use CSMA/CA?
I know this is quite trivial, but I just want to know if all devices which support Wi-Fi through interface cards/hardware (like laptops/PCs/phones..etc) use CSMA/CA irrespective of their router/...
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Routers FastEthernet interface clock autonegotiation protocol
In routers, for serial interfaces, we need to manually set the clock at the DCE router so that the ends of the connection can communicate. I know that in this way we are using time-division ...
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Using WAN IP for a host instead
I have a single static public IPv4 address from my ISP.
So I understand that i can just forward all traffic using port forwarding to one of my private IPs, but still I am wondering if this is the ...
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ARP Router issue
I have a question when a Router receives ARP request to a host that dosen't exists on the forwarding table for that router does the.
And this Router is not the next hop either will the Router continue ...
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What device manages VLANs?
I understand what a VLAN is and what purpose it serves. However, I'm having a difficult time understanding where VLANs orginate.
Specifically, I know CISCO firewalls, switches, and routers all deal ...
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allow 2 machines to communciate each with their own network? [closed]
2 networks. Network 1 local and i want to be able to receive and send information to network 2 which is at a remote site, branch site. How do i go about connecting both networks so that both machines ...
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Suspect MTR showing incorrect packet loss through router; other tools are not showing loss
Using MTR (sending TCP with or without SYN), I'm consistently seeing packet loss on one intermediate router in the path. UDP does the same. I'm use TCP to avoid the ICMP packet flood limits set.
I ...
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